3-Benzyl-2,2-dioxo-6-phenyl-2,3-dihydro-1H-2.lambda.6-thieno[3,2-c][1,2,6]thiadiazin-4-one 3-Benzyl-6-phenyl-thieno[3,2-c][1,2,6]thiadiazin-4(3H)-one 2,2-dioxide AIDS-104967 AIDS104967