C. Wei
Dec 15, 1986
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0
Influential Citations
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Citations
Journal
Acta Crystallographica Section C-crystal Structure Communications
Abstract
Structures of two isomeric compounds are reported: 4-phenyl-3H-1,2-dithiole-3-thione (4-PDT) and 5-phenyl-3H-1,2-dithiole-3-thione (5-PDT). Both have formula C6Hs.C3HS3, M r = 210.339, X-ray data collected with 2(Mo K~tl) = 0.7093 A at 296 (1) K. The former belongs to the monoclinic space group P2Jc, a = 17.827 (4), b = 5.731 (1), c= 9.272 (2)A, fl= 91.93(2) ° , V=946.8(3)A 3, Z=4, Dm=l.47(1), D x=l.475gcm -3, g=6-93cm -~, F(000)=432. Final R(F)=0.031 for 2255 counter data with Fo2___ 2a(Fo2). The latter crystallizes in the ortho- rhombic space group Pbca, a= 19.949 (6), b= 12.188 (3), c = 7.544 (2) A, V= 1834.2 (9) A 3, Z = 8, D m = 1.51 (1), D x = 1.523 gcm -3, g = 7.16 cm -1, F(000) = 864. Final R(F)= 0.031 for 1633 data with Fo 2 > 20(Fo2). The molecules are composed of a phenyl ring and a five-membered heterocyclic ring, the dif- ference between the two isomers being the positions of the C atom of the 3H-1,2-dithiole-3-thione ring to which the phenyl ring is linked. The two molecules have bond lengths and angles resembling each other and other compounds containing 3H- 1,2-ditb.iole-3-thione as a building unit. The phenyl rings and the five- membered-ring systems are both planar to within 0.01 A in both structures, the angle between the two plane normals being 67.40(9) ° for 4-PDT and 29.36 (8) ° for 5-PDT. Introduction. The title compounds, 4-PDT and 5-PDT, contain 3H-1,2-dithiole-3-thione as a building unit which was considered by Bueding, Dolan & Leroy (1982) to be essential for the antischistosomal drug 4-methyl-5-(2-pyrazinyl)-3H- 1,2-dithiole-3-thione (ol- tipraz) to function. In our previous studies, it was shown that the pyrazine ring is linked to 4-methyl- 3H-1,2-dithiole-3-thione via a C-C bond to yield oltipraz (Wei, 1983), or to 4-methyl-3H-1,2-dithiol- 3-one to form an oltipraz analog (Wei, 1985a). On the other hand, the 3H-1,2-dithiole-3-thione ring could be linked to a p-methoxyphenyl group, yielding 5-(p- methoxyphenyl)-3H-1,2-dithiole-3-thione (Wang, Lin & Wei, 1985). The present paper reports the structures in which a phenyl ring replaces an H atom of the 3H-1,2-dithiole-3-thione ring at two different positions. Thus, crystallographic elucidation of the stereo- chemistry of a variety of different compounds contain- ing the six- and five-membered-ring systems afford considerable stereochemical insight into the molecular parameters, including the angle between plane normals for the two ring systems. Experimental. Maroon crystals of 4-PDT were ob- tained from toluene solution and orange crystals of 5-PDT from ethyl acetate solution of the corresponding specimen, kindly furnished by Professor Ernest Bueding of The Johns Hopkins University. Crystal densities determined by flotation in mixtures of 2-bromobutyric acid and 1,2-dichloroethane. In each case, space group and approximate cell parameters established from Weissenberg and precession photographs. For 4-PDT,