Preparation of new O-Alkyl naphthalenecarbothioates and alkyl naphthalenecarbodithioates, and EPR-spectroscopic study of their radical anions1,2

摘要

O-Alkyl naphthalenecarbothioates and bis-carbothioates are prepared by the reaction of the corresponding esters by use of Lawesson's reagent. The related naphthalenecarbodithioates are obtained (a) from methylnaphthalenes via bromination with NBS, subsequent methoxide-promoted reaction with sulfur, and finally alkylation of the carbodithioate salts with alkyl halides or (b) lithiation of bromonaphthalenes, reaction with carbon disulfide, and alkylation. The thiono- and dithioesters were transformed into persistent radical anions by in situ electroreduction. Spin density distributions were determined by EPR spectroscopy and MO calculations.