1,3,4-Thiadiazolo(3',2':1,2)pyrimido(5,4-b)indol-5(6H)-one, 2-(2-ethoxyphenyl)- 116989-25-4 2-(2-Ethoxyphenyl)-1,3,4-thiadiazolo(3',2':1,2)pyrimido(5,4-b)indol-5(6H)-one