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1.
《Tetrahedron》1987,43(18):4185-4193
Reactions between aminopyrazole-4-carboxylic acids derivatives and orthoesters or amide acetals lead, in most cases, to the introduction of a heteroalkylidene moiety on the amino group of ethyl aminopyrazole-4-carboxylates and on the β-hydrazide nitrogen atom of aminopyrazole-4-carboxhydrazides.Several factors governing the course of these reactions are discussed. 相似文献
2.
A simple and efficient method for the synthesis of ethyl 5-alkanoyl- and 5-aroyl-4-pyrone-2-carboxylates was developed, which is based on the condensation of 1-R-2-(dimethyl-aminomethylidene)butane-1,3-diones, obtained from 1,3-diketones and dimethylformamide dimethyl acetal, with diethyl oxalate in the presence of NaH in THF. Ethyl 5-acyl-4-pyrone-2-carboxylates were used in the synthesis of 6-R- and 5-RCO-comanic acids. 相似文献
3.
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
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.
A. P. Molchanov V. S. Korotkov J. Kopf R. R. Kostikov 《Russian Journal of Organic Chemistry》2005,41(7):1036-1042
Substituted ethyl 1,2,3,4,4′,5′-hexahydrospiro[naphthalene-2,5′-pyrazole]-3′-carboxylates react with chlorine or N-bromosuccinimide to give spirocyclic substituted 3-halo-4,5-dihydro-3H-pyrazoles which lose nitrogen molecule on heating with formation of substituted spirocyclic 1-halocyclopropane-1-carboxylates. Heating of the title compounds with bromine in acetic acid results in opening of the spiro-fused six-membered ring to afford ethyl 4-aryl-5-[2-(2-carboxyphenyl)ethyl]pyrazole-3-carboxylates.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1058–1063.Original Russian Text Copyright © 2005 by Molchanov, Korotkov, Kopf, Kostikov. 相似文献
6.
Biginelli reaction of ethyl acetoacetate, thiourea and the appropriate aromatic aldehyde was used to produce ethyl 4-aryl-6-methyl-2-thioxo-1,2,3,4-tetrahydro-pyrimidine-5-carboxylates, that reacted with bromomalononitrile to give ethyl 3-amino-5-aryl-2-cyano-7-methyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylates rather than the isomeric 7H-thiazolo[3,2-a]pyrimidines. Thiazolopyrimidine derivatives reacted with carbon disulphide to yield ethyl 9-aryl-7-methyl-2,4-dithioxo-2,3,4,9-tetrahydro-1H-thiazolo[3,2-a:4,5-d']dipyrimidine-8-carboxylates, that reacted with phenacyl bromide to produce ethyl 8-methyl-10-(4-methoxyphenyl)-3-substituted-5-thioxo-2(un)subatituted-10H-thiazolo[3',2':1',2']pyrimido[4',5':4,5]thiazolo[3,2-a]pyrimidine-9-carboxylates. The aforementioned reactions were carried out using both conventional chemical methods and with the assistance of microwave irradaition. Comparison between both methods showed that the microwave assisted method is preferable because of the time reduction and yield improvements achieved. The new compounds were tested for their biological activity as antioxidants, antibacterial or antifungal agents. Some of the new compounds were found to have moderate to good antioxidant and antimicrobial activities. 相似文献
7.
Monobromination of 1,5-cyclooctadiene, followed by cyclopropanation with ethyl diazoacetate, led to the formation of endo and exo ethyl 4,5-dibromobicyclo[6.1.0]nonane-9-carboxylates 3a and 3b. Bis-dehydrobromination of 3a and 3b using 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) afforded the endo and exo ethyl bicyclo[6.1.0]nona-3,5-diene-9-carboxylates 4a and 4b. Reduction of these compounds to the corresponding alcohols 5a and 5b and subsequent oxidation with pyridinium chlorochromate (PCC) resulted in the formation of the target compounds endo and exo bicyclo[6.1.0]nona-3,5-diene-9-carboxaldehydes 6a and 6b. 相似文献
8.
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
9.
