Specific Features of Reactions of Halomethyl Derivatives of 2-Isobutylfuran with Nucleophiles

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.     

Studies of the Reactions of 2-Substituted Dimethyl Benzoylphosphonates with Trimethyl Phosphite

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.     

Some Specific Features of Conjugate Addition Reactions with Lithium and Magnesium o-Carborane Derivatives

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.     

Synthesis of Alkyl 2-Bromomethyl-4-(diethoxyphosphorylmethyl)-5-tert-butylfuran-3-carboxylates and Their Reactions with Nucleophilic Agents

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.     

Synthesis of Halomethyl Derivatives of 3- and 4-(Dialkoxyphosphorylmethyl)-5-tert-butylfuran-2-carboxylic Acid and Their Reactions with Nucleophilic Agents

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.     

Alkyl 3-Nitroacrylates in Reactions with Semicarbazide

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...     

Photosynthesis and Properties of Halomethyl Derivatives of Azinobenzimidazoles

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.     

Alkyl 3-Nitroacrylates in Reactions with Substituted Hydrazines

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...     

Alkyl 3-Bromo-3-nitroacrylates in Reactions with Aliphatic Alcohols

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...     

Synthesis of Alkyl 5,6-Dialkyl-2-amino-3-cyanopyridine-4-carboxylates

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.     

A New Protocol for O-Methylation of Phenolic Compounds with Trimethyl Phosphite or Trimethyl Phosphate Under Solvent-Free Condition and Microwave Irradiation

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.     

Three-Component,Four-Molecule,Ru-Catalyzed Cascade Reactions of Indoles and Alkyl Bromides with Sodium Nitrite

Abstract

An operationally simple domino approach for the ruthenium-catalyzed synthesis of (E)-2,3′-bi(3H-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.     

Alkyl 2-amino-5,6-dialkyl-3-cyanopyridine-4-carboxylates in reactions with electrophilic reagents

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.     

Reactions of Roquefortin with Alkyl Chloroformates

Reactions of roquefortin with alkyl chloroformates provide 3-(1-(alkoxycarbonyl)imidazol-4-ylmethylene]-10b-(1,1-dimethyl-2-propenyl)-5a,10b,11,11a-tetrahydro-2H-pyrazinol[1',2':1,5]pyrrolo[2,3-b]indole-1,4(3H,6H)-diones.     

Synthesis of Alkyl 4-Ethyn(en)yl-6-methyl-1,3-dioxane-5-carboxylates

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.     

Reactions of methyl 3-hydroxythiophene-2-carboxylate. Part 4. Synthesis of methyl 5-azolyl-3-hydroxythiophene-2-carboxylates

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.     

New Data on the Reaction of Diethyl Hydrogen Phosphite with 3,5-Di-tert-butyl-4-hydroxybenzaldehyde

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.     

Synthesis of Sodium Borohydride Dihydrate and Specific Features of Its Thermolysis

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 ΔH_react = 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.

     

Reactions of 2-Acetyl-5-hydroxy-5-methyl-3-phenylcyclohexanone and Alkyl 4-Hydroxy-4-methyl-2-oxo-6-phenylcyclohexanecarboxylates with Nucleophilic Reagents

Russian Journal of General Chemistry - A series of novel enamines, bis(enamines), benzisoxazoles, tetrahydroindazoles, benzophenone hydrazones were obtained via reactions of...