The preparation of substituted oxazole by condensation of
O
‐acylacylion with ammonia or ammonium acetate is known as Davidson oxazole cyclization. This reaction is found most suitable for 2,4,5‐trisubstituted oxazole or oxazoles with an aromatic substituent at C‐5,whereas it works poorly for the preparation of 2,4‐disubstituted or monosubstituted oxazoles. The study finds that the cyclization to form oxazole does not occur when ammonia or ammonium acetate is replaced by organic amines.