EPA-600/2 78-006
January 1978
Environmental Protection Technology Series
HIGH PURITY PNA HYDROCARBONS AND
OTHER AROMATIC COMPOUNDS
Synthesis and Purification
Environmental Sciences Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development. U S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-006
January 1978
HIGH PURITY PNA HYDROCARBONS
AND OTHER AROMATIC COMPOUNDS
Synthesis and Purification
by
E.J. Eisenbraun
Department of Chemistry
Oklahoma State University
Stillwater, Oklahoma 74074
Grant No. 803097
Project Officer
James E. Meeker
Atmospheric Chemistry and Physics Division
Environmental Sciences Research Laboratory
Research Triangle Park, North Carolina 27711
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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DISCLAIMER
This report has been reviewed by the Environmental Sciences Research
Laboratory, U.S. Environmental Protection Agency, and approved for pub-
lication. Approval does not signify that the contents necessarily re-
flect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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ABSTRACT
The synthesis and/or purification of a group of polynuclear aromatic
(PNA) hydrocarbons commonly found as pollutants in the environment are
described. The steps used in a given synthesis, the experiments carried
out, and a presentation of some instrumental data obtained in establishing
the identity and purity of the hydrocarbons are included. Publications
derived from this work are cited.
This report was submitted in fulfillment of Grant Number 803097 by
Oklahoma State University under the sponsorship of the U.S. Environmental
Protection Agency. This report covers a period from May 1, 1974 to
April 30, 1977, and work was completed as of May 1, 1977.
iii
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CONTENTS
Abstract ill
Schemes • • vii
Figures viii
Acknowledgments • • ix
1. Introduction . . 1
2. Conclusions 3
3. Recommendations . 4
4. Materials and Methods 6
Hydrocarbons Obtained by Direct Purification — Purification
Techniques and Safety Precautions 6
Purification Techniques — Recrystallization ..... 6
Purification Techniques — Picric Acid Complexation . . 7
Purification Techniques — Soxhlet Extraction ..... 7
Purification Techniques — Zone Refining, Liquid
Chromatography and Sublimation 10
Safety Measures ,'. • • 11
Analytical Methods j. . . 13
Synthesis of Polynuclear Aromatic Hydrocarbons Listed in
1974 Proposal . . 14
a. Anthanthrene (5) . . 14
b. Benz[a]anthracene (6) . . 16
c. Benzo [])] fluoranthene (J7) 16
d. Benzo [jj f luoranthene (J5) 17
e. Benzo [k:] f luoranthene (9) 18
f. Benzo[ghi]perylene (10) 19
g. Benzo[^]pyrene (11) 20
h. Coronene (12) 20
i. Indeno[l,2,3-cd]pyrene (13) 21
j. Perylene (14) 22
k. Triphenylene (15) 22
Hydrocarbons Added Subsequent to the 1974 List ...... 23
Benzo [^jphenanthrene (44) 24
Tetrahydropyrene (46) and Hexahydropyrene (47) .... 24
1,2,3,4-Tetrahydroanthracene (50) 25
v
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5. Experimental Procedures 26
Purification of Solvents 26
Purification of Chrysene (1), Fluoranthene (2), Pyrene (3),
and 1,3,5-Triphenylbenzene (4_) 27
Synthesis and Purification of Anthanthrene (5) 28
Synthesis and Purification of Benz[ji] anthracene (6) 29
Synthesis and Purification of Benzo[b] fluoranthene (_?) .... 29
Synthesis and Purification of cis,anti-4,5,6,6a,6b,7,8,12b-
Octahydrobenzo[JJf luoranthene (27) and Benzo [jjf luoranthene
(8) . 30
Synthesis and Purification of Benzo [k] f luoranthene (_9) ... 32
Synthesis and Purification of Benzo [jghi] perylene (10) 32
Synthesis and Purification of Benzo[ji]pyrene (11) 34
Synthesis of Coronene (12), Indeno[l,2,3-£d]pyrene (13), and
Perylene (14) 36
Synthesis and Purification of Triphenylene (15) and _s-Dodeca-
hydrotriphenylene (40) 36
Synthesis and Purification of Benzo[£]phenanthrene (44) ... 39
Synthesis of Tetrahydropyrene (46), Hexahydropyrene (47), and
1,2,3,4-Tetrahydroanthracene (50) 40
6. Results and Discussions 55
Footnotes and References 57
List of Theses and Publications 60
vi
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SCHEMES
Number Page
1 Anthanthrene (5) 15
2 Benz[a)anthracene (6) 16
3 Benzo[b]fluoranthene (2.) 17
4 Benzo [Jj fluoranthene (8) 18
5 Benzo[k]fluoranthene (9) 19
6 Benzo[ghi]perylene (10) 19
7 Benzo[a]pyrene (H) 20
8 Coronene (12) 21
9 Indeno[l,2,3-cd]pyrene (13) 21
10 Perylene (14) 22
11 Triphenylene (15) 22
12 Benzo[cjphenanthrene (44) 24
13 Tetrahydropyrene (46) and Hexahydropyrene (47) 25
14 1,2,3,4-Tetrahydroanthracene (50) 25
vii
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FIGURES
Number Page
1 Soxhlet apparatus used to purify PNA hydrocarbons through
absorption on alumina and as a picric acid column 8
2 Improved Soxhlet apparatus used in the purification of PNA
hydrocarbons • 9
3 Apparatus for sublimation of PNA compounds 11
4 Apparatus for increased safety in extraction of PNA hydrocarbons 12
5 Apparatus to clean sintered-glass funnels 13
6 PMR Fourier transform spectrum of chrysene (1) in CDC1, at
100 MHz 41
7 Proton magnetic spectrum of fluoranthene (2) at 100 MHz in
CDC13 42
8 Proton magnetic spectrum of pyrene (3_) at 100 MHz in CDC13 ... 43
9 Proton magnetic spectrum of 1,3,5-triphenylbenzene (4_) at 100
MHz in CDC13 , 44
10 Proton magnetic spectrum of benz[a]anthracene (6) at 100 MHz in
CDC13 45
11 Proton magnetic spectrum of benzo[_b] fluoranthene Q) at 100 MHz
in CDC13 46
12 Proton magnetic spectrum of benzo[Jj fluoranthene (8) at 100 MHz
in CDC13 47
13 Proton magnetic spectrum of benzo[k]fluoranthene (9) at 100 MHz
in acetonitrlle 48
14 PMR Fourier transform spectrum of bnezo[ghi]perylene (10) in
CDC13 at 100 MHz 49
15 Proton magnetic spectrum of benzo[j|]pyrene (11) at 100 MHz in
CDC13 50
16 Proton magnetic spectrum of triphenylene (15) at 100 MHz in
CDC13 51
17 Proton magnetic spectrum of benzo [_c]phenanthrene (44) at 100 MHz
in CDC13 52
18 Proton magnetic spectrum of cis,anti-4,5,6,6a,6b,7,8,12b-
octahydrobenzofjj fluoranthene (27) at 100 MHz in CDClo 53
19 Proton magnetic spectrum of ^-Dodecahydrotriphenylene (40) at
100 MHz in CDC13 54
viii
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ACKNOWLEDGMENTS
Drs. N. R. Beller, University of New Mexico, H. H. Chen, University of
Texas, and T. Rangarajan, Annamalia University of Madras, India, served as
Research Associates.
L. L. Ansell, Ph.D. 1976, F. U. Ahmed, M.S. 1975, and A. R. Taylor,
M.S. 1974, received partial support from the project in obtaining their
degrees.
C. E. Browne, D. L. Bymaster, K. D. Cowan, A. G. Holba, H. Storr,
E. H. Vickery, and P. Vuppalapaty also have received partial support.
As spokesman for the group, the Principal Investigator gratefully
acknowledges the financial assistance these chemists received from the
Environmental Protection Agency.
During the early phase of the study, the American Petroleum Institute
provided some Joint assistance and permitted use of equipment and supp les
to further the work. We are grateful for this help. In a similar manner,
our current synthesis effort for the Thermodynamics Research Group of the
U. S. ERDA station at Bartlesville, Oklahoma allows for shared facilities
and some joint effort.
Our project received invaluable assistance from the Analytical Div-
ision of the Continental Oil Company, Gulf Research and Development Co.,
Exxon Research and Engineering Co., and Battelle, Pacific Northwest Lab-
oratories in the form of mass spectrometric, nmr, and liquid chromatographic
determinations.
ix
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Other mass and nmr determinations were obtained from Oklahoma State
University Chemistry Department instruments. The use of the Varian XL-100
nmr spectrometer obtained through NSF Grant CHE76-05571 is gratefully
acknowledged.
We thank Mr. James E. Meeker and Dr. E. Sawicki of the Chemistry and
Physics Laboratory, Environmental Sciences Research Laboratory, Research
Triangle Park, North Carolina and the personnel of the Office of Research
Operations, Oklahoma State University, for courteous and helpful assistance.
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SECTION 1
INTRODUCTION
This research project was initiated in response to a need expressed by
the Chemistry and Physics Laboratory, National Environmental Research Center,
Research Triangle Park, North Carolina 27711, for 10-gram samples of pure
polynuclear aromatic compounds to be used as instrumental standards.
The alphabetized list of the desired aromatic compounds with their
current status follows:
acridine benzo [ji]pyr en e
b a
anthanthrene benzo[ ej pyrene
benz[a]acridine chrysenea
benz[j:] acridine coronene
benz[a]anthracene fluoranthene
benzo[b]fluoranthene dibenzo[a.h]anthracene
benzo[j]fluoranthene pyrenea
benzofk]fluoranthene indeno[l,2,3-cd]pyrenec
benzo[mno]fluoranthene perylene
llH-benzo[J>]fluorene 1,3,5-triphenylbenzene
benzo[ghi]perylene triphenylene
Turified from commercial material and shipped. Synthesized and
shipped. Current work, future work.
