Tetrabutylammonium Fluoride → 2-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-indole-5-carboxylic acid methyl ester

A solution of crude 4-acetylamino-3-[4-(tetrahydro-pyran-2-yloxy)-but-1-ynyl]-benzoic acid methyl ester (33.4 g, approximately 65 mmol) in anhydrous THF (300 mL) was mixed with a 1.0 M solution of tetrabutylammonium fluoride in THF (110 mL, 110 mmol); the reaction mixture was stirred at 90° C. for 4 hours under nitrogen, and then cooled to room temperature. Solvent was evaporated and the residue was taken in ethyl acetate (300 mL). The organic phase was washed with water (300 mL), brine (200 mL), and dried over anhydrous Na2SO4. The solvent was evaporated and the crude compound was purified by column chromatography on silica gel, eluting with hexanes and ethyl acetate (3:1), to give 2-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-indole-5-carboxylic acid methyl ester. Yield: 14.9 g (76%).

1. temperaturecooled to room temperature
2. customSolvent was evaporated
3. washThe organic phase was washed with water (300 mL), brine (200 mL)
4. dry with materialdried over anhydrous Na2SO4
5. customThe solvent was evaporated
6. customthe crude compound was purified by column chromatography on silica gel
7. washeluting with hexanes and ethyl acetate (3:1)

ORD record

ord-a5c0e24331da468f8db43a5322dd3eaa

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09238640B2