Ethyl 6-methoxybenzo[b]thiophene-2-carboxylate → Ethyl 6-hydroxybenzo[b]thiophene-2-carboxylate

To a solution of ethyl 6-methoxy-1-benzothiophene-2-carboxylate (5.58 g, 23.6 mmol) in methylene chloride (50 mL) was added dropwise 1 M boron tribromide methylene chloride solution (71 mL, 70.8 mmol) at −20° C., and the mixture was stirred at room temperature for 3 hr. The reaction mixture was poured into ice, and the mixture was extracted twice with ethyl acetate. The extract was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=3:2) to give the title compound (1.76 g, yield 34%) as a white solid.

1. additionThe reaction mixture was poured into ice
2. extractionthe mixture was extracted twice with ethyl acetate
3. washThe extract was washed with saturated brine
4. dry with materialdried over anhydrous sodium sulfate
5. customThe solvent was evaporated under reduced pressure
6. customthe obtained residue was purified by silica gel column chromatography (hexane to hexane:ethyl acetate=3:2)

ORD record

ord-5a1783e8953446619ffd7244f99dfec2

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08501804B2