J. Org. C h e m .
2534
1984,49, 2534-2540
Syntheses and Reactions of the First Dithia[3.1.3.l]metacyclophanes, [2.1.2.11Metacyclophanes, and [2.1.2.1]Metacyclophanedienes' Reginald H. Mitchell* and Yee-Hing Lai Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada V8 W 2Y2 Received August 11, 1983
Two new cyclophane series, the dithia[3.1.3.l]metacyclophanes 5 and the [2.1.2.l]metacyclophanedienes6, are synthesized and their chemistry is described. On the basis of this chemistry, such cyclophanes appear not to adopt the syn or anti conformations found in the [2.2]metacyclophanes,but a geometry in which the X,Y groups are distant in space.
Introduction Cyclophanes have attracted considerable attention over the last two decades because of their interesting stereochemistry and potential interring electronic interactions.2 Most attention however has been given to the lower members of the series, with very little information available at the start of this work on higher ~yclophanes.~Specifically we were interested in [3.1.3.1]- and [2.1.2.1]metacyclophanes, which have exceptionally interesting stereochemistry in that either the stepped conformation of the syn- and anti-[2.2]metacyclophanes,e.g., 1, could be adopted, or a more open crown type structure, e.g., 2.
We therefore chose 5 to access the [2.1.2.l]cyclophanes 6, and thought that interesting X,Y groups in 5 and 6 would be combinations of C=O and CH2 for three reasons. Firstly, this made the precursors 7 synthetically accessible.
JpZ
Y +X+Y
1
8
Results and Discussion Dithia[3.3] cyclophanes have been extremely fruitful precursors to both [2.2]cyclophanes and cyclophanedienes.6
Secondly, variation of the X,Y bridge as sp3 or sp2 units might change the geometry adopted by 5 or 6, and thirdly, such groups provided several options to examine the chemistry of bridge formation in the products 6. Thus the initial synthetic objective chosen was 5 (X = CO, Y = CH2) requiring the dibromide 7A (X = CO, Y = CH2Br)and the dithiol7B (X = CH2, Y = CH2SH). Reaction of commercial 2,6-dichlorotoluene 8A (Y = Z = C1) with 1.1equiv of CuCN yielded 2-chloro-6-cyanotoluene 8B (Y = C1, Z = CN) more easily than previous routes.8 Reduction of this nitrile with Dibal in benzene then yielded aldehyde 8C (Y = C1, Z = CHO), which on further reduction with NaBH4 in THF gave alcohol 8D (Y = C1, Z = CH20H) in overall 39% yield from 8A (Y = Z = Cl). This alcohol was also obtained from the monoGrignard reagent 8E (Y = C1, Z = MgC1) with paraformaldehyde. Treatment of alcohol 8D (Y = C1, Z = CH20H) with PBr3 gave bromide 8F (Y = C1, Z = CH2Br), which with methoxide ion gave ether 8G (Y = C1, Z = CH20CHa. This could also be obtained from alcohol 8D with NaH followed by methyl iodide. Formation of the Grignard reagent 8H (Y = MgCI, Z = CH20CH3)was exceptionally difficult. Iodine-activated magnesium! or RiekeZ0magnesium prepared from potassium and MgBr2, or magnesium generated from MgC12and sodium naphthalenidel' all failed to react. Use of 2 equiv of magnesium with 1 equiv of 1,2-dibromoethane as an entrainment reagenP did however give the Grignard 8H (Y = MgC1, Z = CH20CHJ, which on reaction with ethyl formate gave 60% of the alcohol 7C (X = CHOH, Y = CH20CH3),mp 113-114 "C. This alcohol could also be obtained by reaction of Grignard 8H (Y = MgC1, Z = CH20CH3)with aldehyde 81 (Y = CHO, Z = CH20CH3),itself obtained by conversion of 8G (Y = C1, Z = CH20CH3)into nitrile 85 (Y = CN, Z = CH20CH3)as previously with CuCN, and
(1) Taken from the doctoral thesis of Yee-Hing Lai, University of Victoria, Sept, 1980. (2) (a) Keehn, P.; Rosenfeld, S. 'Cyclophanes"; Academic Press: New York, 1983. (b) Vogtle, F. 'Cyclophanes"; Springer-Verlag: Heidelberg, 1983. (3) For a comprehensive review of cyclophane conformations, see: Mitchell, R. H. In 'Cyclophanes"; Keehn, P., Rosenfeld, S., Eds.; Academic Press: New York, 1983; Chapter 4. (4) Mitchell, R. H.; Lai, Y. H. Tetrahedron Lett. 1980, 21, 2633. (5) .(a) For a review, see: Mitchell, R. H. Zsr. J. Chem. 1980,20,594. (b) Mitchell, R. H.; Williams, R. V.; Mahadevan, R.; Lai, Y-H.; Dingle, T. W. J. Am. Chem. SOC.1982,104, 2571.
