4-(5-Ethyl-2-(2-pyridinyl)-3,6-dihydro-2H-1,2-oxazin-6-yl)phenyl methyl ether 5-Ethyl-6-(4-methoxyphenyl)-2-(2-pyridinyl)-3,6-dihydro-2H-1,2-oxazine AIDS-137134 AIDS137134 NSC640883