During the past three years we have synthesized and/or purified 12
hydrocarbons from the above list and are continuing work on several other
1
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ones as Indicated. Also, we have supplied benzo[jz]phenanthrene as an addi-
tional hydrocarbon requested by the sponsor. In addition, we have supplied
two other related hydrocarbons which became available as part of the project
work or resulted from synthesis carried out for the American Petroleum
Institute and/or the Energy Research Development Administration. This total
of 15 hydrocarbons prepared as project effort, particularly the completely
aromatic ones, are of the type found as products of combustion, petroleum
refining, and in the exhaust of automobile engines.
Thus the reported work divides itself into purification of four
hydrocarbons available from commercial sources, and synthesis and purifica-
tion of eleven other hydrocarbons.
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SECTION 2
CONCLUSIONS
It ±s well accepted that PNA hydrocarbons and related aromatic compounds
are ubiquitous in their environmental distribution. Despite efforts to con-
trol and reduce their presence, there is a good possibility that this dis-
tribution in the environment will actually increase until more effective
control is realized. We base this assumed increase on several factors —
increased use of aromatic hydrocarbons in an increasing number of internal
combustion engines, projected increase in burning of coal, increased use of
heavy oils for space heating, projected processing of coal to coal liquids
and subsequent Increased use of coal oils, and finally, frequent report of oil
spills and other disasters which release hydrocarbons to the environment.
This gloomy view is offset by the results of increased efforts to con-
trol handling and usage and by improvements in technology. Consequently,
since reference PNA compounds occupy a central position in studying and gain-
ing an understanding of environmental problems raised by their presence, it
follows that there will be an increased need for such materials. Since many
of these hydrocarbons are not available in adequate purity and quantity, it
becomes desirable to affect their synthesis to alleviate this need.
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SECTION 3
RECOMMENDATIONS
In the preceding section it was pointed out that the need for pure PNA
hydrocarbons will probably Increase. This projected need may, in part, be
met by commercial suppliers. However, PNA hydrocarbons from some commercial
sources may contain difficultly removed impurities, as is usually the case
for compounds derived from coal tar and coking operations. Thus, it becomes
preferable in many cases to synthesize hydrocarbons rather than use commer-
cially available ones in obtaining pure samples.
Future work in this area should be preceded by a list of needed com-
pounds, as was done in this .project. This list should contain more com-
pounds than are to be synthesized so that alternate synthesis possibilities
can be developed to replace syntheses or purifications which fail or become
too expensive for practical completion.
The information as to which structures should be selected for synthe-
sis is dependent on which compounds are considered to be important in the
field and whether they are commercially available. Those PNA hydrocarbons
which are products of combustion and prominent members of petroleum resi-
dues appear to be most important. However, as the utilization of coal
increases and coal liquids become more important, other structural types
will obviously emerge. Therefore, long-term studies involving polynuclear
aromatic compounds found in the environment should include compounds found
-------
to be constituents of coal liquids and the end products of coal liquid
utilization.
Since the instrumental capability for detecting and measuring stable
(non-radioactive) isotopes of carbon, nitrogen, and oxygen is now rapidly
maturing, and such instrumentation is becoming widespread, and further,
since stable isotopes are becoming more plentiful and in some cases
cheaper, a program should be considered which provides for the systematic
synthesis of appropriately labelled compounds. The selection of structures
would present a difficult choice. However, some PNA compounds which are
most frequently encountered in environmental problems but are not commer-
cially available as labelled materials could be considered for initial
synthesis. Compounds containing a greater than normal abundance of stable
isotopes have an advantage over those containing unstable isotopes in that
their use as tagged molecules in environmental studies does not raise the
health problems associated with radioactive tracers. In addition, tagged
reference compounds containing stable isotopes can be expected to have good
shelf life.
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SECTION 4
MATERIALS AND METHODS
The PNA hydrocarbons cited below are divided into three categories of
synthesis and purification in order to present a division of the effort
involved in the preparation of the pure samples and to connect their rela-
tionship to the original proposal.
HYDROCARBONS OBTAINED BY DIRECT PURIFICATION ~ PURIFICATION TECHNIQUES AND
SAFETY PRECAUTIONS
Hydrocarbons .1-*• .4 were commercially available at a reasonable cost
and were thus purified without further modification. Their structures and
the amount supplied follow:
Chrysene (1)
Fluoranthene (2)
Pyrene (_3)
1,3,5-Triphenyl-
benzene (4)
10.6 g. 10.4 g. 13.5 and 8.3 g. 11.6 g.
Purification Techniques — Recrystallization
In general, purification of commercial PNA hydrocarbons, many of which
are derived from coal tar, is difficult, and more extensive processing is
frequently required than for PNA hydrocarbons obtained from synthesis.
The usual route to purification, since PNA hydrocarbons are solids, is
to first crystallize from common solvents, e.g., benzene, toluene, isohexane,
6
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methanol, ethanol, and possibly chloroform or dichloromethane. These solv-
ents must either be pure commercial solvents or solvents reprocessed from
cheaper grades.
Because of the volumes of solvents required and to reduce the costs, we
redistill and reprocess our solvents before use. This usually involves dis-
tilling from glass vessels and may include prior treatment with sulfuric
acid, silica gel and/or alumina or other adsorbing agents.
Once it is established through instrumental studies (gc, Ic, nmr, mass
spectrometry) that recrystallization does not offer additional purification,
we usually try complex formation as the next step.
Purification Techniques — Picric Acid Complexation
Picric acid is usually the best choice for preparation of a complex
with a PNA hydrocarbon because of its broad effectiveness and lower cost.
1,3,5-Trinitrobenzene is effective but expensive. 2,4,7-Trinitro-9-fluore-
none is also effective, but as with- 1,3,5-TNB, is expensive and has the
added disadvantage of being a suspected carcinogen.
A common procedure in utilizing picric acid is to mix the aromatic hyd-
rocarbon and picric acid as solutions in 95% ethanol and then allow th
resulting picrate complex to crystallize. The crystalline complex is fil-
tered and recrystallized from 95% ethanol or other common solvent. To
recover the aromatic hydrocarbon from the complex, the complex may be dis-
sociated by treating with aqueous ammonium or sodium hydroxide and then
extracting with ether or by using the Soxhlet extraction technique described
in the following section.
Purification Techniques — Soxhlet Extractions
Prior to our beginning this project, we developed a Soxhlet extraction
2
technique in which the dried picrate-organic hydrocarbon complex is placed,
-------
as a layer, on top of a column of basic alumina contained in a Soxhlet appar-
atus similar to that in Fig. 1. The picrate-organic hydrocarbon complex is
then extracted with isohexane to leach out the PNA hydrocarbon which, in
turn, readily elutes through the basic alumina into the collection flask.
Since picric acid is insoluble in isohexane, it remains behind as a layer
above the alumina. However, if benzene or more polar solvents are used,
picric acid will dissolve and considerably more alumina is required.
f 55/50
Petroleum
tthtr -
Sptnt Picric
oeid
Adsorbed Picric
ocid ^
Boiic
Alumino—
Sinl*r«d- — 1
Olot* plot*
'I
1 i
08
0 I t
Seou •
Figure 1. Soxhlet apparatus used to purify PNA hydrocarbons through
absorption on alumina and as a picric acid column.
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Recently we have improved the Soxhlet apparatus (current design is
shown in Fig. 2) to include a Teflon stopcock which enables control of
liquid level in the Soxhlet apparatus. In many cases it is desirable to
keep the picrate covered with a liquid layer to increase efficiency of
extraction through direct contact with liquid, but also to increase the flow
rate as a result of pressure developed from the liquid head.
This new Soxhlet apparatus has enabled us to develop an efficient and
safer approach to the separation and purification of PNA hydrocarbons. In
Sintered
glass
plate
Teflon _
stopcock
d
/
*
55/50
Inches
Figure 2. Improved Soxhlet apparatus used in the purification of PNA
hydrocarbons
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this use, the lower portion of the Soxhlet chamber is charged with basic
alumina, which in turn is covered with a layer of lightly tamped picric acid.
The hydrocarbon mixture is then layered above the picric acid. Refluxing
hexane or benzene dissolves the hydrocarbon mixture and introduces it onto
the picric acid. Those hydrocarbons which are capable of picrate formation
are retained, whereas those which do not form a picrate or a less firmly
complexed picrate migrate rapidly through the picric acid and alumina layers
4
and are eluted first into the collection flask.
Purification Techniques - Zone Refining, Liquid Chromatographyand Sublimation
We have used zone refining as a final step in purification. Our experi-
ence has shown that a zone-refining apparatus operating with a vertical tube
is much more reliable, since vertical tubes rarely break during operation,
whereas our attempts to use a horizontally mounted apparatus usually resulted
in a ruptured tube.
We have used liquid chromatography (Ic) for analysis, but not for puri-
fication of samples. Our future purification procedures may include prep-
arative Ic, since we now have such instrumentation available.
Sublimation is usually the final step in purification of a PNA hydro-
carbon, to insure that no polymeric material or detritus remains. To pro-
vide a sublimed sample and to avoid the possibility of rubber particles or
stopcock grease being carried to the sample when vacuum is released, we
devised the apparatus shown in Fig. 3, which incorporates a sintered glass
disc to act as a filtration barrier when the vacuum is released. The 0-ring
seal removes the need for using stopcock grease with the ball joint.
Examples in which these techniques were used are presented in the
Experimental Section.
