Synthesis and Some Regularities of Transformations of 5,5-Dimethyl-3-(2-methylalyl)-2-thioxo-2,3,5,6-tetrahydrobenzo[h]quinazoline-4(1H)-one. Antibacterial Activity of the Obtained Compounds

Based on ethyl 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carboxylate (amino ester), a method for the synthesis of 5,5-dimethyl-3-(2-methylallyl)-2-thioxo-2,3,5,6-tetrahydrobenzo[h]quinazoline-4(1H)-one was developed. The latter was alkylated with halides of various structures, resulting in the production of 2-alkylsulfanyl-5,5-dimethyl-3-(2-methylallyl)-5, 6-dihydrobenzo[h]quinazoline-4(3H)-ones. By condensation of thioxobenzoquinazoline with hydrazine hydrate, 2-hydrazinyl-5,5-dimethyl-3-(2-methylallyl)-5,6-dihydrobenzo[h]quinazoline-4(3H)-one was synthesized, but similar reactions with 2-ethanolamine and 3-propanolamine proceeded abnormally with the formation of 2-(2-hydroxyethyl)amino-5,5-dimethyl-5,6-dihydrobenzo[h]quinazoline-4(3H)-one and 2-(3-hydroxypropyl)amino-5,5-dimethyl-5,6-dihydrobenzo[h]quinazoline-4(3H)-one, respectively. The interaction of the indicated thioxobenzoquinazoline with benzylamine proceeds with intramolecular cyclization with the formation of 6,6,10,10-tetramethyl-9,10-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazoline-7(6H)-one. The antibacterial properties of the synthesized compounds were studied. It was found that the studied compounds have antibacterial activity.