Synthesis of trichloromethylpyrimidines and trichloromethylpyrimido-[4,5-d]pyrimidines from alkyl 2-(diaminomethylidene)-3-oxobutyrates and trichloroacetonitrile

摘要

Heterocyclization of alkyl 2-(diaminomethylidene)-3-oxobutyrates with trichloroacetonitrile yields alkyl 4-amino-6-methyl-2-trichloromethylpyrimidine-5-carboxylates. The latter compounds react with aryl isocyanates to produce the corresponding pyrimidinylureas, which undergo cyclization to 3-aryl-5-methyl-7-trichloromethylpyrimido[4,5-d]pyrimidine-2,4(1H,3H)-diones under the action of MeONa in MeOH.