Thiophenecarboxylic Acid Research Articles

Functional derivatives of thiophene

We have found that 4-oxothieno[2,3-d]oxazines (lla-h) can be obtained by the action of thionyl chloride on 2-aroylaminothiophene-3-carboxylic acids (la-h) in the presence of dimethylformamide (DMF), i.e., under the conditions of the synthesis of arenecarboxylic acid chlorides. The reaction evidently proceeds through a step involving the formation of thiophenecarboxylic acid chlorides. We obtained thiophenecarboxylic acids la, c, h for the first time by the method described in [2].

13C-NMR spectra of substituted thiophenecarboxylic acids

13C-NMR spectra of substituted thiophenecarboxylic acids

Studies in the thiophene series. V. Anodic oxidation of methyl esters of thiophenecarboxylic acids

Studies in the thiophene series. V. Anodic oxidation of methyl esters of thiophenecarboxylic acids

Linear free energy relationships in the furan and thiophene ring systems

The authors have correlated, by multiple linear regression analysis, sets of data taken from the literature with the Hammett equation for the dissociation constants of furoic and thiophene carboxylic acid derivatives.

A new method for the synthesis of esters of ?-thiophenecarboxylic acids

A method for the synthesis of esters of β-thiophenecarboxylic acids and diethyl 3-methyl-2,4-thiophenedicarboxylate by the deamination of derivatives of 2-amino-3-ethoxycarbonylthiophene has been proposed. Ethyl tetrahydrothionaphthene-3-carboxylate has been converted by dehydrogenation on heating with sulfur into ethyl thionaphthene-3-carboxylic acid. The corresponding acids have been obtained by the hydrolysis of the esters. A number of dialkylaminoalkyl esters has been obtained from β-thiophenecarboxylic acids and 3-methyl-2, 4-thiophenedicarboxylic acid via the acid chlorides.

The bromodecarboxylation of thiophenecarboxylic acids

AbstractBromodecarboxylation of the disodium salt of 3,4‐dimethylthiophene‐2,5‐dicarboxylate with bromine in water gave 2,5‐dibromo‐3,4‐dimethylthiophene. This bromodecarboxylation reaction, first mentioned by Melles and Backer (1953), has interesting synthetic aspects and a number of other examples are given.

Structure of the acetylation and formylation products of 2-tert-butyl-5-methylthiophene and 2,5-di-tert-butylthiophene

1. It was shown that, in the formylation, acetylation, and bromination of 2-tert-butyl-5-methylthiophene, the new substituent enters the 4-position (the β-position next to the methyl). 2. It was shown that, in the acetylation of 2,5-di-tert-butylthiophene in presence of stannic chloride, no migration of the tert-butyl group occurs. 3. It was shown that it is possible to prepare thiophenecarboxylic acids containing α-alkyl radicals (methyl, tert-butyl) by the simultaneous action of iodine and pyridine on the corresponding ketone and subsequent splitting of the resulting pyridinium salt with alkali. 4. The following were prepared for the first time: 5-tert-butyl-2-methyl-3-thiophenecarboxylic acid, 2,5-di-tert-butyl-3-thiophenecarboxylic acid, and 3-bromo-5-tert-butyl-2-methylthiophene.

Polarographic Reduction of Carbonyl Derivatives of Five Membered Heterocyclic Compounds. I. Nature of the Reduction and Effects of Substituents on the half-wave Potentials of Esters of Furan and Thiophene Carboxylic Acid

Polarographic Reduction of Carbonyl Derivatives of Five Membered Heterocyclic Compounds. I. Nature of the Reduction and Effects of Substituents on the half-wave Potentials of Esters of Furan and Thiophene Carboxylic Acid

Acylation Studies in the Thiophene and Furan Series. V. Thiophene Carboxylic Acids and Semicarbazones Derived from Acetylthiophenes

Acylation Studies in the Thiophene and Furan Series. V. Thiophene Carboxylic Acids and Semicarbazones Derived from Acetylthiophenes