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1.
In the present study, the density functional theory (DFT) and Gibbs free energy calculations were performed to investigate
the stability and tautomerism of C4-substituted-3,4-dihydropyrimidin-2(1H)-ones. Three different forms are possible for the ethyl 3,4-dihydropyrimidinones (ethyl 4-aryl-6-methyl-3,4-dihydropyrimidin-2(1H)-one-5-carboxylates, ethyl 4-aryl-2-hydroxy-6-methyl-1,4-dihydropyrimidine-5-carboxylates and ethyl 4-aryl-2-hydroxy-6-methyl-3,4-dihydropyrimidine-5-carboxylates)
forms that the most stable form is ethyl 4-aryl-6-methyl-3,4-dihydropyrimidin-2 (1H)-one-5-carboxylates (keto-form). The obtained data showed that the substitution on the C4-substitut position can be effective
on the equilibrium constant (K
eq). 相似文献
2.
Michael Beyer Ramin Ghaffari-Tabrizi Michael Jung Paul Margaretha 《Helvetica chimica acta》1984,67(6):1535-1539
On acetone-sensitized irradiation the title compounds 3a–c are converted to 2-allyl-3-hydroxy-1H-pyrrole-2-carboxylates 4 in reasonable yields. 相似文献
3.
A novel simple synthesis of 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 from N-acylglycines 1 , which are transformed with DMF in the presence of phosphorus oxychloride into 2-substituted-4-dimethyl-aminomethyleneoxazol-5(4H)-ones 2 , followed by opening into 2-aroylamino-3-dimethylamino-propenoates 3 , and nitrosation to give the oximes 4 as intermediates, which cyclize spontaneously into 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 . The compounds 2 can be transformed into 5 without isolation of 3 and 4 . 相似文献
4.
V. S. Matiichuk M. A. Potopnyk N. D. Obushak 《Russian Journal of Organic Chemistry》2010,46(10):1550-1557
Bromination of ethyl 1-aryl-4-acetyl-5-methyl-1H-pyrazole-3-carboxylates gave ethyl 1-aryl-4-(bromoacetyl)-5-methyl-1H-pyrazol-3-carboxylates which were used to alkylate benzenethiol and heterocyclic thiones at the sulfur atom. Reactions of
the resulting S-alkylation products with hydrazine or methylhydrazine involved closure of pyridazine ring to afford 2-aryl-3-methyl-4-[phenyl(or
hetaryl)sulfanylmethyl]-6,7-dihydro-2H-pyrazolo[3,4-d]pyridazin-7-ones. 相似文献
5.
Yoshinori Tominaga Atsuyuki Ushirogochi Yoshiro Matsuda 《Journal of heterocyclic chemistry》1987,24(6):1557-1567
Reaction of aryl and styryl methyl ketones 1a-m with dimethyl bis(methylthio)methylenemalonate ( 2 ) in the presence of potassium hydroxide in dimethyl sulfoxide gave the corresponding methyl 6-aryl- and 6-styryl-4-methylthio-2-oxo-2H-pyran-3-carboxylates 3a-m . 6-Aryl derivatives 3a-d,g were treated with sodium methoxide in methanol to give the corresponding 6-aryl-4-methoxy-2H-pyran-2-ones 8a-d and 9. Phenylcoumalin ( 7a ) and paracotoin ( 7b ) were synthesized by the desulfurization of 6-aryl-4-methylthio-2H-pyran-2-ones 4a,b. Similarly, anibine ( 8e ) was also synthesized from 3g . Treatment of 3 with hydrogen peroxide or 3-chloroperoxybenzoic acid gave the corresponding 4-methylsulfiny-2H-pyran-2-ones 10a-f in good yields. Displacement reactions of 10a-f with nucleophilic reagents are also described. 相似文献
6.
Long Huang Chenghao Luo Panpan Xu Bing Liu Duntie Zhang Jing Zhang Denghong Pang Yuefa Gong 《Journal of heterocyclic chemistry》2021,58(9):1755-1765
A facile synthesis of methyl 1,5-diaryl-1H-pyrrole-2-carboxylates was reported in this article. Acid-catalyzed reaction of methyl 2-aroyl-1-phenoxycyclopropanecarboxylates with aromatic amines underwent smoothly to give methyl 1,5-diaryl-1H-pyrrole-2-carboxylates in high to excellent yields under mild conditions. 相似文献
7.
Zhchepin V. V. Kalyuzhnyi M. M. Zhchepin R. V. Vakhrin M. I. 《Russian Journal of Organic Chemistry》2003,39(6):843-845
Zinc enolates formed from 1-aryl-2,2-dibromobutan-1-ones and zinc react with alkyl 6-bromo-2-oxo-2-H-chromen-3-carboxylates affording alkyl 1-aroyl-6-bromo-2-oxo-1-ethyl-1,7b-dihydrocyclopropa[c]-chromen-1a(2H)-carboxylates as a single isomer. 相似文献
8.
