2H-Pyrimido(4,5-e)-1,2,4-thiadiazine-6,8(5H,7H)-dione, 5,7-dimethyl-, 1,1-dioxide 5,7-Dimethyl-1,2,4-pyrimido(4,5-e)thiadiazine-6,8-dione 1,1-dioxide 74039-28-4