Synthesis of Novel Triazolyl-substituted Carboxylic Acid Esters and Their Aminolysis

Russian Journal of Organic Chemistry - Recyclization of 4-oxo-1,3-benzoxazinium perchlorates under the action of hydrazinobenzoic acids gave previously unknown 1,2,4-triazolylbenzoic acids which...     

含氯羧酸吡唑醛肟酯化合物的合成及生物活性

含氯羧酸吡唑醛肟酯化合物的合成及生物活性;羧酸吡唑醛肟酯;合成;生物活性     

A Novel Method for the Synthesis of Carboxylic Esters Catalyzed by Expandable Graphite

Esterification reaction of carboxylic acid and alcohol has been carried out in excellent yield with expandable graphite as a catalyst.     

Preparation of Functionalized Esters of Carboxylic Acids

The synthesis of simple esters (methyl, ethyl, etc.) of carboxylic acids is generally a trivial synthetic transformation due to the great variety of mehtods available (CH₂N₂, MeOH-H⁺,Me₂SO₄-Base, copper salts-alkylhalides¹, and CaO with alkylhalides²). However, what was sought in this laboratory were methods for preparation of functionalized esters. Specifically, Investigations are underway to develop methods for intra molecular transfer or intramolecular reaction of the functionalized (“R”) portion of the carboxylic acid ester (as illustrated below).     

Some Conversions of Thiazoline Carboxylic Acid Esters

We have carried out solvolysis of the previously described ethyl esters of 3-methyl(aryl)-4-methyl-2-thioxothiazoline-5-carboxylic acids, leading to the corresponding acids without breaking down the heterocycle. We synthesized a series of novel esters from the latter by treatment with dimethyl sulfate or reactive halides. Of these, only in the case of the ethyl ester of 3,4-dimethyl-2-thioxothiazoline-5-carboxylic acid did we obtain the hydrazinolysis product (the hydrazide), from which we synthesized novel hydrazones by treatment with aldehydes and ketones.     

Acyl Iodides in Organic Synthesis: V. Reactions with Carboxylic Acid Esters

Acyl iodides react with alkyl, alkenyl, and aralkyl esters derived from saturated, unsaturated, and aromatic mono- and dicarboxylic acids in the absence of a catalyst. The reaction involves cleavage of the OR bond and formation of organic iodide RI (including CH₂=CHI) and one or two symmetric carboxylic acid anhydrides. Phenyl acetate reacts with benzoyl iodide to give acetyl iodide and phenyl benzoate as a result of cleavage of the (O=)C–O bond. The reaction of diethyl fumarate with acetyl iodide is accompanied by cis– trans isomerization to afford maleic anhydride. In the reactions of acetyl iodide with diethyl oxalate and diethyl malonate, CO and CO₂ and CO₂ and polyketene are formed, respectively, in addition to ethyl iodide and acetic anhydride. Ethyl esters of strong organic acids, e.g., ethyl trihaloacetates, failed to react with acyl iodides under analogous conditions.     

Synthesis of Esters from Cage-Like Unsaturated Hydrocarbons,Carboxylic Acid Anhydrides,and Water

A convenient method for the preparation of esters was developed on the basis of reaction of cage-like polycyclic olefins with carboxylic acid anhydrides and water. Mixed anhydrides were found to give rise to the corresponding low-molecular acid esters. Among the obtained esters, acetates possess a pleasant odor, and they can be used as components of synthetic fragrant substances.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 995–998.Original Russian Text Copyright © 2005 by Mamedov, Nabieva, Rasulova.     

Mild Transformation of Telluro and Seleno Esters into Carboxylic Acid and Esters

Te-Butyl Telluroesters and Se-Butyl Selenoesters are hydrolyzed to carboxylic acids under very mild conditions by reaction with copper(II) chloride dihydrate. When the reaction is performed in ethanol or methanol, using anhydrous copper(II) chloride a transesterification occurred leading to the oxygenated esters in good yield.     

典型表面活性剂结构和组成的波谱表征——山梨醇酐脂肪酸酯和聚氧乙烯山梨醇酐脂肪酸酯的波谱

用核磁共振波谱、质谱和红外光谱表征了非离子表面活性剂中山梨醇酐脂肪酯和聚氧乙烯山梨醇酐脂肪酸酯的结构特征和它们的组成。     

Oxidative Conversion of Aldoximes into Carboxylic Acid Esters

Aromatic and aliphatic aldoximes or their O-methyl ethers can be efficiently converted into the corresponding carboxylic acid esters by treatment with an alcoholic solution of 30% hydrogen peroxide in the presence of catalytic amounts of 2-nitrobenzeneseleninic acid. Primary alcohols give excellent to good yields, secondary ones - good to moderate, but with tertiary alcohols no esterification is obserwed.     

A Convenient One Pot Synthesis of Esters of Carboxylic Acids from Alkyl or Aryl Halides

Esters of carboxylic acids were readily synthesized from alkyl or aryl halides by reacting the corresponding Grignard reagents with dimethyl, diphenyl or ethylene carbonates.     

Nucleophilic Substitution in Carboxylic Esters in Oil-In-Water Microemulsions

In hydrolysis and aminolysis of p-nitrophenyl esters of carboxylic acids in oil-in-water microemulsions on the basis of surfactants of various nature, a complex mechanism of the effect of the medium is operative, including shift of acid-base equilibria in the nucleophile. The rate constants of the processes studied are quantitatively related to the surface potential of the microdroplet. Varied hydrophobicity of the nucleophile and substrate changes the site of the reaction act and the relative contributions of aminolysis and hydrolysis.     

用裂解色谱法鉴定羧酸酯的结构

研究了用裂解气相色谱法鉴定羧酸酯结构的方法。对一些一元酸酯和二元酸酯进行了普通裂解和与碱石灰混合后的裂解,依据裂解产物可确定酯的母体酸和母体醇。直接从薄层板上取分离后的组分,不用去除吸附剂就能进行鉴定,可用于常见羧酸酯的剖析工作。     

Selective Cleavage of Carboxylic Esters in the Presence of Monosubstituted Malonates

Aliphatic carboxylic esters containing in the molecule a malonate moiety with an α-hydrogen undergo selective cleavage in the presence of potassium tertbutoxide in wet tetrahydrofuran.