ChemInform Abstract: DECARBOXYLATION OF MONOSUBSTITUTED DERIVATIVES OF CARBONIC ACID. COMPARATIVE STUDIES OF WATER- AND ACID-CATALYZED DECARBOXYLATION OF SODIUM ALKYL CARBONATES IN WATER AND WATER-D2

1978 ◽  
Vol 9 (36) ◽  
Author(s):  
Y. POCKER ◽  
B. L. DAVISON ◽  
T. L. DEITS
Keyword(s):  
Comparative Studies ◽  
Carbonic Acid ◽  
Acid Catalyzed ◽  
Derivatives Of

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

Preliminary Note on Dietthio and Diethylsulphone derivatives of Succinic Acid

1897 ◽  
Vol 21 ◽  
pp. 156-159
Author(s):  
Crum Brown ◽  
R. Fairbairn
Keyword(s):  
Succinic Acid ◽  
Calcium Chloride ◽  
Boiling Point ◽  
Carbonic Acid ◽  
Steam Bath ◽  
Sodium Bromide ◽  
Absolute Alcohol ◽  
Preliminary Note ◽  
Aqueous Layer ◽  
Derivatives Of

Sodium mercaptide and dibromosuccinic ether, in the proportion of two molecules of the former to one of the latter, were dissolved separately in absolute alcohol, and slowly mixed. A considerable evolution of heat took place, while sodium bromide separated out. The flask was then digested for some hours on the steam-bath. The alcohol was subsequently distilled off, and the residue, on cooling, was treated with water. An oil separated out. This oil was collected by means of a separating funnel, and the aqueous layer several times extracted with ether. The oil and the ethereal extracts were added together and dried over calcium chloride. Next morning the ether was distilled off at the ordinary pressure. The remainder was distilled in vacuo. Between 50° and 60° a few drops came over, which proved to be ethyldisulphide.The remainder came over between 150° and 170°.This latter fraction was redistilled, and a portion of it used for analysis. The boiling point at 20 mm. pressure was 160°.Combustion of dietthiosuccinic ether.Weight of substance taken = ·2477 gram.Weight of carbonic acid obtained = ·4476 gram.Weight of water obtained = ·1702 gram.

Reaktionsverhalten von β-Oxo-carbonsäurederivaten der Anthracenreihe bei der Synthese von Pyrazolen / On the Reaction Behavior of ß-Oxo Carbonic Acid Derivatives of the Anthracene Series in Pyrazole Synthesis

1999 ◽  
Vol 54 (9) ◽  
pp. 1133-1137
Author(s):  
Astrid Knieß ◽  
Margit Gruner ◽  
Roland Mayer
Keyword(s):  
Carbonyl Group ◽  
Carbonic Acid ◽  
Ester Group ◽  
Reaction Behavior ◽  
Anthracene Derivatives ◽  
Sterical Hindrance ◽  
Derivatives Of

ß-Oxo-1 and 9-anthracenepropionate (6 and 7) reacts with DMF-acetale to enaminones 10 and 11. The reaction of 2-(dimethylamino)methylen-substituted ß-oxo-1 -anthracenepropionate (10) with hydrazines yields 5-(l-anthracenyl)-pyrazol-4-carboxylates (13). In contrast, the cyclocondensation of 3-(9-anthracenyl)-2-(dimethylamino)methylen-3-oxo-propionate (11) with hydrazine hydrochlorides gives 4-(9-anthracenoyl)-5-hydroxy-pyrazoles (14). This is caused by the sterical hindrance of the carbonyl group of the anthracene derivatives in position 9; thus, the cyclocondensation proceeds via reaction of the ester group of the enaminone 11.

Gas Chromatographic Analysis of Amino Acids as the jV-Heptafluorobutyryl Isobutyl Esters

1987 ◽  
Vol 70 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Samuel L MacKenzie
Keyword(s):  
Amino Acids ◽  
Capillary Column ◽  
Packed Column ◽  
Complex Mixture ◽  
Amino Acid Profile ◽  
Reaction Sequence ◽  
Maximum Resolution ◽  
Acid Catalyzed ◽  
Derivatives Of ◽  
Heptafluorobutyric Anhydride

Abstract The N-heptafluoroburyryl isobutyl derivatives of proteic amino acids are well resolved by gas chromatography and form the basis of a convenient, rapid assay. The derivatives are prepared by acid-catalyzed esterification at 120°C for 20 min in 3N HCl-isobutanol followed by acylation with heptafluorobutyric anhydride at 150°C for 10 min. The reaction sequence is performed without any transfers or extractions and thus is compatible with microscale analysis. A complete proteic amino acid profile can be completed in less than 20 min by using a packed column or less than 10 min by using a capillary column in combination with an elevated oven temperature program rate. Physiological sample matrixes, which frequently contain a complex mixture of components, and thus require maximum resolution, can be assayed in less than 1 h using a program rate of 4°C/min. A capillary column is recommended for this application. Capillary column chromatography, in combination with a nitrogenspecific detector, is useful for identifying and assaying nonproteic amino acids in physiological sample matrixes. Frequently, a prior cleanup of the sample can be avoided.

Isocarbostyrils. II. The Conversion of 2-Methyl-4-acyl-5-nitroisocarbostyrils to 2-Substituted Indole-4-carboxylic Acids

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Alkaline Hydrolysis ◽  
Mannich Reaction ◽  
Reductive Cyclization ◽  
Acid Catalyzed ◽  
Acid Anhydrides ◽  
Hydrolysis Of ◽  
Derivatives Of

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.

Acid-Catalyzed Reactions of 2,3-Epoxy Derivatives of Citral with Alcohols

2003 ◽  
Vol 39 (7) ◽  
pp. 985-991 ◽  
Author(s):  
O. I. Yarovaya ◽  
D. V. Korchagina ◽  
O. V. Salomatina ◽  
M. P. Polovinka ◽  
V. A. Barkhash
Keyword(s):  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Derivatives Of
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