Unfused heterobicycles as amplifiers of phleomycin. IV. 4,5'-Bipyrimidines with dimethylamino and/or dimethylaminoethylamino substituents

Abstract

The reaction of 5-bromo-N,N-dimethylpyrimidin-2-amine (1a) with butyllithium gives N,N,N',N'-tetramethyl-4,5'-bipyrimidine-2,2'-diamine (2a). The known 4',6-dimethoxy derivative (3a) of this gives only 2,2'-bis(dimethylamino)-6-methoxy-4,5'-bipyrimidin-4'-one (4) on attempted aminolysis by 2-dimethylaminoethylamine, but the corresponding bismethylthio substrate (3b) does undergo regular aminolysis at the 4'-position to give the required product (34.2,2',4',6-Tetrakismethylthio-4,5'-bipyrimidine (5a) undergoes similar aminolysis, first at the 4'- and then at the 2'-position, to give the appropriate amines (5b) and (5c). Structures are confirmed by n.m.r. and mass spectral studies. The products showed little activity as amplifiers of phleomycin.