Abstract
New functionalized 7,9-dimethylpyrimido[4,5-d][1,2,4]triazolo[4,3-a]pyrimidine-5,6,8(1H,7H,9H)-trione derivatives were synthesized via reaction of the hydrazonoyl halides with 7,8-dihydro-1,3-dimethyl-7-thioxopyrimido[4,5-d]pyrimidine-2,4,5(1H,3H,6H)trione. The biological activity of the products has been evaluated. The mechanism and the regioselectivity of the studied reactions have been discussed.