Pyridines. Partie X¹ ‐ Synthèse de Pyridyl‐ et Quinolylenamidines par Condensation Entre Composes Organolithiens et Benzonitrile. Nouveaux Intermediaires pour Réactions D'Heterocyclisation

Abstract

Abstract A series of methylpyridyl‐ and (methyl) quinolylphenylvinylbenzamidines has been synthesized by condensation of organopolylithium compounds derived from polymethylpyridines and ‐quinolines with benzonitrile. In diethyl ether, beside the enamidines, the reaction gives enolizable ketones. Triphenylimidazole, triphenyl‐s‐triazine and triphenylpyrimidine are isolated in the case of benzylmagnesium chloride. Possible routes leading to the various products are suggested. In diethyl ether, the conditions which give the enamidine derivatives in useful yields have been established. In liquid ammonia, on the contrary, no polycondensed products were isolated. The intermediate enamine and enamidine anions are trapped in diethyl ether by acylation of the reaction mixture before hydrolysis. With benzoyl or acetyl chloride, ethyl chloroformate, various C‐ and N‐acylated products (enolizable β‐diketones, enamides, acylenamides, N‐acylenamidines) and their cyclization products (pyrimidines) are obtained. The latter are also prepared from the isolated enamidines and benzoyl chloride.