Ethyl Acetate → Methyl 3-(2-phenoxyethoxy)thiophene-2-carboxylate

Temperature

80 °C

To a solution of methyl 3-hydroxythiophene-2-carboxylate (0.992 g, 6.27 mmol) in N,N-dimethylformamide (12 ml) were added β-bromophenetole (1.268 g, 6.31 mmol) and potassium carbonate (1.059 g, 7.66 mmol), and the mixture was stirred at 80° C. for 4.5 hr. Ethyl acetate was added to the reaction mixture, the mixture was washed with water, and the organic layer was dried over sodium sulfate. The solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate) to give methyl 3-(2-phenoxyethoxy)thiophene-2-carboxylate (1.624 g, 5.83 mmol, yield 93%). This was dissolved in methanol (12 ml), 1N-aqueous sodium hydroxide solution (12 ml) was added at room temperature, and the mixture was stirred at 60° C. for 2 hr. The reaction mixture was concentrated under reduced pressure and neutralized with 1N-aqueous hydrochloric acid solution, and the mixture was extracted with ethyl acetate. The extract was dried over sodium sulfate, and the solvent was evaporated under reduced pressure to give a carboxylic acid compound 3-(2-phenoxyethoxy)thiophene-2-carboxylic acid (1.491 g, 5.64 mmol, yield 97%).

1. washthe mixture was washed with water
2. dry with materialthe organic layer was dried over sodium sulfate
3. customThe solvent was evaporated under reduced pressure
4. customthe obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate)

ORD record

ord-1732708a96274ed78306e43d53b3cd55

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08022072B2