ON THE REACTION OF BENZOHYDROXAMIC ACIDS WITH LAWESSON'S REAGENT

Abstract

Reaction of Lawesson's Reagent (LR) with two N-alkyl benzohydroxamic acids is presented. In addition to the desired thiohydroxamic acids 2, the reduction process provides amides 3 and thioamides 4. An unexpectedly pronounced solvent effect on the course of the reaction was observed. The best yields (40–50%) of 2a were obtained in THF, and in this solvent amide 3a was not formed. In HMPA solution the amide 3a and the thioamide 4a were the only products, and 2a was not formed at all.