共查询到20条相似文献,搜索用时 15 毫秒
1.
3,4- and 3,5-bis(chloromethyl)-2-isobutylfurans react with sodium diethyl phosphite by the Michaelis-Becker reaction scheme to form phosphonates whose yield significantly depends on the location of the halomethyl group in the furan ring. 3,4-Bis(chloromethyl)-2-isobutyl-5-methylfuran under analogous conditions gives a diphosphonate, while in 3,5-bis(chloromethyl)-2-isobutylfuran phosphorylation of the α-chloromethyl group competes with dehydrochlorination leading to a chloromethylated alkene, the second process being preferred. Further phosphorylation involves only one chloromethyl group of the alkene. Ethyl 5-(bromomethyl)-2-isobutylfuran-3-carboxylate reacts with sodium acetate to give a substitution product, while its isomer with the reverse location of the substituents eliminates hydrogen bromide exclusively. In the latter case, the acetate is formed only as a minor product.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 991–998.Original Russian Text Copyright © 2005 by Pevzner. 相似文献
2.
Abstract Dimethyl benzoylphosphonates (1) react with trimethyl phosphite to give anionic intermediates (2) which decompose to give carbenes (3) and trimethyl phosphate [1]. When suitable ortho-substituents are present on the benzoylphosphonate, intramolecular carbene insertion reactions can occur to give cyclic systems. With alkyl substitutents, where the length of the chain provides a choice of cyclisation pathways, insertion into an appropriate C[sbnd]H bond to give a 5-membered ring has been found to be the preferred option. We have therefore been investigating the behaviour of systems, such as (4), where insertion into a C[sbnd]H bond to give a 5-membered ring is prevented. 相似文献
3.
Reactions of lithium and magnesium o-carborane derivatives with ethyl -nitrocinnamate, ethyl -(3-indolyl)--nitroacrylate, and diethyl m-nitrobenzylidenemalonate were studied. Some specific features of these reactions were established, and preparative methods for the synthesis of previously unknown o-carborane derivatives were developed. 相似文献
4.
Alkyl 2-methyl-4-(diethoxyphosphorylmethyl)-5- tert-butylfuran-3-carboxylates are selectivelybrominated with N-bromosuccinimide at the methyl group in position 2 of the ring. The resulting bromo-methyl derivatives react with secondary amines to form tertiary amines, with sodium butylthiolate inmethanol to form the corresponding sulfide. The reaction with potassium thiocyanate in DMF at 80°C givesa mixture of thiocyanate and isothiocyanate. When treated with phenolate or alcoholate ions, the bromomethylfurans decompose. 相似文献
5.
5- tert-Butyl-4-chloromethyl-, 5- tert-butyl-4-(diethoxyphosphorylmethyl)-3-methylfuran-2-carboxylates are effectively brominated with N-bromosuccinimide by the 3-methyl group. The bis(halomethyl)derivative is phosphorylated under conditions of the Arbuzov reaction to give the corresponding chloromethylphosphonate. The obtained organophosphorus derivatives of bromomethyl- and chloromethylfuran-2-carboxylic acid react with secondary amines and sodium butanethiolate to form the corresponding substitution products. Alkyl 5- tert-butyl-4-chloromethyl-3-(diethoxyphosphorylmethyl)-furan-2-carboxylate reacts with sodium acetate in acetic acid to give a 4-acetoxymethyl derivative. It is the first example of a facile reaction with O-nucleophiles of halomethyl derivatives of phosphonomethylated furans. 相似文献
6.
Russian Journal of General Chemistry - The reactions of alkyl-3-nitroacrylates with semicarbazide as representative of polynitrogen nucleophiles proceeds at room temperature in a solution of... 相似文献
7.
Photocyclization of 2-(pentafluoroanilino)-, 2-(4-chloro-2-iodoanilino)-, 2-(2-chloro-4-iodo-anilino)-4,6-dimethylpyrimidines, as well as 2-(2-chloro-3-methylanilino)pyridine was used to prepare con-densed azinobenzimidazoles, including previously unknown 8-chloro-1,3-dimethylpyrimido[1,2- a]benzimidazole and 9-methylpyrido[1,2- a]benzimidazole. With isomeric chloroiodoanilinopyrimidines as example it was shown that the iodine atom affects photocyclization direction. Quaternization of 6,7,8,9-tetrafluoro-1,3-dimethylpyrimido[1,2- a]benzimidazole, 8-chloro-1,3-dimethylpyrimido[1,2- a]benzimidazole, and 9-methylpyrido[1,2- a]benzimidazole with alkylating agents and C-H activity of alkyl groups in the quaternary salts in reactions with orthoformic ester were studied. 相似文献
8.
