2-Ethoxy-6-(4-morpholinyl)-4,4-bis(trifluoromethyl)-4H-1,3,5-oxadiazine AIDS-146121 AIDS146121 Ethyl 6-(4-morpholinyl)-4,4-bis(trifluoromethyl)-4H-1,3,5-oxadiazin-2-yl ether NSC672101