10
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vacuum
sintered glass filter
0-ring ball joint
fused salt bath
Figure 3. Apparatus for sublimation of PNA compounds
Safety Measures
Since several of the hydrocarbons described in this report are known or
suspected carcinogens, we have stressed careful handling of materials to
avoid personal contact during synthesis, purification and packaging. We have
attempted to develop a safety concept which includes careful planning of
experiments and handling. This includes monitoring activities with UV lamps
to detect spilled material through fluorescence.
It is our standing policy to have our chemists wear aprons, gloves,
surgical face masks and sleeve protection when exposure is eminent. During
the packaging of the solid hydrocarbons, we use disposable glove bags and
an inert gas (nitrogen or argon) to avoid personal contact.
As an added safety measure we routinely incorporate stainless steel
catch basins in the apparatus setup as in Fig. 4 to reduce the chance for
contamination of the laboratory should glassware become cracked or broken
11
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Spray trap,
» 35/25
Condenser. Urge bar*
and high capacity.
I 35/25
Polynuclcar aromatic
hydrocarbon
Alumina
Soxhtel.wtth sintered
disc. I 55/50 and 24/40
Heating mantle
Catch basin
Magnetic stlrrer
Scale- inches
Figure 4. Apparatus for increased safety in extraction of PNA hydrocarbons.
during a reaction. In addition, we also equip apparatus with appropriate
collection traps as shown in Fig. 4, so that if bumping or a sudden surge of
vapor and/or liquid results during an extraction or reaction, the material
flooding through the condenser will harmlessly spill into a collection
chamber rather than spray out into the lab.
To minimize contamination of samples during purification, we have found
the apparatus shown in Fig. 5 to be useful in cleaning Buchner funnels. As
an added precaution, any glassware including sintered-glass funnels which
has been in contact with carcinogenic materials is fired at the annealing
temperature to burn off any carbon. This Insures that no carcinogenic mat-
erial survives and that there is no cross contamination of samples.
12
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To candtnstr
Adapted from
39/26 flask
Buchner funnel,
plastic
Neoprene filter
adapter
Adapter from
±35/25 flask
Flask. £ 35/25.
Heating mantle
- -Catch basin
stainless steel
Magnetic stlrrer
Buchner funnel,
plastic. Disc removed
Buchner funnel, 200ml
Figure 5. Apparatus to clean sintered-glass funnels.
Analytical Methods
The analysis of the hydrocarbons cited elsewhere in this report and the
various intermediates leading to their synthesis was carried out through use
of instruments in our laboratories (tic, glc, and some Ic), those of the
Chemistry Department (mass spectrometry and nmr) and in some industrial lab-
oratories. The latter are identified under acknowledgments. To avoid repe-
tition, these instruments are cited in Section V, Experimental Procedures.
We have obtained photo-reduced copies of pmr spectra of all hydrocarbons
shipped to EPA except anthanthrene (3), which was too insoluble for an ade-
quate spectrum. Chrysene (1) and benzo[ghi]perylene (10) were also too
insoluble for conventional pmr spectra. However, use of Fourier-Transform
techniques permitted accumulation of pmr spectra for ^ and JLO shown in Fig.
6 and Fig. 14 respectively. Excluding these latter figures, the spectra of
the other hydrocarbons are shown in Fig. 7-19.
13
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SYNTHESIS OF POLYNUCLEAR AROMATIC HYDROCARBONS LISTED IN 1974 PROPOSAL
The synthesis of 11 PNA hydrocarbons cited In the original proposals is
presented below. These are listed alphabetically and thus are not arranged
In the order In which they were prepared. The structures are presented
later In the synthesis scheme as indicated.
a. Anthanthrene (5), Scheme I
b. Benz [ji] anthracene (6), Scheme II
c. Benzo []>] fluoranthene (J)» Scheme III
d. Benzo [Jj fluoranthene (B) , Scheme IV
e. Benzo[k]fluoranthene (9), Scheme V
f. Benzo[ghi]perylene (10), Scheme VI
g. Benzo [ji]pyrene (11), Scheme VII
h. Coronene (12), Scheme VIII (part of current work)
i. Indeno[l,2,3-cd]pyrene (13) Scheme IX (part of current work)
j. Perylene (14), Scheme X (part of current work)
k. Triphenylene (15), Scheme XI
a. Anthanthrene (5)
Anthanthrene (5) was synthesized as shown in Scheme I. For the mos.
part, this synthesis followed a published procedure. However, the prepara-
tion of 5^ presented an opportunity to establish the structure of the new
hydrocarbon 21 and to demonstrate that HI-P, is a superior reagent in
affecting removal of benzylic carbonyl groups, a* e.g., JL8 -» 19 and 20 •*• 21.
Ketone 18 and hydrocarbon 19 were prepared in this work to help establish the
structure of the monocyclization product 17. Hydrocarbon j.9 was subsequently
prepared in an independent synthesis for the American Petroleum Institute. a*
The new hydrocarbon 21, an intermediate in the synthesis of anthanthrene (5),
14
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was isolated after deoxygenation of diketone JO with HI-P,. * The
structure of 21 was determined by comparison of its uv spectrum with that of
pyrene. These spectra were in good agreement and the expected bathochromic
shifts of absorption maxima as the result of the presence of the two satur-
ated rings were observed.
SCHEME 1
a
C02H
20
21
a
ZnCl2, CH3C02H, A. Cu, quinoline, A.
?Pd/C, A.
, A. T»PA, A.
A 12.3-g sample of _5 in 33 ampoules and 8 vials was provided.
15
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b. Benz[a]anthracene (6)
This hydrocarbon was prepared using Scheme II. The products of Scheme
II were examined in detail and some improvement over published work was
9
realized. In summary, hot sulfuric acid with added boric acid and liquid
HF are inferior to hot PPA in affecting cyclization of 22 to _23. ' ' We
also learned that commercial aluminum isopropoxide was ineffective and that
freshly prepared material is required.
SCHEME 2
aAld3, £-dichlorobenzene. "PPA, A; or H2SO^ + HoBO,, A; or liq. HF.
°Al[-0-C6Hn]3, C6HUOH.
A 13.0-g sample of j> in 14 vials and 30 ampoules was provided.
c. Benzo[b3fluoranthene (7)
This compound was successfully synthesized as shown in Scheme III.'
However, before we used this route, we first made several attempts to carry
13
out the acid-catalyzed cyclization of 9-benzylidene fluorene under a variety
14
of conditions. We had hoped that the preparation of chloro-9-benzyli-
denefluorene (24) could thus be avoided. We noted that 9-benzylfluorene was
a byproduct in the formation of 9-benzylidenefluorene. Presumably the reac-
tion of benzaldehyde and alkali (Cannizzaro conditions) causes this
16
-------
reaction. Vie also tried photocyclization of 9-benzylidenefluorene without
14
SCHEME 3
results.'
CHO
a
, KOH, piperidene, A. Quinoline, KOH, A.
A 15.2-g sample of 7. in 13 vials (4.5 g) and 29 ampoules (10.7 g) was
provided.
d. Benzo[j]fluoranthene (8)
This hydrocarbon resulted from the extension of an earlier study of the
octahydrobenzofjjfluoranthenes J26 and 27_ shown in Scheme IV. Aromat Lzation
of pure 2j or 2T_ or a mixture leads to the yellow-colored j8. If 25^ is present,
it is converted to J8 which is difficult to remove. The conditions for forma-
tion of 25 and/or cyclization to _26 and TL were studied. Amberlyst-15 does
not yield the same mixture of _26 and 27_ as is obtained with other acidic
reagents (PPA, P^j H2S04).15'16
17
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SCHEME 4
OH
25
jj
a(ibu)2A!H. Oxalic acid, A. °Amberlyst-15, C6H5. dc, A. 6Pd/C.t A,
A 10.1 g sample of 8_ in 88 vials was provided.
e. Benzo[k]fluoranthene (9)
Hydrocarbon ^ was prepared by a known procedure involving condensation
of acenaphthenequinone and £-phenylenediacetonitrile as shown in Scheme •
17 18
V. ' This led to the dicyanobenzo[k]fluoranthene (33) which was subse-
quently hydrolyzed and decarboxylated to 1J3 by heating in the presence of
phosphoric acid.
18
-------
SCHEME 5
CN
CN
aAniline, A. H-jPO^, A.
A 10.3-g sample of j) in 47 ampoules (5.6 g) and 19 vials (4.7 g) was
provided.
f. Benzo[ghi]perylene (10)
This hydrocarbon was synthesized via Scheme VI from 1-tetralone. '
As indicated in the scheme, this synthesis route is capable of providing
5,6,9,10-tetrahydrodibenzo[£d]phenanthrerie (30) and dibenzo[cd]phenanthrene
(31) as well as the target hydrocarbon benzo[ghi]perylene (10).
SCHEME 6
31
aAl, C6H6, C2H5OH, HgCl2. &C
C10H18' A'
/»
•'
30
f
10
Maleic anhydride, A.
Cu, A. JPd/C, A. yNBS, CC14, A;
A 10-4-g sample in 89 vials was supplied.
, A.
19
-------
g. . Benzo[a]pyrene (11)
21 22 23
The route shown in Scheme VII was used to prepare 11. ' ' We
consider the synthesis of .11 to be troublesome. The deoxygenation of JJ2 to
2
33 is best carried out with HI-P,; other methods of reduction (Wolff-
Kishner and Pd/C hydrogenolysis) afforded low yields of product and caused
22 ?
some side-chain cleavage. Cyclization of JJ3 to J4 was done in liquid HF.
