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Energy & Fuels 1990,4, 482-488
actions carried out in anhydrous cyclohexane. Alkanes, alkyl ethers, alcohols, and sulfides were essentially unreactive under the aqueous conditions a t 250 "C, but mercaptans reacted slowly to form sulfides with the evolution of hydrogen sulfide.20 (20) Katritzky, A. R.; Murugan, R.; Balasubramanian, M.; Siskin, M.; Brons, G. Part 19; Manuscript in preparation. (21) Unpublished results and Scouten, C. G.; Siskin, M.; Rose, K. D.; Aczel, T.; Colgrove, S. G.; Pabst, R. E., Jr. Prep.-Am. Chem. Soc., Diu. Pet. Chem. 1989, 34, 43.
Acknowledgment. The technical assistance of and helpful discussions with Drs. A. R. Lapucha and F. J. Luxem are gratefully acknowledged. The efforts of Dr. J. V. Greenhill and Ms. Annemarie Bishop in preparing the manuscript are also acknowledged. Supplementary Material Available: Text describing mass Tables IA and IB listing (IA)and spectral fragmentation patterns (IA and IB),Of compounds in this Paper (11 Pages). Ordering information is given on any current masthead page.
Aqueous Organic Chemistry. 2.' Cross-Linked Cyclohexyl Phenyl Compounds Michael Siskin* and Glen Brons Corporate Research Science Laboratories, Exxon Research and Engineering Company, Annandale, New Jersey 08801
Alan R. Katritzky* and Ramiah Murugan Department of Chemistry, University of Florida, Gainesville, Florida 32611-2046 Received April 5, 1990. Revised Manuscript Received June 7, 1990 Six cyclohexyl phenyl linked compounds of type PhXC6Hll were studied at 250 "C for s1l2days under aquathermal and thermal conditions. Cyclohexylbenzene, (cyclohexylmethyl)benzene, and cyclohexyl phenyl ketone were inert, while the amine-nitrogen, ether-oxygen, and sulfide-sulfur linkages all showed considerable reactivity. In the presence of an acidic clay (calcium montmorillonite), the ether reaction was catalyzed to the greatest extent followed by the amine and then the sulfide. Brine also caused a greater conversion with ether than with amine or sulfide. Basic conditions (calcium carbonate) decrease the reactivity of the nitrogen-, the oxygen-, and the sulfur-linked compounds under both thermal and aquathermal conditions, reinforcing the proposed acid-catalyzed ionic mechanism. The major reaction product in all cases was methylcyclopentene or cyclohexene, with the expulsion of aniline, phenol, or thiophenol, respectively. Pathways are proposed for the formation of these products from each of the cross-linked compounds, and the geochemical implications of brine and clay catalysis in kerogen maturation are discussed.
Introduction Cycloalkyl aryl ethers and the corresponding sulfides and aryl(cycloalky1)methanes have been identified as abundant bridges (cross-links) within the macromolecular network of an immature Kimmeridge shale.2 To generate high yields of oils, it is necessary to cleave these cross-links. It was reasoned that thermal treatment a t 425 "C of cycloalkyl species connected by these linkages should cause aromatization. The resulting diary1 species connected by ether, sulfide, and methylene linkages would be thermally stable. In the presence of 2000 psig hydrogen, the aromatization reaction was retarded and thermal cleavage of these linkages proceeded to form products of lower molecular weight. These considerations rationalize the fact that conversion of the Kimmeridge shale produced approximately 50% liquids under thermal vs approximately 90% under noncatalytic hydroconversion condition^.^ The chemistry described above cannot be extrapolated to catagenesis of kerogens to generate petroleum because of the high temperatures involved as well as the anhydrous (1)For previous paper see: Siskin, M.; Brons, G. Katritzky, A. R.; Balasubramanian, M. Energy Fuels, preceding paper in this issue. (2) Siskin, M.; Scouten, C. G. Unpublished results. (3) Olmstead, W. N.; Bond, J. E. Unpublished results.
reaction conditions. To obtain a better understanding of the reaction of these types of linkages under aqueous conditions, a study was initiated on six model compounds: N-cyclohexylaniline, cyclohexyl phenyl ether, cyclohexyl phenyl sulfide, cyclohexyl phenyl ketone, (cyclohexylmethyl)benzene, and cyclohexylbenzene. Each compound was subjected to heating in water, brine, and nonane systems. Also, each system was run in the presence of (a) calcium montmorillonite and of (b) calcium carbonate. Reactions in nonane allow for the differentiation between thermal chemistry and aqueous chemistry. The a q u e o u s reaction sets with brine and minerals were performed to elucidate aqueous chemistry in environments that simulated maturation.
