Quinones. Part 9. Side-chain alkylthiolation of methyl-1,4-naphthoquinones

Abstract

2-Methyl-1,4-naphthoquinones react with an excess of sodium methanethiolate to give methylthiomethyl derivatives. Corresponding products were obtained, but in lower yield, using α-toluene- and toluene-p-thiolates. With 3-chloro-2-methyl-1,4-naphthoquinone and methanethiolate, replacement of chlorine occurs before reaction with the side chain, while the minor products formed provide evidence that the side-chain alkylthiolation proceeds by addition of thiolate to the tautomeric quinone methide form of the methylquinone.