CONVERSIONS OF 2-AMINOPYRIDINES INTO 5-SUBSTITUTED DERIVATIVES MEDIATED BY 1-HYDROXYMETHYLBENZOTRIAZOLE

2-Aminopyridines are benzotriazolylmethylated at the 5-position by 1-h ydroxymethylbenzotriazole. The emthylene group of 2-amino-5-(benzotria zolylmethyl)pyridines 6 can he mono- or di-lithiated and subsequently substituted by various electrophiles. The benzotriazole moiety in both the primary products 6, and in their methylene-substituted derivative s 8 and 9, is displaced by alkyl and aryl anions derived from Grignard reagents, or by alkoxide and thioalkoxide anions. Moreover, the:deriv ative 8a undergoes smooth elimination of benzotriazole; under basic co nditions to generate the 5-vinyl-substituted 2-aminopyridine 12. These approaches allow the synthesis of many new types of 5-substituted 2-a minopyridines.