From haloquinolines and halopyridines to quinoline- and pyridinesulfonyl chlorides and sulfonamides

Abstract

The action of sodium methanethiolate (in boiling DMF) towards haloazines (i.e. chloro- or bromo-pyridines and quinolines) (1) (with halogen substituent in non-aza-activated position) causes sequentially halogen ipso-substitution to methylthioazines (2) and then S-demethylation to azinethiolates (3A), which were: i) subjected to S-methylation, ii) oxidized to diazinyl disulfides (4) and iii) oxidatively chlorinated to azinesulfonyl chlorides (5). α- and γ-pyridine- and quinolinesulfonyl chlorides (5a, 5c, 5d and 5f) were prepared by oxidative chlorination of respective disulfides (4) performed in conc. hydrochloric acid and characterized by 1H and 13C NMR spectra. All azinesulfonyl chlorides (5) were effectively converted to corresponding azinesulfonamides (6). © 2007 The Japan Institute of Heterocyclic Chemistry.