Starting from ethyl chlorosulfonylpyrazole-4-carboxylates we have carried out the synthesis of ketones 3 and 4 which are the first two structures of the novel 1H- and 2H-pyrazolo[3,4-c][2,1]benzothiazepine ring systems. 相似文献
9.
The triethylamine-catalyzed reaction of 4-substituted ethyl 2-acyl-3-amino-6-methylthieno[2,3-b]pyridine-4-carboxylates IIIa-h with 2,2,6-trimethyl-4H-1,3-dioxin-4-one IV gave 4-substituted ethyl 3-acetyl-2-hydroxy-7-methylthieno[2,3-b:4,5-b′]dipyridine-9-carboxylates Va-h. Some of the thienodipyridines ( V ) reacted with excess IV to give 5-substituted ethyl 3-acetyl-4,8-dimethyl-2-oxo-2H-pyrano[2,3-b]-pyrido[3′,2′:4,5]thieno[2,3-e]pyridine-10-carboxylates VI . 相似文献
10.
Wolfgang Stadlbauer Susanne Prattes Werner Fiala 《Journal of heterocyclic chemistry》1998,35(3):627-636
4-Azido-2-oxoquinoline-3-carboxylates and 4-azidocoumarin-3-carboxylates 6 , which were obtained from the corresponding 4-hydroxy derivatives 1 via 4-tosylates 2 or 4-chloro compounds 4 , cyclized upon thermolysis to 3-alkoxyisoxazolo[4,3-c]quinolin-4(5H)-ones or the corresponding coumarins 8 , whereas at slightly higher temperatures a 3-O, 4-O-rearrangement took place to give the 4-alkoxy-isoxazolo[4,3-c]-quinolin-3-ones and the corresponding coumarins 9. The necessary reaction conditions could be obtained easily with the help of differential scanning calorimetry. 相似文献
11.
4H-Chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k have been conveniently prepared by the reaction of 3-formylchromones 1a–k and ethyl 4,4,4-trifluoro-3-oxobutanoate 2a with good yields. Thus obtained 4H-chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k were reacted with amines 4a–e to provide series of 5-(2-hydroxybenzoyl)-2-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylates 5a–o. The reaction proceeded via Michael addition (C-N bond formation) and followed by cleavage of chromone and pyran rings (C-O bond cleavage) in one pot. 相似文献
12.
Ramin Ghaffari-Tabrizi Paul Margaretha Helmut W. Schmalle 《Helvetica chimica acta》1984,67(7):1957-1962
Irradiation (λ > 280 nm) of 3-hydroxy-1H-pyrrole-2-carboxylates 1 in CH3CN gives the [2.2′-bi(3-oxo-2,3-dihydro-1H-pyrrole)]-2-,2′-dicarboxylates 2 in reasonable to good yields. The corresponding N-methylpyrroles 3 only undergo slow photodecomposition under similar conditions. Several 2-methyl-3-oxo-2,3-dihydro-1H-pyrrole-2-carboxylates 4 and 5 were synthesized to compare their spectral data with those of the dehydrodimers 2 . A X-ray structure analysis was performed for diethyl [2,2′-bi(4,5-dimethyl-3-oxo-2,3-dihydro-1 H-pyrrole)]-2,2′-dicarboxylate ( 2b ). The originally proposed [3,3′-bi(3H-pyroole)] structure for compounds 2a - e proves incorrect. 相似文献
13.
Elizabeta Suhadolc Uro Urleb Ura
bontar Danijel Kikelj 《Journal of heterocyclic chemistry》1993,30(3):597-602
A convenient one pot synthesis of ethyl 3,4-dihydro-2-methyl-3-oxo-2H-1,4-benzoxazine-2-carboxylates and 3,4-dihydro-2-methyl-3-oxo-2H-pyrido[3,2-b]-1,4-oxazine-2-carboxylates and their conversion into the respective carboxylic acids are described. 相似文献
14.
The reaction of substituted ethyl 5-aminopyrazole-4-carboxylates with two equivalents of methanesul-fonyl chloride gave the substituted ethyl 5-[bis(methylsufonyl)amino]-1H.-pyrazole-4-carboxylates II . Removal of one of the methanesulfonyl groups, followed by alkylation of the ethyl 5-[(methylsulfonyl)amino]-1H-pyrazole-4-carboxylates III with methyl iodide produced the substituted ethyl 5-[methyl(methylsulfonyl)amino]-1H-pyrazole-4-carboxylates IV . Treatment of IV with sodium hydride gave the 7-substituted 1,7-dihydro-1-methylpyrazolo[3,4-c][1,2]thiazin-4(3H)-one 2,2-dioxides V . 相似文献
15.
