Thiophene-3-carboxylic acid → 5-Bromothiophene-3-carboxylic acid

Thiophene-3-formic acid (12.5 g), AcOH (83 ml) are added to a reaction flask (500 ml), stirred at room temperature and dissolved to obtain a colorless transparent liquid. A solution of Br2 (5.4 ml) in AcOH (100 ml) is placed in a constant pressure funnel and dropped to the reaction flask at room temperature and kept at a temperature below 25° C. After addition, the reaction is carried out at room temperature overnight. The reaction mixture is poured into ice-water next day, stirred for about 30 minutes, filtered to form a white powder solid. The white powder solid is crystallized with hot water, filtered and dried to obtain a white crystal of 5-bromo-thiophene-3-formic acid (10 g), content of 92% measured by HPLC.

1. dissolutiondissolved
2. customto obtain a colorless transparent liquid
3. additiondropped to the reaction flask at room temperature
4. customkept at a temperature below 25° C
5. additionAfter addition
6. stirringstirred for about 30 minutes
7. filtrationfiltered
8. customto form a white powder solid
9. customThe white powder solid is crystallized with hot water
10. filtrationfiltered
11. customdried

ORD record

ord-6913950de20c465080d5d4cc762d7d85

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08962626B2