One-pot synthesis of 2-sulfanyl-3-sulfinyl(or sulfonyl)-1H-indoles via cyclization of 1-isothiocyanato-2-[sulfinyl(or sulfonyl)methyl]benzenes with sodium hydride

An efficient one-pot method for the synthesis of 2-sulfanyl-3-sulfinyl(or sulfonyl)-1H-indoles from 1-isothiocyanato-2-[sulfinyl(or sulfonyl)methyl]benzenes, derived from N-[2-(chloromethyl)phenyl]formamide by an easy four-step sequence, has been developed. The products are formed via cyclization of the precursor isothiocyanates using 2 equiv of sodium hydride followed by S- and/or N-alkylation of the resulting 1-sodio-2-sodiosulfanyl-1H-indole intermediates.