Synonyms: 2-(2-Chloroethyl)-2,3-dihydro-4H-1,3-benzoxazin-4-one;2-(2-Chloroethyl)-2H-1,3-benzoxazin-4(3H)-one;2-(2-Chloroethyl)-3,4-dihydro-2H-1,3-benzoxazin-4-one; 2-(b-Chloroethyl)-2,3-dihydro-4-oxo(benzo-1,3-oxazine);4-Oxo-2-(b-chloroethyl)-2,3-dihydrobenzo-1,3-oxazine;Ap 67; Apirazin; Chlorethylbenzmethoxazone; Chlorthenoxazine; NSC 525254;Ossapirina; Ossazone; Piroxina; Reumagrip; Valmorin; Valtorin