Abstract: An interaction of 4-hydrazinoquinazoline with dicarboxylic acid anhydrides is investigated. Carrying out the reaction in mild conditions proper hydrazidoacids were synthesized. The reaction in the glacial acetic acid medium is accompanied with the cascade of tandem transformations because of dehydration of an above intermediate hydrazidoacids. Instead, the reaction of campharic, endic, phthalic anhydrides and its hydrogenated analogues with rigid framework carcass, results in the formation of proper imidoaminic structures. An interaction of 4-hydrazinoquinazoline with a succinic and glutaric acid anhydrides, and also the heterocyclization of monoethyl ether of oxalic acid 2-(4(3H)-quinazolinyliden)hydrazide is accompanied with the formation of 2-R-[1,2,4]triazolo[1,5-c]quinazolines via Dimroth-like rearrangement of the expected [4,3-c] series.