2,2'-disubstitutedamino-4-4'-bis-pyrimidines (3a-m) have been prepared by linking 2,4-dichloro-6-methyl-5-nitropyrimidine (1) with several diamines and subsequent reaction with suitable amines. some of these compounds (3c and 3j) which were reduced catalitically, on treatment with nitrous acid, urea in pyridine, and boiling thionyl chloride gave the corresponding bistriazolopyrimidin ...