Lebedyeva I. Lebedyeva I. O. Cyclocondensing ability of substituted dihydropyrimidin-2-ones (thiones) and Biginelli reaction

The work is dedicated to the study of the cyclocondensing processes that lead to the formation of new heterocyclic systems derived from pyrimidine; regioselectivity of the formation processes of new pyrimido[4,5-d]pyridazin-2,5-diones, pyrrolo [3,4-d]pyrimidine-2,5-diones, thiazolo[3,2-a]pyrimidines and their bis-analogs. As a result of a multistage regioselected synthesis the heterocyclic derivatives of 2H-pyrimido[5',4':5,6][1,3]diazepino[2,1-f]purine-1,3,7,10(4H,6H,9H,11H)-tetrones that simultaneously contain structural fragments of pyrimidine, purine, 1,3-diazepine were obtained. In the work the results of the series of condensations that lead to the formation of novel annelated heterocyclic systems that contain pharmacophore groups, hence, fit the screening requirements of biologically active compounds have been shown. It has been established that during the process of synthesis of ilidenesubstituted dihydrothiazolo[3,2-a]pyrimidines, the dihydropyrimidine cycle undergoes hydrolyses and is followed by the formation of effective aldose reductase inhibitors - 5-arylidene-2,4-thiazolidinediones. In the work the factors that influence the direction of the condensation passage have been analyzed, the mechanisms of the intermolecular processes have been proposed and the structures of the intermediate and final reaction products have been identified. The biological activity spectrum of dihydropyrimidine derivatives and its dependence on pharmacophore groups' nature, introduced in the basis structure, has been studied.