Yoichi Yamada Heinosuke Yasuda Yuichi Yoshihara Kazue Yoshizawa 《Journal of heterocyclic chemistry》1999,36(5):1317-1321
A series of ethyl 7-amino-2,4-dioxopteridine-6-carboxylates 4 and ethyl 7-amino-4-oxo-2-thioxopteridine-6-carboxylates 5 , of interest biologically, has been prepared in one step from the reaction of such vicinal-diamines as 1,3-dialkyl-5,6-diaminouracils 2 or 1,3-dialkyl-5,6-diamino-2-thiouracils 3 with diethyl (E)-2,3-dicyanobutenedioate ( 1 ). Moreover, ethyl 3-amino[1,2,4]triazino[2,3-a]-1H-benzimidazole-2-carboxylate ( 11 ) was also obtained from the reaction between 1,2-diamino-1H-benzimidazole ( 10 ) and 1 . The structural studies of 4, 5 , and 11 prepared were carried out by nmr experiments in some details. 相似文献
10.
S. G. Mikhalenok N. M. Kuz'menok A. M. Zvonok 《Chemistry of Heterocyclic Compounds》2005,41(8):977-986
It was established that, in addition to ethyl 4-aryl-3-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-5-carboxylates, the reaction
of diazoacetic ester with β-arylacryloyloxiranes also gives ethyl 4-aryl-3(5)-(3-hydroxy-2-methylalkanoyl)-1H-pyrazole-5(3)-carboxylates.
The latter are formed from the tautomeric ethyl 4-aryl-5-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-3-carboxylates as a result
of intramolecular oxidative-reductive disproportionation.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1150–1160, August, 2005. 相似文献
11.
V. V. Dotsenko I. A. Lebedeva S. G. Krivokolysko M. V. Povstyanoi V. M. Povstyanoi E. O. Kostyrko 《Chemistry of Heterocyclic Compounds》2012,48(3):462-469
Alkylation of N-methylmorpholinium 4-Ar1-3-cyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates using ethyl 4-Ar-6-bromomethyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates
(10 % KOH, DMF) gives mixtures of diastereomers of ethyl 4-Ar-6-[(4-Ar1-3-cyano-1,4,5,6-tetrahydropyridin-2-ylthio)methyl]-1-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates in overall
30-58 % yield. Under these conditions the N-methylmorpholinium 4-Ar1-5-(N-Ar2-carbamoyl)-3-cyano-6-methyl-1,4-dihydropyridine-2-thiolates undergo aromatization of the dihydropyridine ring to give ethyl
4-Ar-6-[4-Ar1-5-(N-Ar2-carbamoyl)-3-cyano-6-methylpyridin-2-ylthio)methyl]-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates (37-51 %). In the absence
of KOH, only the substituted pyridine-2(1 H)-thione is formed as a product of oxidation of the dihydropyridine ring in the
starting substrate. Some of the alkylation products obtained possess weak or moderate antibacterial activity towards the specific
strains of Escherichia coli and Bacillus subtilis but are inactive towards Candida albicans and Staphylococcus aureus. 相似文献
12.
Ethyl 1-aryl-4-acetyl-5-methyl-1H-pyrazole-3-carboxylates reacted with phenylhydrazine to give the corresponding hydrazones, ethyl 1-aryl-5-methyl-4-[1-(phenylhydrazinylidene)ethyl]-1H-pyrazole-3-carboxylates, which were converted to ethyl 1′-aryl-4-formyl-5′-methyl-1-phenyl-1H,1′H-3,4′-bipyrazole-3′-carboxylates by treatment with the Vilsmeier–Haack reagent. No indole derivatives were formed from the same hydrazones under the Fischer reaction conditions, but cyclization to 2-aryl-3,4-dimethyl-6-phenyl-2,6-dihydro-7H-pyrazolo[3,4-d]pyridazin-7-ones was observed. 相似文献
13.
Ethyl 4,5-dioxo-2-phenyl-4,5-dihydro-1H-pyrrole-3-carboxylates reacted with malononitrile and five-membered cyclic enols, indan-1,3-dione and cyclopentane-1,3-dione to give 1-substituted ethyl 2-amino-3- cyano-2′,5-dioxo-5′-phenyl-1′,2′-dihydro-5H-spiro[indeno[1,2-b]pyran-4,3′-pyrrole]-4′-carboxylates and ethyl 2-amino-3-cyano-2′,5-dioxo-5′-phenyl-1′,2′,6,7-tetrahydro-5H-spiro[cyclopenta[b]pyran-4,3′-pyrrole]-4′-carboxylates, respectively. 相似文献
14.
