Fused pyrimidines. Synthesis of new derivatives of potential diuretic activity.

Certain derivatives of quinazoline and its bioisostere pyridopyrimidine carrying important structural features that contribute to diuretic activity, such as sulfonamido, morpholino and chlorophenyl, were prepared as potential diuretic agents. Likewise, some tricyclic 1,2,4-triazolo[3,4-b]quinazolines and pyrido[3,2-d][1,2,4]triazolo[4,3-alpha] pyrimidines with the same features were reported. Nine compounds were tested for the diuretic activity in rats and the results showed that the active compound is 7-chloro-2-methyl-3-phthalimido-4(3H)-quinazoline (4).