2 22
PPA in this case gave poor yields of impure product. '
11 .35 3A
/r ' "h s* s7
A1C13, C6H6, succinic anhydride. HI, P4, A. HF. (ibu)2A!H, C6H6.
SPd/C, A.
A 9.7-g sample of 11 in 41 ampoules and vials was provided.
h. Coronene (12)
This hydrocarbon is being prepared as shown in Scheme VIII. The syn-
thesis is dependent upon the product from Scheme VI and is currently being
_., . 20,24
studied. '
20
-------
•SCHEME 8
a
10 12
, A. Quinoline, Cu20, A.
i. Indeno[lt2,3-cd]pyrene (13)
Hydrocarbon 13 is being prepared as shown in Scheme IX. As in Scheme
VI, this route is capable of producing additional hydrocarbons — 36. 37,
25
and 38. We believe this synthesis of 13 to be new and it represents a
26
considerable improvement over earlier preparations.
SCHEME 9
CuBr2,
A. Mg, ether, initiated by CHjMgBr. CCyclohexanone, A.
Amberlyst-15, A. eCl> Amber lyst- 15, A. ^Pd/C, A. ^A1C13, NaCl, A.
21
-------
24
j. Perylene (14)
The route in Scheme X appears to be new as a source of perylene (14)
The yield is low (12%), but since only one step from the commercially avail-
able material 39 is involved, we consider this to be an improvement over
27
previously described procedures.
SCHEME 10
a
14
39
Quinoline, Cu^O, A.
k. Triphenylene (15)
Triphenylene (15) was originally considered for purification from com-
mercially available material. However, the synthesis route in Scheme XI
showed promise and we thus avoided the usual "coal tar" contaminants. This
28
route also provided symmetrical dodecahydrotriphenylene (40). Since both
is was
29 30
15 and 40 were obtained in high purity, ' we consider that synthesi
justified. A 12.3-g sample of j.5 in 96 vials was supplied
SCHEME 11
OH
^
0
0
aKOH. £CH3C6H4S02C1, A. °Pd/C, A.
22
-------
HYDROCARBONS ADDED SUBSEQUENT TO THE 1974 LIST
An alphabetical list of the 21 aromatic compounds requested by the
Chemistry and Physics Laboratories, NERC, RTF, NC, and their current status
is shown on page 1 (Section 1, Introduction). Subsequently benzo[jc]phenan-
threne (44), which has been supplied, was added to the list during the 1976
renewal at the request of the sponsor.
The structure and status of other hydrocarbons (including benzo[cjphen-
anthrene) currently being prepared for the Chemistry and Physics Laboratory,
NERC, ATP, NC, are given below.
This group of hydrocarbons came under consideration because some occur
as intermediates (27, 30, '40) in the synthesis of specific hydrocarbons or
are easily obtained as a side product of a given synthesis (31). Some hydro-
carbons in this group resulted in part from collaborative efforts with the
American Petroleum Institute Research Project in the early phase of the work
and more recent syntheses for the thermodynamic group at the ERDA station in
Bartlesville, Oklahoma (27, 46, 47, 50). The preparation of the hydrocarbons
in this group may be traced by reference to the specific synthesis scheme
numbers shown below. Schemes XII, XIII, AND XIV, which do not appear in the
earlier part of this report, are subsequent to this group of hydrocarbons.
Benzo[c]phenanthrene (44), Scheme XII below, shipped 9.7 g in 87 vials
Dibenzo[c,d]phenanthrene (31), Scheme VI (p. 19), current work
jj-Dodecahydrotriphenylene (40), Scheme XI (p. 22), shipped 8.8 g in 62
vials
l,2,3,3a,4,5-Hexahydropyrene (47), Scheme XIII below, current work
cis. anti-4.5.6.6a.6b.7.8.12b-0ctahydrbbenzo[j]fluoranthene (27),
Scheme IV (p. 18), shipped 10.3 g in 51 vials
23
-------
1,2,3,4-Tetrahydroanthracene (50). Scheme XIV below, current work
Tetrahydrodibenzo[c_,ji]phenanthrene (30), Scheme VI (p. 19), current work
4,5,9,10-Tetrahydropyrene (46), Scheme XIII below, current work
Benzo[c]phenanthrene (44)
Benzo[£]phenanthrene (44). added to the list in the 1976 renewal, was
prepared by the procedure shown in Scheme XII. This preparation was achieved
with some improvement (33% vs. 16%) over the published report.
SCHEME 12
18,31
41
e or f
44
43
, ether. Oxalic acid, C,H5, A. °Maleic anhydride, A.
0 f
methylnaphthalene, A, or S, A. Ba(OH)2, Cu, A. JQuinoline, Cu, A.
A 9.7-g sample of 44 in 87 vials was supplied.
Tetrahydropyrene (46) and Hexahydropyrene (47)
Hydrogenation of pyrene (3) with Pd/C in acetic acid leads to the tetra-
32
hydro and hexahydro products 46 and 47. The separation and purification
of these hydrocarbons was achieved through use of a picric acid column, since
4
46 does not form a picrate whereas 47 does. Hydrocarbons 46 and 47 are
currently undergoing purification.
24
-------
SCHEME 13
H2, Pd/C
H2, Pd/C
1.2,3.4-Tetrahydroanthracene (50)
Selective hydrogenation of anthracene (48) to 1,2,3,4-tetrahydroanthra-
cene (50) is readily achieved through catalytic hydrogenation in the presence
4
of Rh/C or Rh/Al000 to give 50, whereas Pd/C leads to 49.
z j ~~"" •"•"•"
25
-------
SECTION 5
EXPERIMENTAL PROCEDURES33
As pointed out in Section 4, some of the synthesis steps and experimental
techniques used in preparation and purification of the hydrocarbons in this
report are known. However, new techniques and reagents generally provide some
improvement of most syntheses and where appropriate, these are presented in
this section.
Purification of Solvents
Bulk solvents (acetone, benzene, cyclohexane, ethyl ether, 95% ethyl
alcohol, ethyl acetate, isohexane, isooc£ane and toluene) were purchased from
commercial sources and redistilled from an all-glass system before use. Ethyl
ether was distilled from sodium borohydride to destroy peroxides, and then
stored over ferrous sulfate heptahydrate to inhibit their reformation. Acetic
acid was not processed.
Depending upon the need, some solvents received additional treatment. For
example, cyclohexane was repeatedly stirred with concentrated sulfuric acid
until there was no visible darkening of the sulfuric acid layer. The proc-
essed cyclohexane was then separated from the sulfuric acid layer and freed
of traces of sulfuric acid by filtering through basic alumina. The filtrate
was then redistilled. Another approach was to percolate cyclohexane, iso-
hexane, and isooctane through layers of alumina and silica gel.
Benzene was purified by refluxing with aluminum chloride, washing with
water, drying, filtering, and distilling.
26
-------
Purification of Chrysene (1). Fluoranthene (2). Pyrene (3). and 1.3,5-Tri-
phenylbenzene (4).
Hydrocarbons _1, J2, _3, and _4 were obtained from commercial sources and
their purification included use of the techniques described in Section,
pp. 6-13. Their pmr spectra are presented as Figures 6-9 respectively.
Purification of Chrysene (1)
Chrysene is commercially available and consequently direct purification
was used rather than synthesis. Commercial^ has been reported to contain
34
benzocarbozoles . and possibly other aromatic amines, which are difficult to
remove. Accordingly, 50 g of JL, which had already received a purification
2
treatment with picric acid, was placed in a Soxhlet extraction apparatus
(see Figure 2) containing a 3" layer of Kaolin coated with ferric chloride.
Chrysene was then extracted through the Kaolin layer with isohexane. As
expected, an indigo coloration developed which indicated the presence of
aromatic amlne. An 0.5% Impurity remained. This impurity was removed
through repeated recrystallization from benzene to yield 17.5 g of colorless
crystals. The final purification was then affected by sublimation, cf.
Figure 3, and a 10.6-g sample, mp 251-253°, contained in 94 vials, was sup-
plied. The purified Chrysene was not sufficiently soluble to permit obtain-
ing a conventional 100 MHz pmr spectrum, and therefore a Fourier-transform
spectrum (Figure 6) was obtained. As a consequence, spurious peaks from
solvent impurities appear in the spectrum in the nonintegrated region.
Purification of Fluoranthene (2)
Fluoranthene was routinely purified using recrystallization and picrate
2
purification techniques. Since a larger sample was required for API use as
well, zone refining was used in the final purification stage to give _2, mp
110-111°. The pmr spectrum is shown in Figure 7.
27
-------
Purification of Pyrene (3) and 1,3.5-Triphenylbenzene (4)
Tetracene is a frequently cited impurity in commercial pyrene. Accord-
ingly, we treated the impure pyrene with maleic anhydride dissolved in
36
boiling toluene to remove this Impurity. The resulting Diel's-Alder product
of tetracene shown below is then selectively removed by adsorption on basic
alumina. Pyrena is unaffected by maleic anhydride. The subsequent purifica-
tion, including recrystallizing and zone refining, gave ^, mp 155-156°.
0.
1,3,5-Triphenyl benzene (4) was purified by recrystallizing from hot iso-
propyl alcohol and then leaching with hot isooctane. It was then eluted
3
through acidic alumina, contained in a Soxhlet, with isohexane. The vacuum-
dried product melted at 174-175°. The pmr spectra of JJ and k_ are in Fig. 8
and 9 respectively.
Synthesis and Purification of Anthanthrene (5, Scheme I) Dibenzo[def,mno]-
chrysene.