(6) For a review, see: Mitchell, R. H. Heterocycles 1978, 11, 563. (7) All compounds prepared were satisfactorily characterized by 'H spectroscopy,IR (where appropriate),and elemental analysis NMR, (new) and were obtained pure by TLC unless otherwise stated. (8) Lindsay, W. S.;Stokes, P.; Humber, L. G.; Boekelheide, V. J. Am. Chem. SOC.1961,83,943. (9) Gilman, H.; Kirby, R. H. Red. Trav. Chim. Pays-Bas 1935,54,577. (10) Rieke, R. D.; Bales, S. E. J. Am. Chem. SOC.1974, 96, 1775. (11) Arnold, R. T.; Kulenovic, S. T. Synth. Commun. 1977, 7, 223. (12) Pearson, D. E.; Cowan, D.; Beckler, J. D. J. Org. Chem. 1959,24, 504.
W 1
2
5
6
In the event that a stepped structure was adopted, closure of a bond between X-X of 1 would lead to the edge fused metacyclophanes 3, potential precursors to the interesting [14]annuleno[l4]annulene4. In either case determination of the conformational preferences of such cyclophanes, particularly as the hybridization of the bridges is changed, would yield knowledge useful in future targeting of synthetic schemes designed to yield more highly fused ring systems.
0022-326318411949-2534$01.50/0 0 1984 American Chemical Society
J. Org. Chem., Vol. 49, No. 14, 1984 2535
Syntheses and Reactions of Metacyclophanes reduction of this with Dibal in benzene. Jones oxidation13of the alcohol 7C (X = CHOH, Y = CH20CH3) gave ketone diether 7D (X = CO, Y = CH20CH3), mp 65-66 "C, which with refluxing 48% HBr-concentrated H2S04 (2:l)gave the desired ketone dibromide 7A (X = CO, Y = CH2Br), mp 162-163 "C. Direct reduction of alcohol 7E (X = CHOH, Y = CH20CH3)with NaBH4 in CF3COOH14at 0 "C gave an excellent yield of the diarylmethane 7C (X= CH2, Y = CH20CH3),mp 53.5-55 "C, which on similar treatment with HBr-H2S04 gave dibromide 7F (X = CH2, Y = CH2Br),mp 115-116 "C. This was converted to the dithiol 7B (X = CH2,Y = CH2SH),mp 66.5-67.5 "C in 97% yield by the thiourea method.15 High dilution coupling16 of dithiol7B (X = CH,, Y = CH,SH) and dibromide 7A (X = CO, Y = CH2Br) gave after chromatography 7040% yields of the desired dithiacyclophane 5A (X = CO, Y = CHJ, mp 297-299 "C dec. Its molecular weight of 522 was indicated by a very intense MH+ peak in its chemicalionization (CI) mass spectrum and thus confirmed its structure as a dimer. Is 'H NMR spectrum, which showed the Ar2CH2protons as a singlet at 6 3.95 and the bridging -CH2S-protons also as a singlet at 6 3.74,together with two singlet methyl proton signals at 6 1.97 (>C=O unit) and 6 1.85 (>CH2 unit), indicated that 5A was a single conformationally mobile stereoisomer. Variable temperature studies later confirmed this and are discussed in detail in the subsequent paper of this issue. Further, no stereoisomerswere observed on thin-layer chromatography of 5A under conditions where they are readily observed in other systems.16J7 Conversion of 5A (X = CO, Y = CHJ into the cyclophanediene 6A (X = CO, Y = CHJ was thus investigated next. Wittig rearrangement16 of 5A (X = CO, Y = CH2)using lithium diisopropylamide (LDA) in THF followed by addition of methyl iodide gave a nonseparable mixture of products, however conversion of 5A to its bis(methy1 sulfonium) salt, 9, using the Borsch
2
Me-++
9
10
reagent'* (CH30)2C+HBF4-,followed by a Stevens rearrangement of 9 (t-BuOKITHF) gave a 50% yield of 10A (X = CO, Y = CH2, Z = SCHJ as a mixture of stereoisomers. The characteristic16 -SCH3 protons appeared at 6 1.90and a correct MH' peak at m / e 551 was observed in its CI mass spectrum. The final elimination to give 6A (X = CO, Y = CH2)could be achieved by two methods: remethylation of 10A (X = CO, Y = CH,, Z = SCH3)with (CH30I2C+HBF4-gave 89% of 10B (X = CO, Y = CH2, Z = S+(CH3)2BF4-)which on further treatment with tBuOK/THF gave the diene 6A (X = CO, Y = CH2) in 3045% yield. Alternatively oxidation of 10A (X = CO, Y = CH2, Z = SCH,) with bromine in aqueous potassium (13) Bowers, A.; Halsall, T. G.; Jones, E. R. H.; Lemin, A. J. J. Chem. SOC.1953, 2548. (14) Gribble, G. W.; Leese, R. M. Synthesis 1977, 172. (15) Speziale, A. J. "Organic Syntheses"; Wiley: New York, 1963; Collect. Vol. 4, p 401. (16) Mitchell, R. H.; Boekelheide, V. J. Am. Chem. SOC.1974;96,1547. Mitchell, R. H.; Otsubo, T.;Boekelheide, V. Tetrahedron Lett. 1975,219. (17) (a) Mitchell, R. H.; Williams, R. V.; Dingle, T. W. J. Am. Chem. SOC.1982,104,2560. (b) Mitchell, R. H.; Yan, J. S. H.; Dingle, T. W. Zbid. 1982,104, 2551. (18) Borch, R. F. J. Am. Chem. SOC.1968, 90,5303; J. Org. Chem. 1969, 34, 627. See also: Meerwein, H.; Bodenbenner, K.; Bomer, P.; Kunert, F.; Wunderlich, K. Liebigs Ann. Chem. 1960,632, 38.
bi~arbonate'~ gave a quantitative yield of the disulfoxide 1OC (X = CO, Y = CHz, Z = SOCH,), which on refluxing for 12 h in N-methyl-2-pyrrolidincrne gave 50-75% yields of 6A (X = CO,Y = CH21. In cyclophane chemistry6 thermal elimination of PhSOH has been more commonly used20 than MeSOH elimination, though the latter has been occasiondy used.21 In the above example it appears preferable to the base-catalyzed Me2S elimination. As obtained the diene 5A (X = CO, Y = CH2)was found by TLC and by NMR to be a mixture of stereoisomers in a 7525 ratio. Only small quantities of each stereoisomer could be obtained pure by chromatography. The major isomer, mp 291-293 "C, showed two distinct sets of two singlets each for the methyl protons: one set at 6 2.37 and 2.28,the other at 6 1.18and 1.09. One signal within each set was assigned to the methyls of the "benzophenone unit", the other to the "diarylmethane unit". Since in the case of the parent thiacyclophanes 11 and 12,the internal
11
12
methyl protons of the anti isomers 11 appear at 6 1.30 and those of syn-12 appear a t 6 2.54,we assumed that in this isomer of 6A (X = CO, Y = CHJ, we likewise had one set of anti-methyls and one set of syn-methyls and assigned this isomer the syn,anti structure 13. The minor isomer,
mp 286-288 "C, gave a similar mass spectrum to 13 with a strong MH+ peak in its CI mass spectrum. In its 'H NMR spectrum, however, all the methyl protons occurred as a singlet at 6 1.24 (the region of "anti-methyls") and thus the anti structure 14 was tentatively assigned. We assumed in this case there was an accidental chemical shift degeneracy between the methyls of the two halves of the molecule. To further support these initial assignments, for the major isomer 13, two clear sets of aryl hydrogens were observed, one set of 6 H in the syn aryl ring region at 6 6.684.13 and one set in the anti aryl region3at 6 7.47-6.98. The minor isomer 14 however only showed one set of aryl hydrogens at 6 7.64-7.06,in the anti aryl region. Both isomers showed AB multiplets for the olefinic protons, the major isomer showing JAB = 11.5 Hz, that of the minor isomer not being clear (only the inner lines were clear); the major isomer showed the -CHz- group as an AB at 6A 4.09 and 6B at 3.51 (JAB= 15 Hz) and the minor isomer as a singlet at 6 4.27. Moreover the more symmetrical isomer 14 would be expected by analogy to have a higher melting point than 13. Thus collectively we had no reason to doubt our original stereochemical assignments. However, after studying the chemistry of 13 we were forced to review these assignments (see below). Molecular models of 13 and 14 indicated that there should be no steric reason why in these conformations, formation of the central bridge should be inhibited, and indeed attack on the carbonyl by an external basic nu(19) Drabowicz, J.; Midura, W.; Mikokajnyk, M. Synthesis 1979,39. (20) Otsubo,T.;Boekelheide, V. Tetrahedron Lett. 1975,3881; J. Org. Chem. 1977,42, 1085. (21) Otaubo, T., Gray, R.; Boekelheide, V. J. Am. Chem. SOC.1978, 100, 2449. Kamp, D.; Boekelheide, V. J. Org. Chem. 1978, 43, 3475. Potter, S. E.; Sutherland, I. 0. J. Chem. Soe., Chem. Commun. 1973,520.
