1924
ANALYTICAL CHEMISTRY
water in the system produces appreciable changes in the relative intensity and location of the ultraviolet peaks. The presence of a peak near 310 mp in alkaline solutions of estrogens has previously been reported by Pedersen-Bjergaard and Schou ( 8 ) ,Hamburger ( 6 ) ,and Callow (S), and attributed by the last to the formation of a phenoxy salt in ring A. The peak a t 250 mp has not previously been reported, to the authors' knowledge, although Hamburger's curves show a continuous increase in absorbance as the wave length decreased to 250 mw, ACKNOWLEDGMENT
The steroids used in the study were kindly supplied by Merck & Co., Inc., Upjohn Co., G. D. Searle and Co., Schering Corp., Sloan-Kettering Institute, Andre Sfeyer, Worcester Foundation
for Biological Research, and John J. Schneider, Jefferson Medical School. LITERATURE CITED
(1) Abelson, D., Bondy, P. K., Arch. Bwchem. and Biophys., 57, 208
(1955). (2) Bush, I. E., Biochem. J . 50, 370 (1952). (3) Callow, R. K., Ibid., 30, 907 (1936). (4) Cross, J. RI., Eisen, H. E , Kedersha, R. G., -4x.4~.CHEX.24, 1049 (1952). (5) Dorfman, L., Chem. Reus. 53, 47 (1953). (6) Hamburger, C., Acta Physiol. Latinoamer 3, 109 (1953). (7) hleyer, A., J . Org. Chem. 20, 1240 (1955). (8) Pedersen-Bjergaard, K., Schou, -4 S., Quart. J . Phnrmacol. 8 , 669 (1935). RECEIVED for review December 17, 1955. Accepted June 22, 1956. Kork supported b y Research Grant -4 254(C3) from the National Institutes of Arthritis and Metabolic Diseases, National Institutes of Health, U. S. Public Health Service.
Hydrocarbons in the 126" to 132" C. Fraction of Petroleum M O R T O N B. EPSTEIN', C H A R L E S B. WILLINGHAM2, BEVERIDGE 1. M A I R ,
and
FREDERICK D. ROSSlNl
Carnegie lnstitute of Technology, Pittsburgh 13, Pa.
Seven hydrocarbons were found in the fraction of petroleum normally boiling between 126" and 232" C., which constitutes approximately 0.68% by volume of the representative petroleum that has been under investigation for many pears by the API Research Project 6. These compounds were concentrated by extended use of the fractionating processes of distillation (both regular and azeotropic) and adsorption. The cornpounds were identified by infrared and mass spectrometric examination, coupled with measurements of the simple physical properties. The names and estimated relative amounts of the seven compounds in this fraction of petroleum, given in decreasing order of quantity, 1-trans-2-cis-3-trans-4are: ethylcyclohexane, 53; tetramethylcyclopentane, 16; 1-cis-2-dimethylcyclohexane, 9; n-propylcyclopentane, 9; l-methyl-cis-2ethylcyclopentane, 6; 2,3,Strimeth>-lhexane, 5 ; and isopropylcyclopentane, 2.
A
S PART of the continuing nork of the American Petroleum
Institute Research Project 6 on the composition of its representative petroleum ( 7 ) ,analysis has been completed of the h>drocarbons in that fraction of the petroleum normally boiling between 126" and 132' C., which constitutes approximatel\ 0.68% by volume of the original crude. The status of this material prior to the present investigation is described in previouq papers ( 4 , 6 ) . The details of the analysis of the hydrocarbons in the adjacent lower-boiling fraction of this petroleum are given in another paper (3). DETAILS O F PROCESSIhG
All of the material from the previous nork, except a small amount of ethylcyclohexane, was blended and distilled to obtain in one lot all of the material from the original petroleum remaining in the range boiling normally from 126" to 132' C. The results of this distillation are given in Figure 1, which shows the location with respect t o boiling point and refractive index of the compounds found in this material. It is apparent that the first portion of the distillate consisted largely of n-octane, which nor1
Present address, Onyx Oil and Chemical Co , Jersey City, N. J. Institute of Industrial Research, Pittsburgh 13,
* Present address, Mellon Pa.