Anthanthrene (5) was synthesized as shown in Scheme 1 and as described. '
Since J5 is typical of high-molecular-weight polycyclic aromatic hydrocarbons,
a description of its purification is pertinent. Crude 5_ from dehydrogenation
was eluted through a Dicalite column in a Soxhlet column (Fig. 2) with toluene
to remove catalyst. After recrystallization from toluene, no starting mater-
ial, 21, was detectable. The sample was further recrystallized from toluene
and then eluted through neutral and basic alumina columns. A picrate was
2
prepared, recrystallized from toluene, and cleaved. The final purification
37
of 5_ included recrystallizing from toluene, boiling with hot isohexane to
28
-------
remove toluene and then pumping at 0.1-mn for 2 days at room temperature, 2
days at 70° and 1 day at 120°. Anthanthrene was gold-colored and the mp was
264-265.5°. The purified 5_ was transferred to ampoules and screw-cap vials
' in a nitrogen atmosphere. The ampoules were then evacuated and sealed.
This hydrocarbon was not sufficiently soluble to obtain a satisfactory
pmr spectrum.
Synthesis and Purification of Benz[a]anthracene (6, Scheme II)
9 10
Our synthesis of J5, mp 140-142°, has been published. The final recrys-
tallization was from ethanol and the pmr spectrum is shown in Fig. 10.
Synthesis and Purification of Benzo[b]fluoranthene (7, Scheme III)
A 160-g sample of fluorene was dissolved in 1.7 1. of xylene containing
16.6 g. of KOH. To this mixture was added 140 g of freshly distilled
£-chlorobenzaldehyde and one drop of piperidene. The mixture was heated to
reflux with stirring and the water that evolved from the reaction was col-
lected in a Dean-Stark trap. After the formation of water ceased, the
reaction mixture was cooled, poured into water, and extracted with toluene.
The extract was washed with dilute HC1, water, aqueous sodium carbonate, and
again with water. After drying (MgSO,) and filtering, toluene and xylene
were removed by vacuum-distillation to give 263 g (91%) of an orange oil
consisting mainly of 24. This oil was used in the cyclization reaction
without purification. The preparation of j^4 was repeated several times with
different amounts of starting materials. One run was made using N-phenyl-
trimethylammonium hydroxide as the basic catalyst. The yield from this run
approximated that of the other runs.
To cycllze 24. 352 g (1.2 mol) was mixed with 1 1. of technical grade
quinoline and 141 g of KOH. This mixture was heated under a nitrogen
atmosphere at reflux temperature for 2 hr. Water evolved from the reaction
29
-------
and was collected In a Dean-Stark trap. When water no longer formed, the
reaction mixture was cooled and acidified with 4 1. of cone. HC1. The solu-
tion was extracted with benzene (3x31.) and the combined benzene layers
were washed with water. This extract was passed through basic alumina 3
times to remove black tarry impurities. The red filtrate was then concen-
trated to 237 g. (78%) of orange solid containing ]_. After two recrystal-
lizations from ethanol and one from benzene, 7. was obtained as a faint
yellow solid. The yield at this point was 50%. Further purification
yielded a white solid with a faint yellow tint, mp 167° to 168° [lit.13
167°]; ir spectrum (KBr) 890, 772, 737, 731 cm'1; mass spectrum (70 eV) m/e
(rel intensity) 252, M+ (100), 251 (06), 250 (17), 248 (05), 126 (15), 125
(09).
Synthesis and Purification of cis>anti-4,5,6,6a,6b,7,8,12b-0ctahydrobenzo-
[j]-fluoranthene (27, Scheme IV) and Benzo[j]fluoranthene (8, Scheme IV).
1-Tetralone was reduced to 1-tetralol by treatment with 4.4 equivalents
of diisobutylaluminum hydride in toluene solvent. After all of the 1-tetra-
lone had been added to the reducing agent, the mixture was stirred for an
additional 0.5 hr. Ethyl acetate was added to decompose the excess reducing
agent. The reaction mixture was then cautiously poured on ice containing
cone. HC1. This addition was done cautiously, since there is considerable
evolution of isobutane and frothing can cause loss of material. The acidi-
fied reaction product was then transferred to a separatory funnel and the
toluene layer was washed with water, a saturated solution of sodium carbon-
ate, and then again with water. The extract was filtered through solid
sodium carbonate, dried (MgSO^), filtered, and concentrated by rotary evap-
oration under vacuum to yield 86% of crude 1-tetralol.
30
-------
Tetralol (516 g) was dehydrated by steam distillation from 20 g of
oxalic acid. The steam condensate and the dihydronaphthalene were separated;
the organic material was dried (MgSO.) and distilled at 70° (0.8 mm) to
yield 80% (362 g, 2.8 mol) of 1,2-dihydronaphthalene.
1,2-Dihydronaphthalene (108 g, 0.83 mol) in a 1-1. fluted flask equipped
with mechanical stirrer and condenser containing 500 ml of benzene and 20 g
of A-15 resin was heated at reflux for 25 hr. The solution was cooled, fil-
tered to remove resin and concentrated by rotary evaporation. The residue
was distilled in a Kugelrohr apparatus at 170° (1 mm) and yielded 77 g of
38
crude dimer consisting of a mixture of 25, 26, and 27. Crystallization
from an ether:isohexane mixture (1:1) gave 18 g of colorless crystals, mp
85-88°, consisting mainly of 27. Recrystallization of this product from
ether and also from acetone gave colorless crystals of 27, mp 92-93° [lit.
93°]; mass spectrum (70 eV) m/e (rel intensity) 260 (100), 259 (31), 232
(44), 217 (35), 169 (61), 78 (44).
The mother liquor remaining from the purification of 2]_ and the other
components of the original cyclization mixture were dehydrogenated by heat-
in the presence of 10% Pd/C under a nitrogen atmosphere for 3 hr at 230°.
The reaction mixture was then cooled to 100° and toluene was added. The
reaction mixture was then cooled to room temperature and filtered through
Dicalite to remove catalyst. After concentration by rotary evaporation,
the brown residue was triturated with isohexane to give yellow crystals of
J3 mixed with 28. Our attempts to separate j} and JJ8 were not successful,
and therefore we repeated the dehydrogenation, using material which did not
contain 25. This latter dehydrogenation gave bright yellow crystals of JJ
in practially quantitative yield and free of 28. The purification of JJ
4
was accomplished through use of a picric, acid column.
31
-------
The final purification of _8 involved elution through alumina with iso-
hexane, concentration to remove solvent, recrystallization from ethanol and
sublimation at 90° (0.1 mm), to give JJ, mp 164-165°; mass spectrum (70 eV)
m/e (rel intensity) 252 (100), 251 (7), 250 (20), 126 (7), 57 (8), 43 (8).
Synthesis and Purification of Benzo[k]fluoranthene (9, Seheme V)
A solution of acenaphthenequinone (72.5 g, 0.4 mol) jo-phenylenediaceto-
nitrile (67 g, 0.43 mol), and 1100 ml of piperidine was placed in an ice
bath for 50 min without stirring, stirring for 40 min at ice bath tempera-
ture and then stirring for 4 hr at ambient temperature. After 65 hr, the
reaction mixture was treated with 8.6 1. of 5% hydrochloric acid and fil-
tered. The filter cake was washed with water, recrystallized from nitro-
benzene, and leached with isohexane to yield 88.5 g (73.6%) of 7,12-dicyano-
benzo[k]fluoranthene (29): mp 357-359°.
A mixture of 30 g (0.1 mol) of J9 and 3000 g of 100% phosphoric acid was
stirred for 21 hr at room temperature, heated to 280° for 18 hr and then
cooled to room temperature. The reaction mixture was then poured into 2 1.
of water, stirred overnight, and extracted with benzene. The benzene extract
was concentrated, the resulting yellow solid was collected by filtration,
placed in a Soxhlet apparatus over a bed of alumina and then extracted with
3
isohexane. The isohexane solution was concentrated, yielding 20.5 g (81.3%)
of j»: mp 217-217.3° [lit.17 217-217.4°]; mass spectrum (70 eV) m/e (rel
intensity) 253 [(M+ 1)+ 6], 252 (100), 126 (4), 113 (1), 58 (1).
Synthesis and Purification of Benzo[ghi]perylene (10. Scheme VI)
19
The synthesis of 3.0 is an adaptation of a published procedure.
The diol and the corresponding dlene shown in Scheme j6 were prepared as
32
-------
follows: 1-Tetralone (146 g, 1.0 mol) and 5.1 g of mercuric chloride were
added to a 3-1., 2-neck, round-bottom flask (equipped with nitrogen inlet,
reflux condenser, magnetic stirring, and heating mantle) containing 1400 ml
of anhydrous benzene, 100 ml of anhydrous ethanol and 51.4 g (2 g. atom) of
aluminum foil. The system was flushed with nitrogen and then brought to
reflux. After 20 hr, the liquid contents were decanted and washed twice with
cold 10% HC1, and then with water. The organic phase was dried (MgSO,)„
filtered, and concentrated through rotary evaporation. The resulting diol
was then dissolved in a mixture of 300 ml of acetic acid and 300 ml of acetic
anhydride. This solution was heated at reflux for 5 hr and then concentrated
under vacuum to give 88 g (68%) of the diene, mp 135-137.5°, shown in Scheme
VI.
The diene product from above was then treated with 10 molar equivalents
of maleic anhydride at 120° for 8 hr, to give the Diels-Alder product shown
in Scheme VI. This adduct was Isolated by dissolving the cooled reaction
mixture in hot acetic acid, from which it crystallized to give 163 g
(84%) of material, mp 234-252°.
