Twenty-four derivatives of 4-(2-dialkylamino-1-phenylethyl)-2H-pyrido [3, 2-b]-1, 4-oxazin-3-one (8a-13d) were synthesized, and then obtained as hydrochloride. The following results were obtained by the preliminary investigation on the local anesthetic and the analgesic (mouse writhing test) activities of these synthesized compounds. All these compounds had no surface anesthetic activity, and weaker infiltrative one than that of lidocaine ; the analgesic action of almost all these compounds was superior to that of aspirin.