Mitchell and Lai
2536 J. Org. Chem., Vol. 49,No. 14, 1984 cleophile (rather than attack by the proximal methylene bridge, for example, after anion formation) looked unlikely! Irradiation of 6 A (X = CO, Y = CH2) (a mixture of 13 and 14) in CCl., with a medium-pressure mercury lamp/Pyrex apparatus merely returned unchanged starting material, as did reflux of the mixture with KH in THF, in complete contrast to the reaction of benzophenone with diphenylmethane, in which formation of 1,1,2,2-tetraphenylethanol under photolytic (radical) or basic (anionic) conditions is well documented.22 LDA in refluxing THF gave a brown color, but only unchanged 6 A was recovered after workup. n-Butyllithium generated a transient red color and gave the alcohol 6 E (X = C(OH)(n-Bu), Y = CH,) as the major product. Even the much less nucleophilic tert-butyllithium at -78 “C gave the alcohol 6F (X = C(OH)(t-Bu),Y = CH2) as a main product. None of the minor products could be identified as 3 (X-X= >C(OH)CH300 OC dec, and then was heated under reflux with KOH (10.66 g, 0.19 mol) in H 2 0 (100 mL) under N2 for 6 h. The mixture was cooled in an ice bath and concentrated H2S04/H20(l:l,20 mL) was added followed by dichloromethane. The organic extract was washed, dried, and evaporated. The residual oil was preadsorbed onto silica gel with pentane-dichloromethane (1:l)as eluant to yield 1.14 g (57%) of mercaptan 7G, which after recrystallization from benzene-pentane gave colorless crystals: mp 77-78 "C; 'H NMR (60 MHz) 6 7.53-7.12 (m, 6 H, Ar H), 3.82 (d, J = 7 Hz, 4 H, CH2SH),2.45 (a, 6 H, Ar CH,), 1.72 (t, J = 7 Hz, 2 H, SH); IR (KBr) 1660 (C=O), 1458,1435,1308,1280,1255,950,821,808, 762,730, 720, 685 cm-l; MS (EI) M'., m/e 302 (23), 287 (24), 270 (51), 269 (60), 255 (23), 253 (87), 235 (63), 234 (42), 233 (35), 222 (33, 221 (loo), 220 (24), 219 (24), 165 (56). Anal. Calcd for CI7Hl8OS2: C, 67.51; H, 6.00. Found: C, 67.46; H, 5.97. 9,16,25,32-Tetramethyl-lO,26-dioxo-2,18-dithia[3.1.3.1]metacyclophane 5B (X = Y = CO). A solution of dibromide 7A (X = CO, Y = CH2Br) (1.386 g, 3.5 mmol) and dimercaptan 7G (X = CO, Y = CH2SH) (1.059 g, 3.5 mmol) in N2 purged benzene (175 mL) was added dropwise over 12 h to a well stirred solution of KOH (590 mg, 10.5 mmol) in N2purged 90% ethanol (600 mL) at 20 "C under N2. After the solution had stirred 6 h,
2540 J. Org. Chem., Vol. 49, No. 14, 1984 the bulk of the solvent was removed under reduced pressure and dichloromethane and H20were added to the residue. The organic layer was washed and dried, silica gel (20 g) was added, and then the solvent was evaporated. The residue was slurried in dichloromethane onto a silica gel column and the product 5B was eluted with dichloromethane as highly insoluble white crystals: 1.265 g (67%) mp 326-331 "C dec; 'H NMR (90 M H z ) 6 7.35-7.15 (m, 12 H, Ar H), 3.67 (s,8 H, CH2S),1.88 (8, 12 H, Ar CH,); IR (KBr) 1655 (C=O), 1452,1305,1280,1260,1090,1025,950,799, 760,735,728cm-';MS (CI) MH', m / e 537 (7), 447 (lo), 249 (loo), 247 (88). Anal. Calcd for C34H3202S2: C, 76.08; H, 6.00. Found C, 76.23; H, 6.12. Stevens Rearrangement of 5B (X= Y = CO). A suspension of the thiacyclophane5B (161 mg, 0.3 mmol) in dichloromethane (5 mL) was added to (CH30)zCHBFJs(145 mg,0.9 mmol) stirred in dichloromethane (10 mL) under Nz at -30 "C. The mixture was stirred for 3 h without additional cooling and then ethyl acetate (3 mL) was added and stirring continued for 5 h. The bis(sulfonium) salt was then collected, washed with ethyl acetate, and dried to give 216 mg (97%), mp >300 "C dec. The salt (400 mg, 0.54 mmol) was suspended in dry THF (20 mL) under Nz and powdered potassium tert-butoxide (135 mg, 1.2 mmol) was added at about 20 "C. After 1.5 h, dilute aqueous HC1 was added, and then dichloromethane. The organic layer was washed, dried, and evaporated, and the yellow residue was chromatographed over silica gel with dichloromethane as eluant to yield 109 mg (36%) of 10D (X = Y = CO, Z = SCHd as bright yellow crystals and a mixture of stereoisomers: 'H NMR (90MHz) 6 8.1-6.2 (m, Ar H) 4.9-3.1 (m, CH(SCH,)), 2.9-1.7 (m), 1.95 ( 8 , SCH3), 1.5-1.0 (singlets, Ar CH,); MS (CI) MH', m / e 565 (100). M,calcd for CWHM0&, 564.2156; found (MS), 564.2147.
8,15,23,3O-Tetramethyl-9,24-dioxo[2.1.2.l]metacyclophane-l,l6-dienes 6B (X = Y = CO). A solution of Brz (0.55 "01) in dichloromethane (- 1mL) was added by syringe to a mixture of the Stevens rearrangement isomers 10D (X = Y = CO, Z = SCH,) (141 mg,0.25 mmol), dichloromethane (10 mL), and 10% aqueous NaHC0, solution (10 mL) vigorously stirred at 20 "C. After 30 min, dichloromethane was added and the organic layer was washed, dried, and evaporated. The residue was filtered through a short column of silica gel with dichloromethane and then methanol as eluant to yield 144 mg (97%) of mixed isomers of sulfoxides 1OE (X = Y = CO, Z = SOCH3)as white crystals: 'H NMR (60 MHz) 6 7.7-6.2 (m, Ar H), 4.5-3.2 (m, CH(SOCH3)) 2.8-1.7 (m), 2.40 (8, SOCH,), 1.5-1.2 (singlets, Ar CHJ. This sulfoxide (543 mg, 0.908 mmol) was heated at 150-160 "C in N-methyl-2-pyrrolidinone(20 mL) for 14 h. After cooling the mixture was poured into dilute aqueous HC1 and dichloromethane was added. The organic layer was washed well, dried, and evaporated. The residue was preadsorbed onto silica gel (2 g) and chromatographed over silica gel with benzene as eluant which gave firstly 221 mg (52%) of mixed isomers of 6B (2.5:l ratio): 'H NMR (90 MHz) 6 7.8-7.1 (m, Ar H), 6.82 ( 8 , CH=), 6.8-6.4 (m, Ar H), 2.41, 1.30, 1.14 (8, Ar CHJ. Eluted next was 32 mg (8%) of the pure major isomer of 6B (originallyassigned structure 15): mp 318-320 "C; 'H NMR (90 MHz) 6 7.5-7.2 (m, 6 H, anti Ar H), 6.82 (s,4 H, CH=CH), 6.7-6.4 (m, 6 H, syn Ar H), 2.39 (s,6 H, syn Ar CH3), 1.11 (s,6 H, anti Ar CHd; IR (KBr) 1670 (C=O), 1445,1274,1255,944,820,764,728,709 cm-'; MS (CI) MH+, m / e 469 (100). Anal. Calcd for CMHze02:C, 87.15; H, 6.02. Found: C, 87.47; H, 6.11. 9,24-Dihydroxy-8,15,23,30-tetramethy1[2.1.2.l]metacyclophane-l,l6-dienes 6D (X = Y = CHOH). A solution of the mixed isomers of diene 6B (X = Y = CO) (21 mg, 0.045"01) in wet THF (15 mL) was added to a suspension of N&H4 (5 mg, 0.13 mmol) in wet THF (100 mL) and the mixture was heated
