Rearrangement of 2-amino-1-aryl-1,4-dihydropyridines

Heating of 2-amino-1-aryl-1,4-dihydropyridines in acidic aqueous media gives 2-arylamino-1,4-dihydropyridines. The reaction formally involves the migration of the aryl substituent from the endo-to exocyclic N atom. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1260, July, 2006.     

Interaction of 5-Aryl-2,3-dihydrofuran-2,3-diones with Functionally Substituted Hydrazides and Diaminoglyoxal Diphenylhydrazone

The reaction of 5-aryl-2,3-dihydrofuran-2,3-diones with cyanoacetylhydrazide, o-(hydrazinocarbonyl)phenylthiourea, and the diphenylhydrazone of diaminoglyoxal leads to the synthesis of the corresponding N-cyanoacetylhydrazides of aroylpyruvic acids, 2-(N-aroylpyruvoylhydrazinocarbonyl)-phenylthioureas, and 5,6-bis(phenylhydrazono)-3-aroylmethylenepiperazin-2-ones. The results of the primary investigation of the biological activity of N-cyanoacetylhydrazides of aroylpyruvic acids are given.     

Recyclization on Condensation of Alkylhydrazones of 2-Phenacyl-1H-Benzimidazole with Acylating Agents

Cyanoethyl-, ethyl-, and methylhydrazones of 2-phenacyl-1H-benzimidazole undergo recyclization on condensation with aroyl chlorides or dimethylformamide with the formation of 5-(o-aroyl-aminoanilino)pyrazoles or 1-(5-pyrazolyl)-1H-benzimidazoles. The reaction with aroyl chlorides occurs selectively only with the corresponding cyanoethylhydrazone.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 372–378, March, 2005.     

Reactions of immonium and telluronium salts of 2-phenylbenzotellurazole

N-methyl-2-phenylbenzotellurazolinium iodide, like other N-methylbenzochalcogenazolium salts, readily undergoes reduction, hydrolysis, and recyclization with hydrazine hydrate and o-phenylene diamine. 1-Methyl-2-phenylbenzotelluronioazole perchlorate is an effective methylating agent in reactions with nucleophiles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1268–1272, August, 2007.     

Mechanism of the recyclization of 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one into derivatives of 2-amino-5-benzylidene-1,5-dihydro-4H-imidazol-4-one

Mechanisms are given for reactions taking place upon heating 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one in a medium consisting of a secondary amine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 111–114, January, 2008.     

The Use of Microwave Activation in the Chemistry of Heterocyclic Compounds. (Review)

Published data on the successful application of microwave activation in the chemistry of various heterocycles over the last two years are discussed.     

A new direction in the alkylation of 5‐acetyl‐2‐amino‐6‐methyl‐4‐phenyl‐4H‐pyran‐3‐carbonitrile with active methylene reagents

In this paper, we report a new synthesis route to 4H‐pyran derivatives and a plausible reaction mechanism. The interaction of 5‐acetyl‐2‐amino‐6‐methyl‐4‐phenyl‐4H‐pyran‐3‐carbonitrile with different active methylene reagents gives rise to the cleavage and subsequent recyclization of the pyran ring to afford the corresponding 4H‐pyran derivatives.