Ricardo Bossio Stefano Marcaccini Roberto Pepino Paola Paoli Cecilia Polo 《Journal of heterocyclic chemistry》1993,30(2):575-577
The reaction between (Z)-methyl 3-dimethylamino-2-isocyanoacrylate ( 1a ) and acyl chlorides 2a,b did not afford methyl 2-acyl-1-methyl-1H-imidazole-4-carboxylates 3a,b , as previously reported, but 2-acyl-4-dimeth-ylaminomethyleneoxazol-5(4H)-ones 4a,b. 相似文献
16.
The reactions of aroylacetonitriles with the nickel chelate of ethyl acetoacetate afforded new block heterocyclic reagents, viz., 3-acetyl-4-amino-6-arylpyran-2-ones. The reactions of the latter with diethyl oxalate gave rise to ethyl 7-aryl-4,5(1H,5H)-dioxopyrano[4,3-b]pyridine-2-carboxylates. 相似文献
17.
A method for the synthesis of 5,7,8,9-tetrahydro-4H,6H-chromeno[2,3-d][1,3]oxazin-4-ones was developed. The method involves acid-catalyzed acylation of substituted ethyl 2-amino-4-aryl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylates with acetic anhydride. 相似文献
18.
E. S. Denislamova N. V. Bubnov A. N. Maslivets 《Russian Journal of Organic Chemistry》2011,47(6):933-936
Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione to give methyl 11-aryl-12-benzoyl-9-hydroxy-4,6-dimethyl-3,5,10-trioxo-4,6,8,11-tetraazatricyclo[7.2.1.02,7]dodec-2(7)-ene-1-carboxylates which underwent thermal recyclization to 1-aryl-3-benzoyl-4-hydroxy-1′,3′-dimethylspiro[pyrrole-2,5′-pyrrolo[2,3-d]pyrimidine]-2′,4′,5,6′(1H,1′H,3′H,7′H)-tetraones. 相似文献
19.
M. I. Medvedeva N. Z. Tugusheva L. M. Alekseeva V. V. Chernyshev G. V. Avramenko V. G. Granik 《Russian Chemical Bulletin》2010,59(10):1946-1958
Methyl 3-amino-4-arylaminothieno[2,3-b]pyridine-2-carboxylates containing various substituents in the benzene ring were synthesized by the Thorpe-Ziegler reaction
of 4-arylamino-2-chloropyridine-3-carbonitriles with methyl thioglycolates. The influence of the substituent in the benzene
ring, acetal structure, the solvent and the process temperature on the reactions of obtained compounds with amide acetals
was studied. It was established that reactions with dimethylacetamide dimethylacetal in toluene smoothly results in amidine
derivatives, viz., methyl 4-arylamino-3-[1-(dimethylamino)ethylidene]aminothieno[2,3-b]pyridine-2-carboxylates, regardless of the substituent in the benzene ring. Analogous reaction of p-fluoroderivative with dimethylacetamide dimethylacetal in refluxing anhydrous ethanol leads to intramolecular cyclocondensation
to produce substituted pyridothienopyrimidines, viz., 5H-1-thia-3,5,8-triazaacenaphthenes, in good yields. Amidine derivatives were the major products in the case of the coupling
of aminothienopyridines with dimethylformamide dimethylacetal under the same conditions. A new approach to the synthesis of
substituted pyridothienopyrimidines, viz., 3H-1-thia-3,5,8-triazaacenaphthylenes, based on the prolonged heating of methyl 4-arylamino-3-[1-(dimethylamino)ethylidene]aminothieno[2,3-b]pyridine-2-carboxylates in the excess of acetic anhydride was elaborated. Putative mechanisms of the processes concerned
are given. 相似文献
20.
E. S. Denislamova N. V. Bubnov Z. G. Aliev A. N. Maslivets 《Russian Journal of Organic Chemistry》2011,47(9):1362-1365
Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 3-methyl-4-phenyl-1H-pyrazol-5-amine to give methyl 7-arylcarbamoyl-6-aroyl-2-methyl-3-phenylpyrazolo[1,5-a]-pyrimidine-5-carboxylates. The molecular and crystalline structures of methyl 6-benzoyl-7-(4-chlorophenylcarbamoyl)-2-methyl-3-phenylpyrazolo[1,5-a]pyrimidine-5-carboxylate were studied by X-ray analysis. 相似文献