mally boils slightly below 126" C., and the portion just before the tail end consisted largely of ethylcyclohexane, which normally boils just below 132" C. The present analysis includes ethylcyclohexane but not n-octane, which is covered in the analysis of the next lower-boiling material (3). The material was processed by distillation (regular, azeotrope, and at reduced pressure) and by adsorption in a sequence designed to concentrate the individual hydrocarbon compounds so that they could be identified m-ith reasonable certainty. The amounts of the individual compounds xere computed from the results of spectrographic analyses made on appropriate intermediate and final fractions by the Research Laboratory of the Humbleboil and Refining Co. The processing of the material by distillation, following the distillation shown in Figure 1, is summarized as follows (see 8 for details of the distilling apparatus and procedures): Lot 1-B, from Figure 1, Part B, 1870 ml., was distilled a t 725 mm. of mercury. The results are s h o m in Figure 2, Part I. Lot 2-I-C, from Figure 2, Part I-C, 1460 mi., was distilled a t 56 mm. of mercury. The results are shown in Figure 2, Part 11. Lot 2-11-A, from Figure 2, Part II-.4, 505 ml., was distilled azeotropically with ethylene glycol monoethyl ether (Cellosolve) a t i25 mm. of mercury. The results are shonn in Figure 2, Part 111. Lot 2-11-B, from Figure 2, Part 11-B, 400 ml., was also distilled azeotropically with ethylene glycol monoethyl ether at 725 mm. of mercury. The results are shown in Figure 2, Part IV. Lot 2-11-C plus 2-IV-A, from Figure 2, Part 11-C plus Part IV-A, 580 ml., was also distilled azeotropically with ethylene glycol monoethyl ether a t 725 mm. of mercury. The results are shown in Figure 2, Part V. Lot 2-111-B, from Figure 2, Part 111-B, 285 ml., was distilled at 725 mm. of mercury. The results are shown in Figure 3, Part I. Lots 3-I-A and 3-I-C, from Figure 3, Parts I-A and I-C, plus cj-cloparaffin concentrates separated from Lot 1-A, from Figure 1, and Lot 2-111-A, from Figure 2, total charge of 250 ml., were distilled regularly a t 725 mm. of mercury. The results are shown in Figure 3, Part 11. Lots 3-I-B and 3-11-B, from Figure 3, Parts I-B and 11-B, 205 ml., were distilled axeotropically a t 725 mm. of mercury. The results are shown in Figure 3, Part 111. Lot 2-V-A, from Figure 2, was further fractionated by adsorption with silica gel in a tall column (1 by 790 cm.) to give the results shown in Figure 4 (see 6 for details regarding the apparatus and procedure for fractionation by adsorption). In the foregoing, the lots of material are identified with reference to the figure in which the results are plotted. Thus, Lot 2-I-B refers to Figure 2, Part I, Portion B.
1925
V O L U M E 28, NO. 12, D E C E M B E R 1 9 5 6 1321
1
1
,
I
o,BOILINS
144
i
POINT
--?
Figure 1.
Results of regular distillation of 126" to 132" C. fraction of petroleum
Table I.
Results of Spectrographic Analysis of Selected Lotsa Compounds
lsopropyl cyclopentane
n-Octane
l-irans-2-ris-3trans-&tetrameihylcyclopentane
1-Methyl-cis2-ethylcyclopentane
IR
31
IR
ir
IR
63
G4
15
13
21 37 42 3
4-8
n-Propylcyclopentane
Ethylcyclohexane
2,3,5-Trimethylhexane
c/o b y Volume in Lot
Lot b 3-II-.i 3-11-CC 3-111-B &.I=
I-cts-2Dimethylcyclohexane
9
RI 21 38 41
0
IR
hi
1 29 52 5 1
1 33 54
7
IR 13 0 45 13
ni
IR
12 1
2
45
1
17
1
49
RI
IR
11
11 16
14
IR
M
3 8
11
1
2
48
2
Spectrographic analyses made b y Research Laboratory, Humble Oil and Refining Co., Bayiown, T e x . Values in columns headed I R were obtained from infrared measurements. Values in columns headed RI were obtained from mass spectrometer measurements. b Lots identified in Figures 3 and 4. 3-11-.I refers t o Figure 3 P a r t I1 Portion A. Spectrometric examination indicated t h a t these samples coniained a i unidentified constituent, probably another tetrameihylcyclopentane.
