Chemistry of α‐(benzotriazol‐l‐yl)alkylpyridines. Unusual nucleophilic attack at c‐3a of the benzotriazolyl ring

Abstract

Lithiation of 2‐, 3‐ and 4‐[α‐(benzotriazol‐l‐yl)methyl]pyridines with butyllithium followed by reactions with electrophiles (alkyl halides, aldehydes, ethyl benzoate and diphenyl disulfide) gave the corresponding α‐sub‐stituted derivatives in good yields. Repetition of the reaction sequence allowed substitution of the second α‐proton by an electrophile. 2‐[α‐(Benzotriazol‐l‐yl)‐α‐(phenylthio)pentyl]pyridine thus obtained gave an unusual attack of the Grignard reagents at C‐3a of the benzotriazole system on treatment with arylmagnesium bromides. Copyright © 1994 Journal of Heterocyclic Chemistry