A convenient synthesis of 2-sulfanylbenzoselenazole derivatives via the reaction of 2-lithiophenyl isothiocyanates with selenium

摘要

The title compounds have been prepared from 2-bromophenyl isothiocyanates 1. Thus, 2-lithiophenyl isothiocyanates 2, obtained from 1 and BuLi through Br/Li exchange, reacted with Se at -78° to form lithium benzoselenazole-2- thiolates 3, which, upon aqueous workup, afforded benzoselenazole-2(3H)-thiones 4. The thiolates 3 were alkylated with reactive alkyl halides and acylated with carboxylic acid chlorides to give 2-(alkylsulfanyl)benzoselenazoles 5 and S-(benzoselenazol-2-yl) thiocarboxylates 6, respectively.