Sh. Sh. Dashyan

Synthesis of Condensed 3-Cyanopyridin-2(1H)-ones Based on the Smiles Rearrangement

Condensed 3-cyanopyridin-2(1H)-ones have been synthesized via an intramolecular nucleophilic substitution (Smiles rearrangement). The X-ray structural analysis revealed the existence of intermolecular hydrogen bonding.

Synthesis and neurotropic activity of 6,8-diamino derivatives of pyrano[3,4-c]pyridines

New diamino derivatives of pyrano[3,4-c]pyridines were synthesized by the pyridine ring recyclization. The presence of the intramolecular hydrogen bond in 6-[(4-methoxyphenyl)amino]-3,3-dimethyl8-methylamino-3,4-dihydro-1H-pyrano[3,4-c]pyridin-5-carbonitrile was identified by X-ray diffraction. A pharmacological study of the synthesized compounds was carried out in known tests, such as assay for antagonism induced by corazole subcutaneous injection and the open field test. The method of rotating rod was used to evaluate neurotoxicity. The diamino derivatives of pyrano[3,4-c]pyridines were found to possess neutrotropic properties. The synthesized compounds, as well as diazepam, prevent the occurrence of clonic seizures and clonic corazoleinduced convulsions in animals; however, they cause a behavior-depressing sedative effect.

Synthesis and Anticonvulsive Activity of 5-Pyrrolidin-1-Ylpyrano[4″,3″:4′,5′]Pyrido-3′,2′:4,5]Thieno[3,2-D]Pyrimidine Derivatives

A method for preparing the amino, alkoxy, and alkylsulfanyl derivatives of pyrano[4″,3″:4′,5′]pyrido-[3′,2′:4,5]thieno[3,2-d]pyrimidines based on 8-chloro-2,2-dimethyl-5-pyrrolidin-1-yl-1,4-dihydro-2H-pyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine was developed. The anticonvulsant activity of the compounds synthesized here was investigated.

Synthesis and antibacterial activity of N-amino-derivatives of condensed pyridines

A method based on condensed 4-cyanopyridinethiones using O-tosylhydroxylamine as the aminating agent was developed for preparing tosylates of N-amino-derivatives of pyrano[3,4-c]pyridines; 5,6,7,8-tetrahydroisoquinolines; and cyclopenta[c]pyridines. The antibacterial activity of the synthesized compounds was assessed.

Synthesis and Neurotropic Activity of Amino Derivatives of Cyclopenta[4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d ]pyrimidines and Pyrimido[4′,5′:4,5]thieno[2,3-c]isoquinolines

Amethod for synthesizing amino derivatives of cyclopenta[4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine and pyrimido[4′,5′:4,5]thieno[2,3-c]isoquinoline from thieno[3,2-d]pyrimidine derivatives was elaborated. The neurotropic activity of the synthesized compounds was studied.

Synthesis of (Piperidin-1-yl)trihydropyrano(cyclopenta)- (4',5')pyrido(3',2' : 4,5)thieno(3,2-e)(1,2,4)triazolo- (4,3-c(1,5-c))pyrimidines

Reactions of 3-cyanopyridine-2(1H)-thiones with ethyl chloroacetate and chloroacetamide gave the corresponding amino-substituted thieno[2,3-b]pyridines which were treated with formamide or ethyl formate to obtain fused pyridothieno[3,2-d]pyrimidinones. The latter were converted into hydrazino derivatives whose cyclocondensation with triethyl orthoformate or formic acid afforded 7,10-dihydro-8H-pyranopyridothienopyrimidines and 2,3-dihydro-1H-cyclopentapyridothienopyrimidines annulated by triazole ring at the pyrimidine ring.

2-Allyloxy/propargyloxypyridines: synthesis, structure, and biological activity

The alkylation (allylation and propargylation) of 3-cyano-6-dialkylamino-2-pyridones containing a d-annulated ring occurs at the oxygen atom. The structures of the starting compounds and their alkylation products were determined by X-ray diffraction. The neurotropic and antimicrobial activity of alkylation products was examined.

Azido–tetrazole tautomerism of pyrano[3,4- c ]pyridine derivatives

Treatment of N-aryl-8-hydrazinylpyrano[3,4-c]pyridine-5-carbonitriles with sodium nitrite in acetic acid afforded the corresponding 8-azido derivatives existing in solution as equilibrium mixtures with cyclic tetrazole tautomer whose fraction attains 48%. Lower solvent polarity and elevated temperature favor increased fraction of the azido tautomer.

Synthesis and neurotropic activity of the derivatives of fused triazolo[4,3-c]- and triazolo[1,5-c]pyrimidines

The methods for preparation of fused triazolo[4,3-c]- and triazolo[1,5-c]pyrimidines were developed. The Dimroth rearrangement of these systems was studied. Pharmacological investigation of the synthesized compounds was conducted in known tests, such as antagonism with subcutaneous administration of corazole and the open-field test. The rotating rod method was used to assess the neurotoxicity. Neurotropic properties were found in many derivatives of triazolopyrimidine. They, like diazepam, prevent the occurrence of clonic twitching and corazole-induced clonic convulsions in animals. All selected compounds as well as diazepam exhibit an anxiolytic effect.

Synthesis of 5,8-Diamino-Substituted Pyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidines and Pyrimido[4′,5′:4,5]thieno[2,3-c]isoquinolines

Ethyl 1-amino-8,8-dimethyl-5-(piperidin-1-yl)-8,9-dihydro-6H-pyrano[4,3-d]thieno[2,3-b]pyridine-2-carboxylate and ethyl 1-amino-5-(piperidin-1-yl)-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxylate reacted with benzoyl isothiocyanate to give the corresponding 1-thioureido derivatives which underwent cyclization to 2,2-dimethyl-5-(piperidin-1-yl)-10-thioxo-1,4,10,11-tetrahydro-2H-pyrano[4″,3″:4′,5′]pyrido-[3′,2′:4,5]thieno[3,2-d]pyrimidin-8(9H)-one and 5-(piperidin-1-yl)-10-thioxo-1,2,3,4,10,11-hexahydropyrimido-[4′,5′:4,5]thieno[2,3-c]isoquinolin-8(9H)-one. The cyclization products were converted into 8-chloro derivatives, and the chlorine atom therein was replaced by various amines.