Reactions of Vanillin and Vanillal Esters with 6-Quinolylamine and Phenidone

Previously unknown 2-methoxy(or ethoxy)-4-(11-oxo-9-phenyl-7,8,9,10,11,12-hexahydrobenzo[b][4,7]phenanthrolin-12-yl)phenyl esters of carboxylic acids were prepared by ternary condensation of vanillin or vanillal alkanoates with 6-quinolylamine and Phenidone. According to the ¹H NMR spectra, the target products are formed as mixtures of diastereomers.     

Esters of Vanillin and Vanillal Oximes

Vanillin and vanillal oximes 2a and 2b were used to prepare the corresponding esters 3a-k, 4a-k, and 5a-c by reaction with acyl chlorides in the presence of pyridine.     

New Reactions with Cyanic Esters

The reactions of cyanic esters with acylating agents and the reactions of the resulting N-acyliminocarbonic ester halides are surveyed, and syntheses of heterocycles with cyanic esters and their reaction products are then reported.     

Halogen-containing Aromatic Azomethines Derived from Vanillin and Vanillal Esters

Vanillin and vanillal esters were reacted with 4-bromoaniline and 1-bromo-2-naphthylamine in methanol to obtain the corresponding halogen-containing azomethines.     

Reactions of Polyfluorinated 2-Arylhydrazono-3-oxocarboxylic Acid Esters with o-Phenylenediamine

Polyfluorinated 2-arylhydrazono-3-oxocarboxylic acid esters react with o-phenylenediamine in neutral medium to give mainly the corresponding o-aminoanilides which can be converted into 1,5-benzodi-azepin-2-ones. In the reactions with ethyl 2-arylhydrazono-3-oxobutanoate and its 4,4-di- and 4,4,4-trifluoro derivatives, ethyl 2-(2-benzimidazolyl)-2-[(4-methylphenyl)hydrazono]ethanoate is also formed.     

Reactions of S-Silyl Esters of Tetracoordinated Phosphorus Thioacids with Acetals and Ortho Esters

The reactions of S-trimethylsilyl esters of dithiophosphoric, diamidodithiophosphoric, aryldithiophosphonic, aryltrithiophosphonic, and arylamidodithiophosphonic acids with diethyl acetal of benzaldehyde and ortho formiate and acetate were studied. On the basis of these studies, new derivatives of tetracoordinated phosphorus thioacids were obtained.     

SN2 Reactions with Carboxylic Esters. Selective cleavage of methyl esters

Sodium cyanide in hexamethylphosphoric triamide selectively cleaves methyl esters in the presence of ethyl esters with yields of ca. 80%. The mechanism of the reaction has been investigated. It consists of nucleophilic displacement by cyanide of the carboxylate ion from the alcohol carbon atom (B_Al2 mechanism).     

Synthesis and Reactions of Cyanic Esters

In 1963, it was found that sterically unhindered esters of cyanic acid, which had previously been considered unobtainable, could be easily prepared from phenols and cyanogen halides. Another synthesis, involving the thermolysis of thiatriazole derivatives, was discovered in 1964. The aryl cyanates in particular have since been found to have many uses as starting materials for the preparation of numerous new classes of compounds [e.g. derivatives of esters of imidocarbonic acid (esters, amides, imides, hydrazides, hydroxylamides, sulfamides, sulfhydrazides, semicarbazides); esters of imidocarboxylic acids; s-triazines, pyrimidines, tetrazoles, triazoles, triazolones, oxadiazoles, thiadiazoles, benzoxazinones, etc.], mainly by addition of nucleophilic or 1,3-dipolar reactants, or as aids e.g. in the elimination of H₂O or H₂S or in the transfer of CN groups.     

Ruthenium-Catalyzed Coupling Reactions of CO2 with C2H4 and Hydrosilanes towards Silyl Esters

A series of in situ-prepared catalytic systems incorporating Ru^II precursors and bidentate phosphine ligands has been probed in the reductive carboxylation of ethylene in the presence of triethylsilane as reductant. The catalytic production of propionate and acrylate silyl esters was evidenced by high-throughput screening (HTS) and implemented in batch reactor techniques. The most promising catalyst systems identified were made of Ru(H)(Cl)(CO)(PPh₃)₃ and 1,4-bis(dicyclohexylphosphino)butane (DCPB) or 1,1’-ferrocene-diyl-bis(cyclohexylphosphine) (DCPF). A marked influence of water on the acrylate/propionate selectivity was noted. Turnover numbers [mol mol(Ru)⁻¹] up to 16 for acrylate and up to 68 for propionate were reached under relatively mild conditions (20 bar, 100 °C, 0.5 mol % Ru, 40 mol % H₂O vs. HSiEt₃). Possible mechanisms are discussed.     

New Reactions of Ortho Esters

Russian Journal of Organic Chemistry - A new reaction of triethyl orthoformate with ethyl butyrate has been revealed. It afforded diethoxymethyl butanoate and its hydrated form,...     

Aldolic Condensations on Inorganic Solid Support: Application to the Synthesis of O-Ethyl Esters of 3-Phenyl-2-propenethioic Acids

Aldolic condensations with 0-ethyl thioesters are performed on basic alumina to give 2,3-unsaturated thioates. The stereochemistry of the reaction is discussed and compared with Knoevenagel's, Pinner's and Wittig-Horner's reactions.     

Reactions of Carboxymethyl Polysaccharides and Their Ethyl Esters with Amines

The reaction of carboxymethyl polysaccharides and their ethyl esters with amines was studied with the aim to determine how the structure of the polymeric acylating agent affects the composition of the reaction products.     

Esters Derived from Vanillin and Vanillal and Aromatic and Functionalized Aliphatic Carboxylic Acids

Reactions of vanillin and vanillal with aromatic and functionally substituted aliphatic carboxylic acid chlorides in the presence of pyridine afforded the corresponding previously unknown esters.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1015–1019.Original Russian Text Copyright © 2005 by Dikusar, Kozlov.     

Vanillin Esters of Aliphatic Acids in the Synthesis of 4,7-Phenanthroline Derivatives

Condensation of vanillin esters of aliphatic acids with 6-aminoquinoline and cyclic c-diketones (1,3-cyclohexanedione and dimedone) afforded new 2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[b][4,7]phenanthrolin-12-yl)phenyl esters of carboxylic acids.     

Cyclopentanone and cyclobutanone

Crystals of cyclopentanone, C₅H₈O, and cyclobutanone, C₄H₆O, have been grown in situ on a diffractometer. The two compounds are isostructural and contain two crystallographically independent molecules. Molecules sitting across twofold axes form antiparallel dipole–dipole dimers, while other molecules in general positions are linked together into ribbons by pairs of C—H...O interactions.     

β-烯胺酯为关键中间体的串联反应研究进展

串联反应具有原料简单易得、中间产物无需分离提纯、操作简单、节省溶剂和降低消耗等很多独特优点,已成为当前有机合成研究的热点课题.缺电子炔烃与芳香胺在温和条件下快速反应生成的β-烯胺酯,具有丰富的化学反应性质,可以作为多组分串联反应的关键中间体,和其它组分进行串联反应,构建结构复杂的碳链、碳环、杂环化合物和螺环化合物.综述了近年来此类直接生成的β-烯胺酯参与的多组分串联反应的最新研究进展.