The conversion of this Diels-Alder product to 10 was accomplished by
heating 3.57 g (0.10 mol) at 265° for 13 hr in the presence of 0.8 g of
10% Pd/C in a stream of nitrogen. Heating was discontinued at this time
because C0~ could no longer be detected in the effluent nitrogen. Purifi-
cation of 10 was accomplished by elution from basic alumina in a Soxhlet
3
extractor with hot benzene. This procedure yielded 2.24 g (80.5%) of 10.
Recrystallization from benzene and sublimation at 260° (0.02 mm) gave puri-
fied JLO as yellow crystals, mp 276-277°C [lit.19 273°]. Further handling
during filling of vials was done in an argon atmosphere.
33
-------
Synthesis and Purification of Benzo[a]pyrene (11. Scheme VII)
21
The synthesis shown in Scheme VII follows a reported route. In
repeating this synthesis, we experienced difficulty in the conversion of ^2
to J3 as well as JJ3 to 34, since procedures used previously failed to give
satisfactory results. From this work we have selected the following. A
sample (25 g, 0.09 mol) of the keto acid 32. red phosphorus (11 g), 57% HI
(20 ml), and acetic acid (400 ml) were heated under a nitrogen atmosphere
for 96 hr. The warm reaction mixture was filtered and then diluted with
water (1.5 1.), whereupon acid ^3 separated as a solid precipitate. This
solid was collected by filtration, washed with 1 1. of water and then dis-
solved in 200 ml of saturated sodium bicarbonate solution. The solution
was filtered and reprecipitated by acidification with 10% HC1. Recrystal-
lization from toluene-isohexane gave 17 g (0.07 mol, 72%) of colorless
plates of _33, mp 187-188°C [lit.21 187-188°C]; ir (KBr) cm"1 3010, 2940,
1690, 1460, 1430, 1335, 1320, 1275, 1210, 910, 820, 755, 725, and 710; mass
spectrum (70 eV) m/e (rel intensity) 288 (M+, 30), 228 (16), 227 (17), 216
(20), 215 (100), and 213 (23); pmr (DMSO-d,) 5 8.49-7.94 (m, 9, ArH), 3.38
o
(t, 2, ArCH2, J=7 Hz), 2.44 (t, 2, CH2C02H, J-& Hz), and 2.05 (pentet, 2,
ArCH-CH0, J=7 Hz).
i. ~"£.
The acid _33 (25 g, 0.09 mol) was cyclized to ketone ^34 by adding small
portions over a 30-min. period to 200 g (10 mol) of anhydrous liquid HF
contained in polyethylene bottle. During the addition, the bottle was
cooled in ice. After a few min., ice was removed and nitrogen was swept
through the sample to evaporate HF, which was trapped by bubbling through
water and then alkali. After the HF had evaporated, the product mixture was
broken up and triturated with saturated K-CO- and then filtered. The filter
34
-------
cake (22 g, 0.80 mol) was then purified by extraction with ethanol in a
Soxhlet apparatus containing 100 g of neutral alumina. The ethanol extract
yielded 86% (20 g, 0.07 mol) of ketone JJ4 as shiny yellow plates, mp 171-173°C
21
[lit. 170-173°C]. The ketone ^4 was converted to benzo[ji]pyrene (11) by
reducing to the alcohol 35, dehydrating and then dehydrogenating. These
steps were as follows: the ketone J4 (27 g, 0.1 mol) was dissolved in 1 1.
of toluene and then added to a solution of 23 g (0.15 mol) of diisobutyl-
aluminum hydride in 500 ml of toluene. During the addition the temperature
was held below 50°. The excess reducing agent was consumed with 10 ml of
ethyl acetate. The reaction mixture was then cooled and poured onto 2 kg of
ice containing 250 ml of cone. HC1. The toluene layer was separated, washed
with sodium bicarbonate solution and then with water. It was next dried
(MgSO,), filtered, and concentrated, to give a pale brown solid (25 g, 0.09
mol, 90%). This product was a mixture of the alcohol ^5 and the corres-
ponding alkene. Our efforts to prepare pure 35 were not successful. The
crude alcohol 35 (10 g, 0.04 mol) was then dehydrated in a mixture of acetic
acid (500 ml) and cone. HC1 (0.5 ml) by heating at reflux for 5 min. The
reaction mixture was then filtered, poured into ice water, whereupon pale
yellow crystals of the alkene separated (8.2 g, 0.03 mol, 86%), mp 143-146°.
37
This product was recrystallized from isohexane to give 7.5 g (0.03 mol) of
pale yellow plates, mp 148-149° [lit.21 148-149°].
The purified alkene (18 g, 0.07 mol) was mixed with 1.8 g of 10% Pd/C
and then heated in a stream of nitrogen at 320-330° for 2 hr. The flask was
allowed to cool and the contents, including material which had sublimed into
the neck of the flask, were transferred with hot benzene to a Soxhlet appar-
3
atus containing 80 g of neutral alumina. Extraction with benzene and con-
centration under vacuum gave a 96% yield (17 g, 0.07 mol) of crude 11. This
35
-------
3
material was then extracted through 100 g of neutral alumina with isohexane
to give 14 g (0.06 mol) of 11, mp 177-178°. Additional purification was
accomplished by recrystallizing from toluene-isohexane. The melting point
of the sublimed product was found to be 177.5-178° ]lit.21 176.5-177°]. The
yield of the final product was 60% (11 g, 0.04 mol).
Syntheses of Coronene (12, Scheme VIII), Indeno[l,2,3-cd]pyrene (13, Scheme
IX), and Perylene (14, Scheme X).
Hydrocarbons 12, 13, and 14 are currently being synthesized as shown in
Schemes VIII, IX, and X respectively.
Synthesis and Purification of Triphenylene (15, Scheme XI) and s-Dodecahydro-
tripheriylene (40, Scheme XI)
Distilled cyclohexanone (850 g) was placed in a 2-1., round-bottomed
flask fitted with a mechanical stirrer. Sodium hydroxide flakes (85 g) was
added and the mixture was stirred for 72 hr. During this time the mixture
turned from colorless to yellow to white with the formation of a solid prod-
uct. When the reaction was stopped, the mixture was poured over 2 kg of Ice
and then stirred. The product (300 g) was filtered off. The filtrate con-
taining unreacted cyclohexanone was extracted with petroleum ether and the
organic layer, after separation, was washed with water and dried (MgSO.) and
I
filtered. Evaporation of the solvent yielded about 400 g of unreacted cyclo-
hexanone. Yield of trimeric product was 35% (67% based on recovered cyclo-
hexanone) . Repetition in a nitrogen atmosphere caused no significant
increase in the yield. A cleaner product was obtained when the crude reac-
tion mixture was diluted with ethanol and water and then filtered. The
recovery of the unreacted cyclohexanone, however, was more difficult in this
case. The crude product (mp 175-188°) was recrystallized from isopropyl
alcohol to give crystals of trlmer; mp 181-185° (lit.28a 175°; lit.28b 210°);
36
-------
mass spectrum m/e (rel intensity) 294 (M+, 4), 258 (91), 215 (142), 131
(96), 77 (125), 55 (111); ir (KBr) 3220, 2920, 2850, 1440, 1225, 1093, 950,
and 825 cm" .
The cyclohexanone trimer (50 g) was dissolved in 500 ml of pyridine in
a 1-1., round-bottomed flask. Benzoyl chloride (50 ml) was added and the
mixture stirred at 80°C for one hr using a magnetic stirrer. The clear
brown solution was cooled and then poured into 1 1. of water and the solu-
tion acidified with concentrated HC1. The product was then extracted with
benzene three times and the combined benzene extracts were washed with
sodium bicarbonate solution and then with water. After drying (MgSO.) and
filtering, the solvent was evaporated to a brown oil (44 g, theoretical
yield). This oil was used in the next step without purification. Other
acidic reagents (p_-toluenesulfonyl chloride and A-15) were equally effective.
A 44-g sample of dehydrated material (prepared using benzoyl chloride in
pyridine) was heated in a fused salt bath at 350°C under nitrogen for 90 min.
Water was eliminated. The flask was cooled, the solidified mass was then
washed with small amounts of methanol in order to remove unreacted material.
The residue, weighing 39 g (89% yield) was passed through alumina and 56.5
g (89% yield) of a white crystalline dodecahydrotriphenylene (40); mp
228-230°C (lit.28a 232°); mass spectrum (70 eV) m/e (rel intensity) 240
(M+, 1641), 212 (538), 211 (401), 199 (497), 198 (572), and 183 (430); pmr
(CDC13) 6 1.60-1.96 (broad singlet, all nonbenzylic protons) and 6 2.38-2.74
(broad singlet, all benzylic protons).
The crude 40 was passed through alumina in a Soxhlet column using iso-
hexane as the refluxing solvent. Following this, the material was recrystal-
lized three times from benzene-isohexane mixture. This procedure removed
37
-------
traces of oily Impurities resulting from the pyrolysis. Some solvent was
retained in the crystals, even after extensive pumping. The compound was
found to be devoid of detectable impurities (by glc) at this stage. A final
sublimation procedure was adopted in order to remove the solvent and to
improve the purity of the compound. A special apparatus shown in Fig. 3 was
constructed for this purpose.
The sublimed compound condensed on the stem above the level of the
fused salt. When the major portion of the compound had sublimed, the mater-
ial was scraped out and sealed in oven-baked, previously weighed vials.
Combustion calorimity by the Thermodynamics Research Group at the
Bartlesville ERBA station showed 40 to be 99.987%.
A 15-g sample of ^0 and 1.5 g of 10% Pd/C were heated in a round-
bottomed flask immersed in a fused sodium nitrite-sodium nitrate bath.