Mitchell and Lai under reflux for 12 h. After the mixture had cooled, dilute aqueous HC1 was added and the product was extracted with ether. The organic layer was washed, dried, and evaporated and the residue was filtered through a short column of silica gel with dichloromethane as eluant to yield 18 mg (84%) of white crystals of mixed isomers of diol 6 D IR (KBr) 3390 (b, OH), 1450,1000,945,820, 796,768,728 cm-'; MS (CI) MH', m / e 473 (45), 454 (100). This sample was used directly to prepare bromide 6C without further purification. 9,24-Dibromo-8,15,23,30-tetramethyl[2.1.2.l]metacyclophane-1,16-dienes 6C (X= Y = CHBr). PBr3 (85 pL, 0.72 "01) was added to a suspension of the dialcohol6D (X = Y = CHOH) (17 mg, 0.036 mmol) in dry benzene (5 mL) under Nz at 20 "C. After stirring for 8 h, ether was added and the mixture was washed with H20,aqueous NaHC03,and H20,then was dried, and evaporated. The residue was fdtered through a short column of silica gel with pentanedichloromethane (1:l)as eluant, to give white crystals of dibromide 6C: 20 mg (92%),mp 247-249 "C sublimed; 'H NMR (90 MHz) 6 7.65-7.10 (m, Ar H), 7.00 (s, CH=CH), 6.90-6.60 (m, Ar H and CHBr), 2.47, 1.43, 1.18 (s, Ar CH,); IR (KBr) 1450,1372,1160,1080,960,800,782,718cm-'; MS (CI) MH', m/e 597 (40), 517 (loo), 438 (38). Anal. Calcd for CMH3J3r6 C, 68.24; H, 5.05. Found: C, 68.01; H, 5.00. 20,26-Dihydroxy-9,16,25,32-tetramethyl-2,18-dithia[3.1.3.l]metacyclophane 5C (X = Y = CHOH). A suspension of the diketone 5B (X = Y = CO) (456 mg,0.85 "01) and NaBH, (161 mg,4.25 "01) in wet THF (200mL) was heated under reflux for 12 h. After the mixture had cooled dilute aqueous HCl was added until the solution was acidic. The bulk of the solvent was then removed under reduced pressure and the residue was stirred with HzO (200 mL). The white crystals of dialcohol 5C were collected and dried to give 459 mg (100%): mp >350 "C; IR (KBr) 3400 (b, OH), 1460,1440,1228,1090,1074,1060,1010,808,776, 740 cm-'. This sample was used directly to prepare bromide 5D (X = Y = CHBr) below. 10,26-Dibromo-9,16,25,32-tetramethyl-2,18-dithia[3.1.3.1]metacyclophane 5D (X = Y = CHBr). PBr3 (0.14 mL, 1.5 mmol) was added to a suspension of crude dialcohol5C (X = Y = CHOH) (162 mg,0.3 "01) in dry benzene (150 mL) and stirred at 20 "C for 12 h. The mixture was then washed with HzO, aqueous NaHC03,and H20,then was dried, and evaporated. The residue was stirred with boiling dichloromethane (5 mL) for 15 min and hot filtered to give white crystals of dibromide 5D: 162 mg (81%);mp >350 "C; lH NMR (CD2C12,90 MHz) 6 7.33-6.54 (m, Ar H and CHBr), 4.24-3.34 (m, CH2S),2.13-1.04 (singlets, Ar CH,); MS (CI) MH+, m / e 665 (