Russian Journal of General Chemistry - The reactions of alkyl 3-nitroacrylates with representatives of aryl(hetaryl) carboxylic acid hydrazides and substituted phenylhydrazines were studied. It was... 相似文献
9.
Russian Journal of General Chemistry - The reactions of alkyl 3-bromo-3-nitroacrylates with aliphatic alcohols at reflux led to the formation of O-adducts—alkyl... 相似文献
10.
An unusual route has been found for the hydrolysis of 3-amino-1,1-dialkoxy-6,7-dialkyl-4-aryl-3a,4,5,7a-tetrahydro-1H-pyrrolo[3,4- c]pyridine-3a,7a-dicarbonitriles in acidic medium which leads to the formation of alkyl 5,6-dialkyl-2-amino-3-cyanopyridine-4-carboxylates. 相似文献
11.
A simple method for the preparation of industrially important alkyl aryl ethers is reported. Several phenolic compounds such as phenols, naphthols, and hydroxy coumarins were O-methylated with trimethyl phosphite or trimethyl phosphate under microwave irradiation and solvent-free condition in almost quantitative yields. Reaction of 2-naphthol with trimethyl phosphate gave mixture of 2-methoxynaphthalene and 1-methyl-2-methoxynaphthalene while the reaction with trimethyl phosphite gave mostly 2-methoxynaphthalene. This method is highly efficient for the methylating of phenolic compounds with very easy experimental procedure and environmental friendly conditions. 相似文献
12.
AbstractAn operationally simple domino approach for the ruthenium-catalyzed synthesis of ( E)-2,3′-bi(3 H-indol)-3-one O-alkyl oximes by the region- and stereoselective three-component, four-molecule reactions of indoles with sodium nitrite and alkyl bromides under mild reaction condition in dimethylformamide is described. Remarkably, multiple bonds including C?C, C=N, and C?O bonds were conveniently formed in one pot. The reaction is tolerant to air and is atom economical, in accordance with the concept of modern green chemistry. 相似文献
13.
In reaction of alkyl 2-amino-5,6-dialkyl-3-cyanopyridine-4-carboxylates with isocyanates formed unstable ureas, and with nitrous acid at 60–70°C alkyl 5,6-dialkyl-2-oxo-1,2-dihydro-4-pyidinecarboxylates were obtained. It was shown for the latter that their reactions with organic acids and amides occurred at the cyano group, and the alkaline hydrolysis involved the ester group. 相似文献
14.
Reactions of roquefortin with alkyl chloroformates provide 3-(1-(alkoxycarbonyl)imidazol-4-ylmethylene]-10b-(1,1-dimethyl-2-propenyl)-5a,10b,11,11a-tetrahydro-2 H-pyrazinol[1',2':1,5]pyrrolo[2,3-b]indole-1,4(3 H,6 H)-diones. 相似文献
16.
Russian Journal of Organic Chemistry - Condensations of chloromethyl propargyl(allyl) ethers with alkyl 3-oxobutanoates in the presence of pyridine gave substituted 1,3-dioxanes. 相似文献
17.
The indirect introduction of an azolyl group in position 5 of compound 1 by an easy two-step procedure taking place at room temperature is described. A similar procedure yields the 4-chloro derivatives of these 5-azolyl compounds. The same method is applied for the introduction of a 5-azido group and from the 5-azido compounds, 5- v-triazolyl derivatives are obtained by a known method. 相似文献
18.
3,3',5,5'-Tetra- tert-butylstilbene quinone and 1,2-bis(3,5-di- tert-butyl-4-hydroxyphenyl)-1,2-bis-(diethoxyphosphinoyl)-ethane were isolated from a mixture of products of the reaction of equivalent amounts of diethyl hydrogen phosphite and 3,5-di- tert-butyl-4-hydroxybenzaldehyde. A scheme of chemical transformations in this reaction system was offered. 相似文献
19.
Process of thermolysis of sodium borohydride dihydrate samples produced from solution and via a vapor was considered. A study of an acetonitrile solution made by the method of nuclear magnetic resonance demonstrated that the stoichiometry is observed in both cases. An X-ray diffraction analysis evidenced that the sample produced via a vapor is defective. It was found that, in both cases, the process begins after the reaction of peritectic decomposition of the starting compound occurs and a liquid phase is formed. The enthalpy of the peritectic reaction was determined to be ΔHreact = 18.6 ± 1.5 kJ mol?1 for the sample crystallized from an alkaline solution. For the sample produced via a vapor, this quantity is substantially smaller. The kinetics of a low-temperature thermolysis (40–80°C) of both samples is described by the Avrami—Erofeev equation. 相似文献
20.
Russian Journal of General Chemistry - A series of novel enamines, bis(enamines), benzisoxazoles, tetrahydroindazoles, benzophenone hydrazones were obtained via reactions of... 相似文献
|