Pyrimido4,5-e(1,2,4)-triazolo3,4-b(1,3,4)-thiadiazine-7,9(6H8H)-diones

摘要

Some 5H-pyrimido4,5-e(1,2,4)-triazolo3,4-b(1,3,4)-thiadiazine-7,9-(6H,8H)-diones (4 a–d) have been synthesised by the condensation of 3-alkyl-4-amino-5-mercapto-(1,2,4)-triazoles (1 a–d) with 5-bromobarbituric acid (2a). Similarly some 9a-nitro-5H-pyrimido4,5-e(1,2,4)-triazolo3,4-b(1,3,4)-thiadiazine-7,9(8H,9aH)-diones (5 a–d) have been obtained by the condensation of1 a–dwith 5-bromo-5-nitrobarbituric acid (2b) and final cyclisation withPPA. The structures have been confirmed by PMR spectra and analytical