Reaction of β-Aminocrotonamide with N-Acylated Amino Acid Esters to give 2-Acylaminoalkyl-6-methylpyrimidin-4 (3H)-ones and Their Ring Closure with Polyphosphoric Acid (PPA)

Abstract

Reaction of β-aminocrotonamide with N-acylated amino acid esters in the presence of sodium methoxide gave 2-acylaminoalkyl-6-methylpyrimidin-4 (3H)-ones, some of which, on treatment with polyphosphoric acid (PPA), were transformed into imidazo [1, 5-a] pyrimidines and imidazo [4, 5-b] pyridines.