Syntheses of Methylpyridine Derivatives. XXVI. Ring-Closure Reaction of 3-Acylamido-4-chloro-2, 6-lutidine with Potassium Amide in Liquid Ammonia

Abstract

Reaction of 3-acylamido-4-chloro-2, 6-lutidine (Ia-d) with KNH₂ in liq. NH₃ was carried out and 3-acetamido-(Ia) and 3-benzamido-4-chloro-2, 6-lutidine (Ib) were converted into the oxazolopyridine derivatives (II and V) and 3-acylamido-4-amino-2, 6-lutidine (III and VI), respectively. Similar reaction of 3-phenylacetamido-(Ic) and 3-acetoacetamido-4-chloro-2, 6-lutidine (Id) gave the oxazolopyridine derivatives (VII and XIV) and the pyrrolinopyridine derivatives (VIII and XV), respectively. Acylation of VIII afforded 6-acetyl derivatives (X), and methylation of VIII with methyl iodide gave 1, 3, 5, 7-tetramethyl derivatives (IX). Catalytic reduction of XV with platinum afforded 3-ethyl-3-hydroxy derivatives (XVIII).