Hydrogen gas started bubbling out (attached bubble tube) when the temperature
reached 300°C. The flask was heated at this temperature for two hours until
no more hydrogen evolved. The flask was cooled and the hard residue was dis-
solved in benzene and the suspended Pd/C catalyst was removed by filtering
through Dicalite. Evaporation of the solvent gave a quantitative yield of
15. The course of the reaction could be followed by glc which showed the
starting material giving rise to three other peaks and one of the peaks
remaining at the end of the reaction. Attempts to stop the reaction after
the formation of a partly aromatized product were unsuccessful, since the
reaction always yielded a mixture of products, the ratio varying with time.
Crude J3, obtained by dehydrogenation of 40, was almost free of starting
material and any of the partly dehydrogenated products. Hydrocarbon 15 was
further purified by Soxhlet extraction through alumina, recrystallization
from benzene-isohexane, and picrate formation and recrystallization followed
38
-------
2
by decomposition of the picrate. The final step was sublimation to remove
trapped solvent. This gave colorless J.5:30 mp 195-197°C (lit.28c 199°C);
mass spectrum (70 eV) m/e (rel intensity) 229 [(M+ 1)+, 818], 228 (M+,
3878), 227 (435), 114 (443), 113 (496), and 112 (214); pmr (CDC13) 6 7.54-
7,74 (multiplet protons) on C-l, C-4, C-5, C-8, C-9, C-12), 8.54-8.74
(multiplet protons on C-2, C-3, C-6, C-7, C-10, C-ll.)
18
Synthesis and Purification of Benzo[c]phenanthrene (44, Scheme XII)
A solution of 1-tetralone (505 g, 3.46 mol) and 500 ml of anhydrous
ether was added to an ether solution of 5.1 mol of phenyl magnesium bromide
at such a rate as to maintain reflux. After addition, reflux was maintained
for 1 hr. The reaction mixture was then poured onto an excess of ice cold
10% hydrochloric acid and then steam distilled to remove volatile materials.
The pot residue was extracted with ether, the ether extract was concentrated
and the resulting liquid was dissolved in 1 1. of benzene containing 5 g of
oxalic acid. Water was removed by azeotropic distillation. The benzene
solution was concentrated, passed through basic alumina, and vacuum-distilled
to yield 445 g (62%) of l-phenyl-3,4-dihydronaphthalene (41); bp 135-140°
(2 mm); ir (neat) 3.37, 3.48, 3.60, 6.00, 6.31, 6.79, 7.00, 7.61, 7.8:, 8.71S
9.109 9.39S 9.82, 10.56, 11.14, 12.21, 13.08, 13.27, 13.64, and 14.39 P, nmr
(CDC13, TMS) 6 7.60-6.94 (m, 9, ArH), 6.14-5.92 (t, 1, C=CH), 2.78-2.10 (m,
4B CH2)o
A 93-g (0.5-mol) sample of _41 and maleic anhydride (233 g, 2.38 mol)
were mixed and heated to 190° for 19 hr. The resulting oil solidified and
was recrystallized from acetic acid yielding 73 g (50%) of the bis
Diels-Alder adduct ^2: mp 315-316° {lit.31 315-316°]; ir (KBr) 3.34, 3.51,
5o909 6.19, 6.46, 7.02, 8.00, 8.24, 10.95, 11.68, and 12.91 .
39
-------
The Diels-Alder adduct 4,2 (100 g, 0.34 mol) was mixed with 5 g of 5%
Pd/C in 1000 ml of 2-methylnaphthalene and then heated at reflux for 8 hr.
The 2-methylnaphthalene was vacuum-distilled and the resulting solid was
3
extracted in a Soxhlet apparatus with benzene to yield 74.9 g (95%) of
benzo[3,4]phenanthrene-l,2-dicarboxylic acid anhydride (43); mp 249-251°
[lit.31 257-258°]; ir (KBr) 5.52, 5.78, 6.79, 7.16, 7.59, 7.91, 8.42, 8.80,
11.11, 11.39, 12.00, 12.42, 12.69, and 13.43 v.
A mixture of cuprous oxide (1.52 g, 0.011 mol),^3 (3.18 g, 0.11 mol),
and 50 ml of quinoline was refluxed under nitrogen for 4 hr, cooled, and
poured into 500 ml of 10% hydrochloric acid, and extracted with ether. The
ether solution was concentrated, dissolved in benzene, passed through basic
alumina, and the benzene solution concentrated to yield 1.8 g (72%) of
benzo[cjphenanthrene (44); mp 67.5-68°; ir (KBr) 3.41, 7.20, 8.32, 9.85,
10.73, 11.62, 12.20, 12.50, 13.73, and 15.35 y; nmr (CDC13,TMS) 5 9.16-9.01
(m, 2, peri-H), 8.00-7.50 (m, 10, ArH).
Synthesis of Tetrahydropyrene (46), Hexahydropyrene (47), and 1,2,3,4-
Tetrahydroanthracene (50)
Hydrocarbons 46» 47, and 50 are currently being synthesized as shown in
Scheme XIII and XIV.
40
-------
-!-, 1 . ' ,—I '
5000
2SOO
1C 90
S<0
—v. --" -—' ——j ^
I I
Figure 6. PMR Fourier transform spectrum of chrysene (_1) in CDC1« at 100 MHz. Peaks
in nonintegrated portion result from solvent impurities.
-------
ro
Figure 7. Proton magnetic spectrum of fluoranthene (2_) at 100 MHz in CDC1.,.
-------
I 1 I
• i r
2900
80
no
i
U)
-! T~
w
Figure 8. Proton Magnetic spectrum of pyrene (3) at 100 MHz in CDClj.
-------
Figure 9. Proton magnetic spectrum of 1,3,5-triphenylbenzene (£) at 100 MHz in
-------
Ln
Figure 10. Proton magnetic spectrum of benz[a]anthracene (6) at 100 MHz in CDC1_.
-------
5000
1000
I
MO
wo
so
V
Figure 11. Proton magnetic spectrum of benzo[_b]fluoranthene (_7) at 100 MHz in CDC1,. Peaks in
the nonaromatic portion of the spectrum result from solvent impurities.
-------
Figure 12. Proton magnetic spectrum of benzo[jjfluoranthene (8) at 100 MHz in CDC1,.
-------
;:..;::-; .t:.1.
oo
Figure 13. Proton magnetic spectrum of benzo[k.]fluoranthene (9) at 100 MHz in acetonitrile. Peaks
in the nonaromatic portion of the spectrum are of the solvent and solvent impurities.
-------
-I 8 !_
I I ' I ' T
I I I ' I I
i • • i i —r
vo
f
so
JL
T~
I
' I
_l I 1_
14. PMR Fourier transform spectrum of benzo[ghi]perylene (10) in CDCl, at 100 MHz. Peaks
in the region 0-6 ppm are due to solvent impurities.
-------
Figure 15. Proton magnetic spectrum of benzo[a]pyrene (11) at 100 MHz in CDCl-.
-------
T
no
100
(9
15
Figure 16. Proton ^ ^aetic spectrum of triphenylene (15) at 100 MHz in CDC1-.
3
-------
_i i i
ro
1COO
500
2!
25
-) r
PPM
~t
I . - I I ,. . . I 1
~i r
Figure 17. Proton magnetic spectrum of benzo[c_]phenanthrene (44) at 100 MHz in CDC1_.
-------
CO
• i • • • • i • . - . i • . • • i • • • . i ..-,... ,....,. ........
Figure 18. Proton magnetic spectrum of cis,anti-4,5,6,6a,6b,7,8,12b-octahydrobenzo[Jj fluoranthene (27)
at 100 MHz in CDC1.J.
-------
"r
tooo
I
600
40
Figure 19. Proton magnetic sn- <~trum of ^-dodecahydrotriphenylene (40) at 100 MHz in CDC1.,.
-------
SECTION 6
RESULTS AND DISCUSSION
The objective of this project was to synthesize and purify PNA compounds,
chiefly hydrocarbons, of interest to the Chemistry and Physics Laboratory,
NSHC, Research Triangle Park.
In Sections 4 and 5, we presented the synthesis routes and the purifi-
cation techniques used in obtaining the pure samples. To avoid duplication
and to foster better understanding of how the syntheses were undertaken and
how the results were achieved, we commented on failures as well as successes
at the time the material was presented in Section 4. However, experimental
details of unsuccessful work was omitted in Section 5.
The reader specifically interested in the status of hydrocarbons supplied
to the EPA is referred to pp. 1, 6, 14-22, and 23, which show the hydro-
carbons obtained by purification of commercial material, those synthesized,
the amounts provided and which compounds remain to be synthesized.
Our preparation of the hydrocarbons listed in Section 4 resulted in
new approaches to synthesis and purification. These findings have been cited
QV
::n our Quarterly Reports, described in the theses of Dr. L. L. Ansell,
9 14
Mr. F. U. Ahmed, and Mr. A. R. Taylor, and some of this work has been
published as reported in the List of Theses and Publications (p. 60).
The salient features of this work was brought out in Sections
4 and 5. Further, as has been customary in our earlier work for the
American Petroleum Institute, we have continued to provide data on the
55
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properties of our hydrocarbons and selected intermedaites to the scientific
community through the Data Distribution office of the API and TRC located
at Texas A&M University, College Station, Texas. The selfless efforts of
Mr. M. C. Hamming and Dr. G. W. Keen, and more recently Mr. A. R. Taylor,
of the Analytical Research Section of Continental Oil Company in obtaining
the spectra, and the generosity of the Continental Oil Company, Research
and Development, in sharing the data, made these contributions possible.
Some data has also become available from the publications of the Energy
Relations Research Group of the U. S. Energy Research Center at Bartlesville
Okla. This group was directed by Dr. D. R. Douslin and now by Mr. W. D. Good.
