2H-benzimidazoles (isobenzimidazoles). Part 6. Sulfur derivatives

Abstract

The products obtained by treating 2H-benzimidazole-2-spirocyclohexane 1 or its 5-chloro derivative 9 with various thiols (PrSNa, Bu^tSNa, PhSNa, pyridine-2-thiol, or pyrimidine-2-thiol) depend on the reaction conditions. Monosubstitution is possible and any number of alkylthio groups can be introduced up to four.

5-Phenylsulfonyl-, 18 and 5-nitro-2H-benzimidazole-2-spirocyclohexane 10 react with pyridine-2-thiol or pyrimidine-2-thiol in position-4 whilst the 5-(pyridin-2-ylthio) derivative 16 reacts with sodium benzenesulfinate in position-6. In all cases the products isolated were the 1,3-dihydrocompounds 26, 38, 39 or 21, respectively.