Synthesis and chemical transformations of partially hydrogenated [1,2,4]triazolo[5,1-b]quinazolines

The reaction of 5-methyl-7-phenyl-4,7-dihydro-1,2,4-triazolo1,5-a]pyrimidine with α,β-unsaturated carbonyl compounds in MeOH in the presence of MeONa affords partially hydrogenated aryl-substituted 1,2,4]triazolo5,1-b]quinazolines. Hydrolysis, oxidation, reduction, and alkylation of 5,6,8-triphenyl-5,6,7,10-tetrahydro1,2,4]triazolo5,1-b]quinazoline were studied. The structure of one oxidation product, viz., 7-hydroxy-5,6,8-triphenyl-6,7-dihydro1,2,4]triazolo5,1-b]quinazoline, was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 335—340, February, 2006.