RESULTS OBTAINED
The distillation shown in Figure 1 seived principal11 to sepalate the bulk of the n-octane at the front end and ethylcyclohexane near the tail end from the remaining six compounds. A small additional amount of ethylcyclohexane was separated a t the tail end of the azeotropic distillation, which is shown in Figure 2, Part I. The distillation a t reduced pressure (Figure 2, Part 11) effected a considerable separation of the remaining material. The azeotropic distillation shown in Figure 2, Part 111, concentrated l-trans-2-cis-3-trans-~-tetramethylcyclopentane in the middle portion of the distillate and the l-methyl-cis2-ethj-lcyclopentane in the final portion. The azeotropic distillations shown in Parts IV and V of Figure 2 gave a portion (Lot 2-V-A)consisting almost entirely of 1-cis-2-dimethylcycloheuane, n-propylcyclopentane, and 2,3,5-trimethylhexane. Figure 3 gives the results of the distillation operations required to obtain the best sample (Lot 3-111--4)of l-trans-2-cis-3-trans4-tetramethylcyclopentane,and a concentrate (Lot 3-111-B)of 1-methyl-cis-2-ethylcyclopentane. The adsorption experiment shoun in Figure 4 served to separate 1-cis-2-dimethylcyclohexane from n-propylcyclopentane.
The results of the spectrographic analyses are given in Table I. The spectrographic analyses were straightforward for six of the compounds, as API Standard samples of these were available. For l-trans-2-cis-3-trans-4-tetramethylcyclopentaneJ no standard sample was available and the isolated sample, estimated to have a purity of 90 mole yowas used for calibration for this compound. From the values of the simple physical properties of the Ca and COalkyl cyclopentanes given by the API Research Project 44, the identity of this compound appears certain (1). The spectrographic data were used in conjunction with the data on boiling points and refractive index as a function of volume to estimate the relative amounts of the individual components. Table I1 summarizes the information regarding the seven hydrocarbon compounds found in the 126" to 132" C. fraction of petroleum, giving the name and formula of the compound, the normal boiling point of the pure compound, the highest concentration of the given compound isolated, the lot in which the highest concentration was found, the estimated relative amount of the given compound in the 126" to 132" C. fraction of this petroleum, and the estimated amount by volume of the given compound in the original petroleum. It is seen that the 126" to 132" C. frac-
1926
ANALYTICAL CHEMISTRY 6 3 1 i l N G ?O N T
AT
7 2 5 m n HG
IN 'C
(AZEOTROPIC)
Figure 2.
Results of distillation of Lots 1-B, 2 - 1 4 , 2-11-A, and 2-IV-A
- HG
BOILING POINT AT 7 2 5 mm
-
-
N
N
*
0
Yn-OCTANE
IN " C
-
N
N
1
1
L
-A
ISOPROPYLCYCLOPENTANE
I
X
%
2 '
0
c
0
1
I
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BOILING
AT 56
POINT
I
I
I
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IN
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D *-I,
a
trcns- 2, c 8s-3, ' r O n i . 4 TETRAMETHYLCYCLOPENTANE
4
$\
H
I-METHYL- CIS-2-EThYLL~YZPENTANE-. x
BCIL'hG PWNT AT 7 2 5 mm
I
I
%
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OI
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s
4
1
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YCCTANE
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BOILING POINT A? 7 2 5 rnrn HG IN O C [AZEOTROPIC) 8
9
Cl
8
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ISOPROPYLCYCLOPENTANE
7
i
-
I I
T
I
-
0-
O
5)-
ib
-m
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REFRACTIVE I
I
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INDEX.tl,
e A? 25
e
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Figure 3. Results of distillation of Lot 2-111-B, involving concentration of l-trans-Z-cis-3-trans-4tetramethglcyclo pentane
V O L U M E 2 8 , NO. 1 2 , D E C E M B E R 1 9 5 6
1927
Summary of Seven Hydrocarbons Found in 126' to 132' C. Fraction of Petroleum
Table 11.
