ChemicalBook CAS DataBase List 2-Thiophenecarboxylic acid

2-Thiophenecarboxylic acid synthesis

12synthesis methods

Product Name:2-Thiophenecarboxylic acid
CAS Number:527-72-0
Molecular formula:C5H4O2S
Molecular Weight:128.15

Thiophene 2-Carboxylic Acid, T2CA, is prepared via oxidation of 2-acetylthiophene using hypochlorite, because oxidation of alkylthiophenes leads to general breakdown of the thiophene ring.

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527-72-0
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Yield:527-72-0 72%

Reaction Conditions:

Stage #1:2-Acetylthiophene with iodine;dimethyl sulfoxide in chlorobenzene at 110; for 3 h;
Stage #2: with tert.-butylhydroperoxide in chlorobenzene at 20 - 110; for 8 h;

Steps:

33 Example 33: Preparation of thiophene-2-carboxylic acid (formula (2-19))
Add 1 mmol of 2-acetylthiophene (formula (1-19)), 6 mmol of DMSO, 0.1 mmol of I2, 2 mL of chlorobenzene solvent to a 10 mL two-neck round bottom flask equipped with a magnetic stirrer.Then the reaction flask was placed in an oil bath preheated to 110 ° C, and the magnetic stirrer was turned on for 3 h.The reaction flask was taken out, cooled to room temperature, 2 mmol of TBHP was added, and the reaction was continued at a temperature of 110 ° C for 8 hours.The reaction solution was quenched by the addition of water, and then the pH was adjusted to about 11 with a sodium hydroxide solution having a concentration of 0.1 mol/L, and the aqueous phase was taken and washed three times with diethyl ether.Then, the pH was adjusted to about 2 with a hydrochloric acid solution having a concentration of 0.1 mol/L, and then extracted three times with diethyl ether. The three ether extracts were combined, and the ether was evaporated under reduced pressure.The column chromatography was further carried out, and the eluate containing the target compound was collected by using a mixture of ethyl acetate/petroleum ether volume ratio of 1:25 as an eluent.The solvent was distilled off to give the product thiophene-2-carboxylic acid in an isolated yield of 72%.

References:

Zhejiang University of Technology;Shen Zhenlu;Li Meichao;Xu Liang;Hu Baoxiang CN108276270, 2018, A Location in patent:Paragraph 0092; 0093

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