Synthesis of 2,4-diaminoquinazoline derivatives

A series of 6- and 7-substituted derivatives of 2-(N,N-diethylamino)-4-(N,N-dimethylamino)quinazoline have been synthesized. The synthesis consists in converting N-phenyl-N',N'-diethylurea into chloroamidines which are treated with N,N-dimethylcyanamide to 1-chloro-2,4-diaza-1,3-butadiene derivatives, followed by a cyclization to quinazoline derivatives.