Ammonia → 4-methyl-5-phenyl-3H-[1,3]oxazine-2,6-dione

Participants

Reaction Steps

Ethyl 2-phenylacetoacetate (1.0 g, 4.85 mmol) and urethane (0.43 g, 4.85 mmol) were heated, neat, with Phosphorous oxychloride (3 mL) at 90° C. for 3 hours. The excess reagents were removed under vacuum and the resulting residue was triturated with benzene and filtered. This solid was triturated with diethyl ether, filtered, and dried to yield 0.818 g (83%). MS (DCI/NH3) m/z 204 (M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 1.98 (s, 3 H) 7.28 (m, 2 H) 7.39 (m, 3 H) 11.65 (s, 1 H).

Provenance & Evidence