Experimental Section N-Cyclohexylaniline, cyclohexyl phenyl ketone, (cyclohexylmethyl)benzene, and cyclohexylbenzene (all >98% purity) were obtained from Aldrich. The purity of all starting materials was checked by GC prior to use. Water and brine (10% NaCl) were deoxygenated just before use. The clay used was calcium montmorillonite (Gonzales County, TX, STx-1: Clay Minerals Society, Source Clay Minerals Repository, University of Missouri). Calcium carbonate powder was obtained from Mallinckrodt. All the GC analyses were done on a Hewlett-Packard 5890 instrument (flame ionization detector, FID)with a capillary column (HP-l),
0887-0624/90/2504-0482$02.50/0 0 1990 American Chemical Society
Aqueous Organic Chemistry. 2
Energy & Fuels, Vol. 4, No. 5, 1990 483
Table I. Structure and Identification of Starting Materials and Products no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
tR, min 0.20 0.22 0.27 0.44 0.74 0.98 0.99 1.29 1.41 1.63 1.80 1.86 2.53 5.71 6.24 6.55 6.82 6.84 7.03 7.26 7.58 7.76 7.83 8.10 8.15 8.30 8.30 8.58 8.64 8.71 8.84 8.93 8.95 9.13 9.14 9.22 9.72 10.02 10.65 10.93 12.74 12.95 13.41 13.86 13.92 14.03 14.99 15.34 15.89 16.05
structure
mol wt benzene 78 l-Me-c-C5H, 82 cyclohexene 82 toluene 92 2-Me-c-C5H,0 98 cyclohexanone 98 c-C~H~~-NH~ 99 cyclohexanol 100 C-C~H~I-SH 116 thiophenol 110 aniline 93 phenol 94 2-CH20H-cyclohexanol 130 l-c-C6Hll-cyclohexene 164 biphenyl 154 1-C&,-C-C6Hg 158 3-C&,-C-C&g 158 C-CeH11-O-CgjH5 176 hexahydrodibenzofuran 174 c-CsHll-C6H5 160 c-C~H~CHZ-S-C~H, 192 1-phenylcyclopentene 144 2-(c-C5HgCHz)thiophenol 192 4-(c-C5HgCH,)thiophenol 192 2-(cyclopentylmethyl)phenol 176 4-(cyclopentylmethyl)phenol 176 1-(4-SH-C6H4)-1-Me-c-C5H* 192 C-C~H~I-NH-C~H, 175 2-(cyclopentylmethy1)aniline 175 2-c-C6Hll-phenol 176 192 C-CSH~~SC~H~ 2-cyclohexylthiophenol 192 175 2-c-C6H11-aniline 4-cyclohexylthiophenol 192 4-c-C6Hll-phenol 176 4-c-C6Hll-aniline 175 tetrahydrodibenzothiophene 188 c-C6H11-S-C6H4-4-Me 206 224 C-C6H1,-S-S-C& C&,-S-S-C& 218 2,6-dicyclohexylphenol 258 C6H~-S-S-S-C6H5 250 hexahydrocarbazole 173 2-(c-C6Hll)hexahydrocarbazole 255 2,4-dicyclohexylphenol 258 4- (cyclohexylthio)biphenyl 268 2-(c-C6H11)-6-(c-C5H9CHZ)aniline 257 2,6-dicyclohexylthiophenol 274 4-(c-C6H11)-2-(c-C5HgCHz)aniline 257 2,4-dicyclohexylthiophenol 274
equiv wt 78 82 82 92 98 98 99 100 116 110 93 94 130 164 154 158 158 176 174 160 192 144 192 192 176 176 192 175 175 176 192 192 175 192 176 175 188 206 224 109 129 125 173 127.5 129 134 123.5 137 123.5 137
identification basis" Table IA Table IB Table IA Table IA Table IB Table IA Table IB Table IA Table IB Table IA Table IA Table IA Table I1 Table I1 Table IB Table IB Table I1 Table IA Table I1 Table IB Table I1 Table I1 Table I1 Table I1 Table I1 Table I1 Table I1 Table IA Table I1 Table I1 Table IA Table I1 Table I1 Table I1 Table I1 Table I1 Table IB Table I1 Table I1 Table IA Table I1 Table I1 Table I1 Table I1 Table I1 Table I1 Table 11 Table I1 Table 11 Table I1
response factor 0.97 0.97 0.97 0.96 0.79 0.79 0.72 0.79 0.72 0.72 0.72 0.79 0.60 0.94 0.94 0.94 0.94 0.74 0.74 0.94 0.68 0.94 0.70 0.70 0.76 0.76 0.70 0.69 0.69 0.76 0.68 0.70 0.69 0.70 0.76 0.69 0.68 0.68 0.42 0.42 0.73 0.17 0.69 0.66 0.73 0.65 0.66 0.67 0.66 0.67
'Tables IA and IB are supplementary material.