Compound Name Formula Isopropg lcyclopentane 1-trans-2-cis-3-lrans-4-tetramethyleyclopentane 1-Methyl-cis-2-ethylcyclopentane 1-cis-2-Dimethvlcvclohexane n-Propylc yclofentane 2,3,&Trimethylhexane Ethylcyclohexane
Boiling Point of Pure Compound a t 1 .4tm., O C. 126.42 127.4 128.03 129,73 130.95 131.34 131.78
Highest Concn. Isolated, LIole % 13
Highest Concn. Found in Lot 3-11-A
$0 52 45 49
3-111-A 3-111-B 4-.1 4-B 4-B 2-T-B
16
94
Total
tion of this petroleum is estimated to constitute 0.68% by volume of the original petroleum. The analyses reported by Bell ( 2 ) for an East Texas petroleum compare favorably vith the resulte of this investigation.
I I
Y
43i
-
-r--
0 0
in N
1
-
L-
$ 1
5
z a
W
W
L
1
z W
e
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2L
i -
Estd. Estd. Relative Am,ount Amount in of Given Original Compound Petroleum, by Vol. Vol. 47, 2 0 01
16 6 9 53
0.11 0.04 0.06 0.06 0.03 0.37
100
0.68
9
il
-
pentane, both estimated to be near 130" C.; and 1,l-cis-2-trans3-tetramethylcyclopentane, estimated to be near 131' C. The two trimethylhexanes are believed to be present only in trace amounts and the three tetramethylcyclopentanes, if actually normally boiling below 132' C., are believed to be present only in very small or trace amounts, as indicated in footnote of Table I. From the data given in Table 11, it is seen that the seven compounds which compose essentially all of the 126" to 132' C. fraction of this petroleum are of the branched paraffin, alkyl cyclopentane, and alkyl cyclohexanes classes. The relative amounts of these three classes of hydrocarbons in the 126' to 132" C. fraction are, respectively, 5 , 33, and 62. This makes the cycloparaffin content of this fraction 95%. ACKNOWLEDGMENT
I
D
Grateful acknowledgment is made to the Research Laboratory of the Humble Oil and Refining Co., Baytom, Tex., for the spectrographic analyses reported in this paper.
> I Iw
W
z
2
L
LT
i, a
c
2 w
LITERATURE CITED
LT
X
(1) American Petroleum Institute Research Project 44, "Selected
4
1 4 o l - o
2'0
30
(5)
Values of Properties of Hydrocarbons and Related Compounds," F. D. Rossini, Carnegie Institute of Technology, Pittsburgh, Pa. Bell, RI. F., ANAL.CHEM.22, 1005 (1950). Glasgow, 9.R., Jr., Gordon, R. J., Willingham, C. B., Mair, B. J., Rossini, F. D., unpublished manuscript. Leslie, R. T., J . Research Natl. Bur. Standards 22, 153 (1939). Rlair, B. J., Gaboriault, A. L., Rossini, F. D., Ind. Eng. Chem. 39,
(6)
Rose, F. W., Jr., White, J. D., J . Research Natl. Bur. Standards
40
VOLUME IN MILLILITERS
(2) (3)
Figure 4. Results of fractionation of Lot 2-V-A by adsorption, involving separation of 1 cis 2 dimethylcyclohexane and n-propylcyclopentane
- -
-
(4)
1072 (1947).
15, 151 (1935).
In addition to the seven hydrocarbon compounds found, the only other hydrocarbons of the paraffin, alkyl cyclopentane, and alkyl cyclohexane classes normally boiling in the range 126' to 2,2,4-trimethylhexane at 126.j40 1 3 2 ~C. are the follon.ing C.; 2,4,4-trimethy1hesane at 130.650 c.; 131-czs-2-cis-4tetramethylcyclopentane and 1,1-cis-2-trans-4-tetramethylcyclo-
(7) Rossini, F. D., hlair, B. J., Streiff, A. J., "Hydrocarbons in Petroleum," Reinhold, i i e w York, 1953. (S) JJ-illingham, C. B., Rossini, F. D., J . Research NatZ. Bur. Standards 3, 15 (1946). RECEIIED for review J u n e 8, 1953. Accepted Bugust 24, 1956. This report %as prepared as part of the work of t h e American Petroleum Institute Research Project 6 a t the Carnegie Institute of Technology. P a r t of t h e work Tlas completed a t the Natlonal Bureau of Standards prior t o J u l y 1, 1950. u hen the project nas transferred t o the Carnegie Institute of Technology.
