Dithiocarboxylation Reactions of N-Containing C-Nucleophiles

Abstract

3-Quinuclidinone reacts with carbon disulfide, strong base and an alkylating agent in dipolar aprotic solvents giving 2-dialkylthiomethylene compounds 1. N-ac-ceptor methyl substituted 2,2,N-trimethyl-propionamides afford in this procedure compounds 2-4 and the N-cyanomethyl-N-methyl-benzamide forms compounds 5. 2-Methyl-benzimidazole leads to the product of N-attack, whereas using 1,2-dibromoethane 1,1'-carbonothioyl-bis(2-methyl-benzimidazole) 6 is formed. 2-Chloro-N-cyanomethyl-N-methyl-benzamide 8 gives on treatment with 2 equivalents of a suitable base, carbon disulfide, and an alkylating agent at lower temperatures the expected substituted ketene dithioacetals 9. At higher temperature the 2-alkylthio-4-methyl-5-oxo-4,5-dihydrobenzo[f]-1,4-thiazepine-3-carbonitriles 10 are formed. Reaction products have been identified and structurally characterized by X-ray analysis.