and a temperature program of 10 "C/min from 50 to 250 "C was used. Cyclohexyl Phenyl Ether (18). Phenol (9.4 g, 0.1 mol), potassium hydroxide (10 g), and dimethyl sulfoxide (100 mL) were stirred a t room temperature for 5 min. Chlorocyclohexane (11.8 g, 0.1 mol) was then added and heated at 100 "C for 6 h. The reaction mixture was poured into icewater (250 g), extracted with ether, and washed with sodium hydroxide (10% solution) and then with water. The ether was evaporated, and the residue was vacuum distilled to give cyclohexyl phenyl ether (2.6 g, 15% yield) with bp 100-105 "C/5 mm (lit.4 bp 101-103 "C/3 mm). Cyclohexyl Phenyl Sulfide (31). Thiophenol(ll.0 g, 0.1 mol) and cyclohexene (8.2 g, 0.1 mol) were irradiated with a sun lamp for 8 h. The product mixture was dissolved in ether and washed with aqueous sodium hydroxide (10%) and then with water. The ether was evaporated, and the residue was vacuum distilled to give cyclohexyl phenyl sulfide (17.3 g, 90%) with bp 115 "C/3 mm (lit.5 bp 108 "C/O.l mm). (4) Abduraeuleva, A. R.; Akhemdov, K. N.
Uzb.Khim. Zh.1964,8,31;
Chem. Abstr. 1965,62, 10356b. (5) Cunneen, J. I. J . Chem. SOC.1947, 36.
General Procedure for Aquathermal Reactions. T h e aquathermolyses were conducted at 250 "C for 5 1 / 2 days as previously described! The gas chromatographic behavior of all the compounds encountered in this work (starting materials and products) is summarized in Table I. Table IA records the source and mass spectral fragmentation patterns of the authentic compounds used, either as starting materials or for the identification of products. Tables IB and I1 record the mass spectral fragmentation patterns of products for which authentic samples were not available, and which were identified by comparison with literature MS data (Table IB) or by deduction from their mass spectral fragmentation pattern (Table 11). The results from the aquathermolyses are collected in Table I11 and onward. Tables IA and IB are available as supplementary material (see paragraph a t end of paper regarding supplementary material). Conversion Yields and Material Balance. All conversions and yields are given in terms of moles and a percentage of starting material. Internal standards were used to quantify conversion (6) Part 1 of the series Aqueous High-Temperature Chemistry of Carbo- and Heterocycles. Katritzky, A. R.; Lapucha, A. R.; Murugan, R.; Luxem, F. J.; Siskin, M.; Brons, G. Energy Fuels, in this issue.
484 Energy & Fuels, Vol. 4, No. 5, 1990 Table 11. compound 2-CHIOH-cvclohexanol l-c-CiHll-c;clohexene 3-C&j-C-C6Hg hexahydrodibenzofuran C-C~H~CHZ-S-C~H, 1-phenylcyclopentene 2-(c-C5HgCHz)thiophenol 4-(c-C5HgCHz)thiophenol 2-(cyclopentylmethyl)phenol 4-(cyclopentylmethy1)phenol
no. 13 14 17
19 21 22 23 24 25 26 27 29 32 34 38 39 41 42 43 44 45 46 47 48 49 50
Siskin et al.
