Abstract Stepwise conversion of pyrimidin-2 (1H)-one to 2-amino-5-aryloxazoles via oxazolo [3, 2-a] pyrimidinium salts is reported. The sequence involves,(i) regioselective N-alkylation of pyrimidone by phenacyl bromides,(ii) cyclization of obtained 1-(2-aryl-2-oxoethyl)