Synthesis and chemical properties of 3-acyl- and 3-carbethoxy-4-pyrones

Реакция 1-арил-2-диметиламинометиленбутан-1,3-дионов с диэтиоксалатом в присутствии гидрида натрия в ТГФ приводит к образованию этил 5-ароил-4-оксо-4Н-пиран-2- карбоксилатам, из которых 4-оксо-6-арил-4Н-пиран-2-карбоновые кислота (6- арилкомановая кислота) были получены с высоким выходом через кислотно катализируемую перегруппировку, сопровождаемую деформилированием. 5-Ароил-4- оксо-4Н-пиран-2-карбоновые кислоты (5-ароилкомановые кислоты) были синтезированы с помощью последовательности реакций раскрытия/закрытия пиронового цикла обработкой 5-ароил-2-карбэтокси-4-пирона пиперидином с последующим омылением и подкислением. Аналогично взаимодействие этил 2-диметиламинометилен-3-оксобутаноат с диэтилоксалатом в присутствии гидрида натрия в тетрагидрофуране приводит к диэтил 4- оксо-4Н-пиран-2,5-дикарбоксилату, из которого 4-оксо-4Н-пиран-2,5-дикарбоновая и 4- оксо-1-фенил-1,4-дигидропиридин-2,5-дикарбоновая кислоты и их производные с хорошим выходом.The reaction of 1-aryl-2-(dimethylaminomethylene)butane-1,3-diones with diethyl oxalate in the presence of sodium hydride in THF gave ethyl 5-aroyl-4-oxo-4H-pyran-2-carboxylates, from which 4-oxo-6-aryl-4H-pyran-2-carboxylic acids (6-arylcomanic acids) were obtained in high yields via acid-catalyzed deformylative rearrangement. 5-Aroyl-4-oxo-4H-pyran-2-carboxylic acids (5-aroylcomanic acids) were prepared via а ring-opening/ring-closure sequence by the reaction of 5-aroyl-2-carbethoxy-4-pyrones with piperidine and subsequent basic hydrolysis and acidification. And the reaction of ethyl 2-(dimethylamino)methylene-3-oxobutanoate with diethyl oxalate in the presence of sodium hydride in THF gave diethyl 4-oxo-4H-pyran-2,5- dicarboxylate, from which 4-oxo-4H-pyran-2,5-dicarboxylic and 4-oxo-1-phenyl-1,4- dihydropyridine-2,5-dicarboxylic acids and their derivatives were obtained in good yields.Программа развития УрФУ на 2013 год (п.2.1.1.1

An improved synthesis and some reactions of diethyl 4-oxo-4H-pyran-2,5- dicarboxylate

The reaction of ethyl 2-(dimethylamino)methylene-3-oxobutanoate with diethyl oxalate in the presence of sodium hydride in THF gave diethyl 4-oxo-4H-pyran-2,5-dicarboxylate, from which 4-oxo-4H-pyran-2,5-dicarboxylic and 4-oxo-1-phenyl-1,4-dihydropyridine-2,5-dicarboxylic acids and their derivatives were obtained in good yields. © 2013 Elsevier Ltd. All rights reserved

Triacetic acid lactone in the synthesis of heterocyclic compounds

This work was financially supported by the Russian Science Foundation (Grant no.17-73-20070)

A novel, two-step synthesis of 4-pyridone-3-carboxamides from 2-cyano-4-pyrones

Reactions of 2-cyano-6-(trifluoromethyl)-4-pyrone, 2-cyano-4-pyrone, and 2-cyano-6-methyl-4-pyrone with aliphatic and aromatic amines in ethanol at -20 C for 2-21 days gave 5-amino-3-oxopent-4-enamides in 28-78% yields, which were cyclized with DMF-DMA in toluene under ambient conditions to afford 4-pyridone-3-carboxamides in 31-70% yields. © 2013 Elsevier Ltd. All rights reserved

Производство новолачных олигомеров

The paper presents the improvement of production technology of novolac phenol-formaldehyde oligo-mers by introducing the new scheme of capture of exhaust gases due to waste production, which leads to a reduction of costs and increase economic efficiency. The calculation of the material balance of the pro-duction of novolac phenol-formaldehyde oligomer at 300 kg/h of technical product is performed, the technological calculation of the basic equipment and selection of auxiliary equipment is produced. The apparatus scheme of production is made and the description of the process is represented. The draft of the main reactor is made.В работе представлено усовершенствование технологии производства новолачных фенолоформальдегидных олигомеров путем введения новой схемы улавливания отходящих газов за счет отходов производства, что приводит к сокращению расходов и увеличению экономической эффективности. Выполнен расчет материального баланса производства новолачного фенолоформальдегидного олигомера на 300 кг/ч технического продукта, произведен технологический расчет основного и выбор вспомогательного оборудования. Составлена аппаратурная схема производства, а также представлено описание технологического процесса. Выполнен чертеж основного реактора

Crystal structures of two (Z)-2-(4-oxo-1,3-thiazolidin-2-ylidene) acetamides

The crystal structures of two (oxothiazolidin-2-ylidene)acetamides, namely (Z)-2-[2-(morpholin-4-yl)-2-oxoethylidene]thiazolidin-4-one, C9H12N2O3S, (I), and (Z)-N-(4-methoxyphenyl)-2-(4-oxothiazolidin-2-ylidene)acetamide, C12H12N2O3S, (II), are described and compared with a related structure. The Z conformation was observed for both the compounds. In (I), the morpholin-4-yl ring has a chair conformation and its mean plane is inclined to the thiazolidine ring mean plane by 37.12 (12)°. In (II), the benzene ring is inclined to the mean plane of the thiazolidine ring by 20.34 (14)°. In the crystal of (I), molecules are linked by N—H...O hydrogen bonds, forming C(6) chains along the b-axis direction. The edge-to-edge arrangement of the molecules results in short C—H...O and C—H...S interactions, which consolidate the chain into a ribbon-like structure. In the crystal of (II), two N—H...O hydrogen bonds result in the formation of C(8) chains along the b-axis direction and C(6) chains along the c-axis direction. The combination of these interactions leads to the formation of layers parallel to the bc plane, enclosing R44(28) rings involving four molecules

Influence of solvent and substituents on the reaction of N-alkylthioacetamides with dimethyl acetylenedicarboxylate: Synthesis of functionalized thiophenes containing an exocyclic double bond

The reaction of thioacetamides with dimethyl acetylenedicarboxylate affords 3-oxothien-2-ylidene or 4-oxothiazol-2,5-ylidene derivatives based on the structure of the thioacetamides and the solvent employed. The structural features of the 3-oxothien-2-ylidenes are discussed. © 2013 Elsevier Ltd. All rights reserved

2-(4-Oxo-1,3-thiazolidin-2-ylidene)acetamid as promising scaffold for designing new antifungal compounds

1,3-Thiazolidin-4-one derivatives with a exocyclic C=C double bond in position 2 of the hetero ring have a wide spectrum of biological activity, but their fungicidal activity has not been studied as much as it should be. This paper presents a simple and convenient approach for obtaining potential antifungal agents based on 2-(4-oxo-1,3-thiazolidin-2-ylidene)acetamides. The first examples of evaluating the fungicidal activity of 8 obtained compounds on 8 strains of phytopathogenic fungi are presented. A highly active compound 4e with EC50 of 0.85 and 2.29 µg/mL against A. solani and P. lingam, respectively, was found to be promising for further study

Bio-based Triacetic Acid Lactone in the Synthesis of Heterocycles Via the Enaminone Formation

This work was financially supported by the Russian Science Foundation (grant № 18-13-00186)