Identification of Products from Mass Spectral Fratinnentation Patterns fragmentation pattern m / r ( % relative intensity, structure of fragment ion) MW 130 130 (25, M); 94 (100, M - 2HZO); 82 (20, M - CH4Oz); 67 (30, C5H7); 55 (25, c4H.1)
164 164 (50, M); 122 (20, M - C3H6); 81 (100, M - C6Hll); 67 (95, 81 - CHJ; 55 (100, C4H7) 158 158 (50, M); 130 (40, M - C2H4); 115 (100, M - C3H7); 91 (40, C7H7); 77 (35, CeH5) 174 174 (100, M); 145 (30, M - CHO); 131 (75, 145 - CHZ); 91 (35, C7H7); 77 (85, C6H5) 192 192 (35, M); 148 (10, M - CS); 135 (15, M - C4H9); 110 (100, M - C6H10); 83 (20, C6H11) 144 144 (90, M); 104 (60, M - C3H4); 77 (100, C6H5); 51 (75, C4H3); 39 (50, C3H3) 192 192 (45, M); 148 (5, M - CS); 135 (25, M - C4H9); 110 (100, M - CsHio); 83 (15, C6H11) 192 192 (55, M); 135 (40, M - C4Hg); 110 (100, M - C6Hlo); 83 (25, C6H11); 77 (15, C6H5) 83) ;(50, C6Hll) 176 176 (30, M); 161 (100, M - CH3); 147 (35, 161 - CH&; 107 (45, C H Z C ~ H ~ O H 176 176 (40, M); 161 (100, M - CH3); 147 (25, 161 - CHz); 107 (40, C7HyO); 83 (60, C6H11) 192 192 (90, M); 135 (25, M - C4Hg); 110 (100, C6H5SH); 77 (25, C6H5); 65 (35, C5H5) 1-(4-SH-C6H4)-1-Me-c-C5H8 2-(cyclopentylmethy1)aniline 175 175 (60, M); 160 (100, M - CHJ; 146 (50, M - CzH5); 106 (95, M - C5Hg); 91 (55, C7H7) 192 192 (65, M); 110 (100, M - C6H10); 83 (30, M - C6HsS); 77 (25, C7H5); 65 (45, C5H5) 2-cyclohexylthiophenol 192 192 (50, M); 110 (100, M - C6H10); 83 (40, M - C6H5S); 65 (35, C5H5); 55 (45, C4H7) 4-cyclohexylthiophenol 206 206 (40, M); 97 (40, M - CsHsS); 77 (30, CtjH5); 69 (65, 97 - CzH4); 65 (40, C5H5) c-C6HI1-S-C6H4-4-Me 224 224 (90, M); 142 (100, M - C6H10); 109 (60, CeHsS); 83 (35, CBH11); 77 (60, C6H5) C-C6H,,-S-S-C& 258 258 (60, M); 176 (100, M - C6H10); 133 (40, 176 - C3H7); 107 (65, C7H70); 91 (40, C7H7) 2,6-d1cyclohexylphenol 250 250 (100, M); 141 (80, M - CsHsS); 109 (80, 141 - S); 77 (65, C6H5); 65 (70, C5H5) C~H~-S-S-S-C~HS 173 173 (35, M); 130 (55, M - C3H7); 77 (100, C6H5); 65 (15, C5H5); 51 (60, C4H3) hexahydrocarbazole 255 255 (45, M); 212 (40, M - C3H7); 172 (100, M - C6H11); 130 (60, 172 - C3H6); 115 (35, 130 - NH) 2-(c-C6Hll)hexahydrocarbazole 258 258 (60, M); 176 (100, M - C6H10); 145 (15, 176 - OCH,); 107 (25, C&O); 91 (30, C7H7) 2,4-dicyclohexylphenol 268 268 (100, M); 197 (65, M - C5H11); 165 (35, 197 - SI;115 (80, C ~ H I ~ S77) ; (65, C6H5) 4-(cyclohexylthio)biphenyl 257 257 (100, M); 186 (70, M - C5H11); 174 (30, M - C&11); 130 (70, 186 - C4H8); 106 (75, C7H8N) ~-(c-CBH~I)-~-(C-C~H~CH~)aniline 2,6-dicyclohexylthiophenol 274 274 (100, M); 192 (95, M - CBH10); 149 (55, 192 - C3H7); 135 (60, 149 - CHJ; 115 (35, C6H11S) ~ - ( c - C ~ H , , ) - ~ - ( C - C , H ~ C H257 ~ ) - 257 (100, M); 186 (80, M - C5Hll); 174 (35, M - CsH11); 130 (65, 186 - C4H8); 106 (80, C7H8N) aniline 2,4-dicyclohexylthiophenol 274 274 (100, M); 192 (45, M - C6H10); 159 (20, 192 - SH); 135 (35, 192 - C4Hg); 115 (30, C6H11S)
of the starting material, and the GC peak areas were corrected by response factors and then renormalized t o omit materials present in
