1.3- Dihydro-2/7-imidazo pyridine-2-thiones

Numereous derivatives of benzimidazole, naphthoimidazoles and other condensed imidazole systems can be very effectively thiated with elemental sulfur on heating without solvent at 230-260°C. The product of this reaction is the corresponding imidazolin-2-thione formed in excellent yield (67ZOR1518, 95IZV2231). For example, imidazo[4,5-cjpyridines (329, R =H, Aik, Ar, C6H5CH2) gave 1,3-dihydro-2//-imidazo[4,5-c]pyridine-2-thiones (330). 

C13H11CIN2O2 f 3-(p-Chlorophenyl)-6-methyl-2-oxo-2,3,3a,7a-tetrahyd-ro-oxazolo[4,5-b]pyridine, 45B, 403 Cl3H11CIN2O2, 3-(p-Chlorophenyl)-7a-methyl-2-oxo-2,3,3a,7a-tetrahyd-ro-oxazolo[4,5-b]pyridine, 45B, 403 C13H12N2O5, 1-Ethyl-1,4-dihydro-4-oxo-5-amino-6,7-methylenedioxy-3-quinoline-carboxylic acid, 42B, 277 C13H13CIN2O3S, 1-p-Chlorophenyl-4-(a-D-erythrofuranosyl)-4-imidazo-line-2-thione, 40B, 332... 

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