Oxidation and bimolecular condensation reactions of 2-alkyliminocyclopentanedithiocarboxylic acids, 2-oxocyclopentanedithiocarboxylic acids, and 3-methyl-5-oxo-1-phenyl-Δ2-pyrazoline-4-dithiocarboxylic acid
Abstract
The 2-oxocyclopentanedithiocarboxylic acids (9) and (10) and 3-methyl-5-oxo-1-phenyl-Δ2-pyrazoline-4-dithiocarboxylic acid (13), on oxidation, gave the 3,5-bis-(2-oxocyclopentylidene)-1,2,4-trithioles (11) and (12) and 3,5-bis-(3-methyl-5-oxo-1-phenyl-Δ2-pyrazolin-4-ylidene)-1,2,4-trithiole (14), respectively. The 2-alkyliminocyclopentanedithiocarboxylic acids (1)–(4), under similar conditions, underwent normal oxidation to the bis-(2-alkyliminocyclopentylthiocarbonyl) disulphides (5)–(8). The acid (9) afforded 6,7-dihydro-2-(2-oxocyclopentylidene)cyclopenta[d][1,3]dithiin-4(5H)-thione (15) when treated with dimethylformamide alone, and 2,4-bis-(2-oxocyclopentylidene)-1,3-dithietan (16) when treated with dimethylformamide and an acyl chloride. 2,4-Bis-(3-methyl-5-oxo-1-phenyl-Δ2-pyrazolin-4-ylidene)-1,3-dithietan (17) was likewise obtained from the acid (13).