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
15.
Chaban T. I. Matiichuk Y. E. Matiychuk V. S. 《Russian Journal of General Chemistry》2020,90(7):1357-1361
Russian Journal of General Chemistry - A series of ethyl 4-[(Z)-(4-oxo-2-thioxo-1,3-thiazolidin-5-ylidene)methyl]-1-aryl-1H-pyrazole-3-carboxylates was obtained as a result of the reaction of ethyl... 相似文献
16.
1-Alkyl-5-phenyl-4(1H)pyrimidinones are readily synthesized by condensing β-(dimethylamino)-N-[(dimethylamino)methylene] atropamides with methyl or ethyl amine. The latter compounds are prepared from phenylacetamides and dimethylformamide dimethyl acetal. 相似文献
17.
Kochikyan T. V. Samvelyan M. A. Arutyunyan V. S. Avetisyan A. A. 《Russian Journal of Organic Chemistry》2003,39(9):1329-1333
Michael reaction of ethyl 5-alkoxymethyl-2-oxotetrahydrofuran-3-carboxylates with 3-methyl-3-buten-2-one gave ethyl 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)-2-oxotetrahydrofuran-3-carboxylates. Alkaline hydrolysis of the latter, followed by decarboxylation afforded 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)tetrahydrofuran-2-ones. The bromination of ethyl 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)-2-oxotetrahydrofuran-3-carboxylates provides a convenient method for the preparation of 3-acetyl-8-alkoxymethyl-3-methyl- and 8-alkoxymethyl-3-bromoacetyl-3-methyl-2,7-dioxaspiro[4.4]nonane-1,6-diones in high yields. 相似文献
18.
Reaction of ethyl or methyl 3-oxoalkanoates with N,N-dimethylformamide dimethyl acetal gave, generally in excellent yields, a series of ethyl or methyl 2-dimethylaminomethylene-3-oxoalkanoates II which reacted with phenylhydrazine to afford the esters of 5-substituted 1-phenyl-1H-pyrazole-4-carboxylic acids III in high yields. Esters III were hydrolyzed to the relative 5-substituted 1-phenyl-1H-pyrazole-4-carboxylic acids which were converted by heating to 5-substituted 1-phenyl-1H-pyrazoles in excellent yields. Reaction of II with methylhydrazine afforded in general a mixture of 3- and 5-substituted ethyl 1-methyl-1H-pyrazole-4-carboxylates with the exception of IIg , which gave in high yield methyl 5-benzyl-1-methyl-1H-pyrazole-4-carboxylate, which was hydrolyzed to the relative pyrazolecarboxylic acid. This afforded by heating 5-benzyl-1-methyl-1H-pyrazole in quantitative yield. 相似文献
19.
Diethyl [2-(3- or 4-pyridinyl)-4-pyrimidinyl]aminomethylenemalonates 5 prepared by the reaction between 2-(3- or 4-pyridinyl)-4-pyrimidinamines 3 and diethyl ethoxymethylenemalonate ( 4 ) were thermally cyclized to afford ethyl 5,8-dihydro-5-oxo-2-(3- or 4-pyridinyl)pyrido[2,3-d]pyrimidine-6-carboxylates 6 . The later were alkylated with ethyl iodide and then saponified to give 5,8-dihydro-8-ethyl-5-oxo-2-(3- or 4-pyridinyl)pyrido-[2,3-d]pyrimidine-6-carboxylic acids 2 . Thermal cyclization of diethyl (2-hydroxy-4-pyrimidinyl)amino-methylenemalonate ( 8 ) gave ethyl 1,6-dihydro-4,6-dioxo-4H-pyrimido[1,6-a]pyrimidine-3-carboxylate ( 10 ) instead of ethyl 5,8-dihydro-2-hydroxy-5-oxopyrido[2,3-d]pyrimidine-6-carboxylate ( 9 ) as previously claimed. 相似文献
20.
Bernard Chantegrel Christian Deshayes Bernard Pujol Zhong Jia Wei 《Journal of heterocyclic chemistry》1990,27(4):927-934
The title compounds were prepared from ethyl 5-acyl- or 5-(1-hydroxyethenyl)isoxazole-4-carboxylates which in turn were prepared from ethyl 3-methylamino-2-butenoate or 3(2H)-furanones. 相似文献