| abstract |
2,4-Diamino-pyrimidines of the formula I <IMAGE> (R1-3 = H, alkyl, alkoxy, aralkoxy, alkylthio or two = alkylenedioxy) and their salts are prepared by reacting a compound of formula II <IMAGE> with guanidine or a salt thereof. The starting materials are prepared by reacting the corresponding compound in which the m-phenylenediamine residue is replaced by a piperazine ring with m-phenylenediamine, and the piperazine derivatives are prepared by reacting the corresponding aldehyde with N,N'-bis-(cyanoethyl)piperazine. |