Since the samples from this work were highly purified, we decided to
include pmr spectra of the completed hydrocarbons as part of this report*
The pmr spectrum of anthanthrene (5), however, was not included because
its insolubility precluded an acceptable pmr spectrum. These spectra are
shown on pp. 41-54.
56
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FOOTNOTES AND REFERENCES
13
1. E. J. Eisenbraun and L. P. Varga. The Role of C-Organic Molecules in
Pollution Studies. Pollution Technol. Int., 6_, 34 (1972).
2. E. J. Eisenbraun, T. E. Webb, J. W. Brunham, and L. E. Harris. An
Efficient Technique for the Cleavage of Hydrocarbon Picrates. The Puri-
fication of 1,8-, 2,6-, and 2,7-Dimethylnaphthalene. Org. Prep. Proc.
Int., ^, 249 (1971).
3. C. E. Browne, W. L. Buchanan, and E. J. Eisenbraun. An Improved Soxhlet
Apparatus. Chem. Ind. (London), 35 (1977).
4. K. D. Cowan, L. L. Ansell and E. J. Eisenbraun. Separation of Anthracene
Hydrogenation Products on a Picric Acid Column. Chem. Ind. (London),
957 (1976).
5. K. D. Cowan and E. J. Eisenbraun. Soxhlet Extraction as a Safety Feature
in the Synthesis of Polynuclear Aromatic Hydrocarbons. Chem. Ind.
(London), 46 (1975).
6. L. L. Ansell and E. J. Eisenbraun. An Apparatus and Procedure to Clean
Sintered-Disc Buchner Funnels. Chem. Ind. (London), 44 (1975).
7. R. Scholl and K. Meyer. Ber., 67b. 1229 (1934).
8. a) L. L. Ansell, T. Rangarajan, W. M. Burgess, E. J. Eisenbraun, G. W.
Keen and M. C. Hamming. Org. Prep. Proc. Int., J5, 133 (1976).
b) L. L. Ansell, Ph.D. Thesis, Oklahoma State University, 1976, 63
9. F. U. Ahmed, M. S. Thesis, Oklahoma State University, 1975, 60 pp.
Ci
10. ff. U. Ahmed, T. Rangarajan, E. J. Eisenbraun, G. W. Keen, and M. C.
Hamming. Org. Prep. Proc. Int., 7_, 267 (1975).
11. P. H. Groggins and H. P. Newton. Ind. Eng. Chem., _22, 157 (1930).
12. H. R. Snyder and F. X. Werber. J. Am. Chem. Soc., 72_, 2965 (1950).
13. E. Clar. Polycyclic Hydrocarbons, Vol. 2, Academic Press, New York, 1964.
14. A. R. Taylor, M. S. Thesis, Oklahoma State University, 1974, 73 pp.
57
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15. D. V. Hertzler, E. J. Eisenbraun, and P.W.K. Flanagan. Chem. Ind.
(London), 877 (1969).
16. Unpublished work of T. K..Dobbs, of these laboratories.
17. M. Orchin and L. Reggel. J. Am. Chem. Soc., 73, 436 (1951).
18. Unpublished work of E. H. Vickery, of these laboratories.
19. Y. Altman and D. Ginsburg, J. Chem. Soc., 466 (1959).
20. Unpublished work of C. E. Browne, of these laboratories.
21. L. M. Fieser and Mary Fieser, J. Am. Chem. Soc., 57., 782 (1935).
22. Unpublished work of T. Rangarajan, of these laboratories.
23. Unpublished work of L. L. Ansell, of these laboratories.
24. Unpublished work of A. G. Holba, of these laboratories.
25. Unpublished work of N. R. Seller, of these laboratories.
26. I. M. Aigken and D. H. Reid, J. Chem. Soc., 3487 (1956).
27. F. A. Mason, Ind. Chemist, 137 (1929).
28. a) S. V. Svetozarskii, E. W. Zil'berman, and G. A. Razuvaev, Zhur.
Obshchei Khim., 29_, 1454 (1959).
b) P. Rollin and R. Setton, C. R. Acad. Sci., Paris, Ser. C. 263 (18),
1080, 1966 (Fr.).
c) C. M. Buess and D. D. Lawson, Chem. Rev., 60, 313 (1960).
29. Unpublished work of P. Vuppalapaty, of these laboratories.
30. The preparation of hydrocarbons 15 and 40 was jointly sponsored by EPA
and API. We thank the Thermodynamics Research Group of the U.S. ERDA
Center at Bartlesville, Oklahoma, for informing us that combustion calori-
metry showed the percent carbon of 15 and 40_ to be 99.99 t 0.005% and
99.99 ± 0.003% respectively.
31. J. Szmuskovisz and E. J. Modest, J. Am. Chem. Soc., 70. 2542 (1948).
32. Unpublished work of K. D. Cowan, of these laboratories.
33. a) Gas chromatographic analyses were carried out with a Hewlett-Packard
Model 5750B instrument equipped with dual-flame ionization detection
using 0.25-in. or 0.125-in. x 10-ft columns filled with 80-100 mesh
Chromosorfa G (acid-washed and DMCS-treated) coated with 5% silicone
rubber UC W-98. 1.5% OV-17 + 2% QF-1 on Chrom. Q 80-100 mesh was
also used as a column packing.
58
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b) Nuclear magnetic resonance spectra were obtained from a Varian
XL-100 spectrometer.
c) Mass spectra were obtained from a Consolidated Electrodynamics
spectrometer operated under low and high resolution conditions.
d) Pd/C and Rh/C catalysts were obtained from commercial sources.
e) Phillips Chemical Company, isohexane bp 55-60°.
34. We thank James E. Meeker for calling this to our attention.
35. D. M. Jewell and J. W. Hunger, J. Heterocycl. Chem., 8., 333 (1971).
36. 0. C. Dermer and J. King., J. Am. Chem. Soc., 63, 3232 (1941).
59
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LIST OF THESES AND PUBLICATIONS
Theses
A. R. Taylor, "I. Synthesis of l,l,3-Trimethyl-3-Phenylindan and the
Synthesis and Chemistry of l-Methyl-3-Phenylindan and the Corresponding
Indenes. II. Synthesis and Purification of Fulvenes and BenzofbJfluor-
anthene," M.S. Thesis, Oklahoma State University, 1974, 73 pp.
F. U. Ahmed, "I. Synthesis and Purification of Benz[aJanthracene.
II. Friedel-Crafts Reaction Applied to Aromatic Ethers and Crotonic
Acid," M.S. Thesis, Oklahoma State University, 1975, 60 pp.
L. L. Ansell, "I. Synthesis of 4-, 5-, and 6-Ring Polynuclear Aromatic
Hydrocarbons. II. Sodium-Amine Reactions of Naphthalenes: Cyclodimeri-
zation and Reductive Cyclodimerization," Ph.D. Thesis, Oklahoma State
University, 1976, 63 pp.
Publications
L. L. Ansell and E. J. Eisenbraun, "An Apparatus and Procedure to Clean
Sintered-Disc Buchner Funnels," Chem. Ind. (London), 44 (1975).
K. D. Cowan and E. J. Eisenbraun, "Soxhlet Extraction as a Safety Feature
in the Synthesis of Polynuclear Aromatic Hydrocarbons," Chem. Ind.
(London), 46 (1975).
F. U. Ahmed, T. Rangarajan, E. J. Eisenbraun, G. W. Keen, and M. C.
Hamming, "The Synthesis of Benz[a]anthracene," Org. Prep. Proc. Int.,
I, 267 (1975).
L. L. Ansell, T. Rangarajan, W. M. Burgess, E. J. Eisenbraun, G. W. Keen,
and M. C. Hamming, "The Synth-sis of 1,2,3,7,8,9-Hexahydrodibenzo[def,mno]-
chrysene and the Use of Hydriodic Acid-red Phosphorous in the Deoxygenation
of Ketones," Org. Prep. Proc. Int., £, 133 (1976).
K. D. Cowan, L. L. Ansell, and E. J. Eisenbraun, "Separation of Anthracene
Hydrogenation Products on a Picric Acid Column," Chem. Ind. (London), 957
(1976).
C. E. Browne, W. L. Buchanan, and E. J. Eisenbraun, "An Improved Soxhlet
Apparatus," Chem. Ind. (London), 35 (1977).
60
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA-600/2-78-006
2.
3. RECIPIENT'S ACCESSIOf*NO.
4. TITLE AND SUBTITLE
HIGH PURITY PNA HYDROCARBONS AND OTHER AROMATIC
COMPOUNDS
Synthesis and Purification
5. REPORT DATE
JJanuarv 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
E. J. Eisenbraun
8. PERFORMING ORGANIZATION F.EPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Chemistry
Oklahoma State University
Stillwater, Oklahoma 74074
10. PROGRAM ELEMENT NO.
1AD605 BE-04(FY-77)
11. CONTRACT/GRANT NO.
803097
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Sciences Research Laboratory - RTP, NC
Office of Research and Development
U. S. Environmental Protection Agency
Research Triangle Park. NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final 5-74 to 5-77
14. SPONSORING AGENCY CODE
EPA-600/09
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The synthesis and/or purification of a group of polynuclear aromatic (PNA)
hydrocarbons commonly found as pollutants in the environment are described. The
steps used in a given synthesis, the experiments carried out, and a presentation
of some instrumental data obtained in establishing the identity and purity of the
hydrocarbons are included. Publications derived from this work are cited.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
*Air pollution
Mromatic polycyclic hydrocarbons
^Chemical reactions
*Purification
13B
07C
07D
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
70
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
61
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