Ethanol → Ethyl 5-bromothiophene-2-carboxylate

2-Bromo-5-thiophenecarboxylic acid (500 mg) was dissolved in ethanol (5 mL), conc. sulfuric acid (50 μL) was added and the mixture was heated under reflux for 4 hrs. Conc. sulfuric acid (50 μL) was further added and the mixture was heated under reflux for 5 hrs. Then, the mixture was allowed to return to room temperature. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography using a mixed solvent of ethyl acetate and hexane as an eluent. The solvent was evaporated from the eluent to give the title compound (500 mg) as a yellow oil.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 4 hrs
3. temperaturethe mixture was heated
4. temperatureunder reflux for 5 hrs
5. customto return to room temperature
6. extractionthe mixture was extracted with ethyl acetate
7. washThe extract was washed with saturated brine
8. customdried
9. customthe solvent was evaporated under reduced pressure
10. customThe residue was purified by silica gel column chromatography
11. customThe solvent was evaporated from the eluent

ORD record

ord-0a0f627c34d84b46911a9af5e8f7f767

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07935700B2