AIDS-020871 AIDS020871 Carbamic acid,5-amino-3-(4'-azidophenyl)-2H-pyrido[4,3- b][1,4]oxazin-7-yl,ethyl ester, mixture [93:7] with carbamic acid,5-amino-3-(4'-chlorophenyl)-2H-pyrido[4,3- b][1,4]oxazin-7-yl,ethyl ester, ace tate, hydrate, hydrochloride