Vladimir I. Musatov

Synthesis of partially hydrogenated 1,2,4-triazoloquinazolines by condensation of 3,5-diamino-1,2,4-triazole with aromatic aldehydes and dimedone

Three-component condensation of 3,5-diamino-1,2,4-triazole with aromatic aldehydes and dimedone in dimethylformamide gives 2-amino-5-aryl-8,8-dimethyl-5,6,7,8,9,10-hexahydro[1,2,4]triazolo[3,2-b]quinazolin-6-ones. The reaction of 3,5-diamino-1,2,4-triazole with dimedone in the absence of aldehyde involves dimethylformamide as one of the carbonyl components to afford 2-amino-8,8-dimethyl-6,7,8,9-tetrahydro[1,2,4]triazolo[2,3-a]quinazolin-6-one.

Diversity oriented heterocyclizations of pyruvic acids, aldehydes and 5-amino-N -aryl-1H -pyrazole-4-carboxamides: catalytic and temperature control of chemoselectivity

Heterocyclization reactions of pyruvic acids, aromatic aldehydes and 5-amino-N-aryl-1H-pyrazole-4-carboxamides yielding four different types of final compounds are described. The reactions involving arylidenpyruvic acids lead with high degree of selectivity to either 4,7-dihydropyrazolo[1,5-a]pyrimidine-5-carboxylic acids or 5-[(2-oxo-2,5-dihydrofuran-3-yl)amino]-1H-pyrazoles, depending on the catalyst type or temperature regime. The interactions based on arylpyruvic acids can take place under kinetic or thermodynamic control producing 7-hydroxy-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-7-carboxylic acids or 3-hydroxy-1-(1H-pyrazol-5-yl)-1,5-dihydro-2H-pyrrol-2-ones, respectively.

An easy access to 2-Amino-5,6-dihydro-3H-pyrimidin-4-one building blocks: The reaction under conventional and microwave conditions

SummaryA new one-stage fast multicomponent synthesis of title compounds leads to products in 21–55% isolated yields under both conventional and microwave conditions. The primary amino group in the building blocks can be easily acylated by various usual electophilic agents that can be utilized in the synthesis of diverse heterocylic compounds libraries.

Cascade cyclization of 3(5)-aminopyrazoles with aromatic aldehydes and cyclohexanediones

Three-component condensation of 5(3)-amino-3(5)-methylpyrazole with aromatic aldehydes and 1,3-cyclohexanedione afforded mixtures of 3-methyl-4-aryl-2,4,6,7,8,9-hexa hydro-5H-pyrazolo[3,4-b]quinolin-5-ones and 2-methyl-9-aryl-5,6,7,9-tetrahydro pyrazolo[5,1-b]quinazolin-8(4H)-ones. The reaction of 3-aminopyrazolo-4-carbonitrile and ethyl 3-aminopyrazolo-4-carboxylate with aldehydes and cyclo hexanedione or dimedome is regioselective and leads to the formation of partially hydrogenated pyrazolo [5,1-b]quinazolin-8-one systems. In all compounds the dihydroazine ring exists in the enamine tautomeric form.

Generation of 500-member library of 10-alkyl-2-R(1),3-R(2)-4,10-dihydrobenzo[4,5]imidazo[1,2-alpha]pyrimidin-4-ones.

Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo Dihydrobenzo[4,5]imidazo[1,2-a]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member library of the title compounds.

Chemical Reactions of 2-Methyl-5,7-diphenyl-6,7-dihydropyrazolo[1,5-a]pyrimidine

The hydrolysis, oxidation, reduction, alkylation, formylation, and nitrosation reactions of 2-methyl-5,7-diphenyl-6,7-dihydropyrazolo[1,5-a]pyrimidine have been studied.

Multicomponent Reaction of 2-aminobenzimidazole, Arylglyoxals, and 1,3-cyclohexanedione

Three-component reactions of 2-aminobenzimidazole with arylglyoxals and 1,3-cyclohexanedione have been studied under conventional heating and microwave irradiation. Different product types including the Michael adduct and fused heterocyclic systems were obtained. Conditions for the selective formation of 12-aroylbenzimidazo[2,1-b]quinazolin-1(2H)-ones and 3-oxo-2-(2-aryl-1H-imidazo[1,2-a]-benzimidazol-9-ium-3-yl)cyclohex-1-enolates have been determined. The structures of all compound types were established by an X-ray diffraction study.

Cyclocondensation of 3(5)-Aminopyrazoles with Arylglyoxals and Cyclohexane-1,3-diones

Partly hydrogenated 4-aroyl-substituted pyrazolo[3,4-b]quinolin-5-ones and 5-aroyl-substituted pyrazolo[1,5-a]quinazolin-6-ones were obtained by three-component cyclocondensation of substituted 3(5)-aminopyrazoles with the arylglyoxal hydrates and dimedone, 1,3-cyclohexanedione, or 4,4-dimethylcyclohexanedione in an alcohol medium. The chemical transformations of pyrazolo[3,4-b]quinolin5-ones in reactions with hydrazine hydrate and also upon alkylation, acylation, and oxidation were studied.

α,β-Unsaturated ketones based on allobetulone

Crotonization of allobetulone with aromatic and heteroaromatic aldehydes gave a number of new α,β-unsaturated ketones of the lupane series, and their steric structure was determined by X-ray analysis of (E)-4-[(3-oxoallobetulan-2-ylidene)methyl]benzonitrile as an example.

Cascade cyclization of 1,2-diamino-4-phenylimidazole with aromatic aldehydes and cyclohexanediones

The three-component condensation of 1,2-diamino-4-phenylimidazole with aromatic aldehydes and 1,3-cyclohexanediones occurred regioselectively and afforded 3-amino-1-phenyl-10-aryl-7,8-dihydroimidazo[1,5-b] cinnolin-9(5H,6H,10H)-ones.