Ethyl Acetate → 1-[3-(Cyclopentyloxy)-4-methoxyphenyl]butane-1,3-dione

Participants

Reaction Steps

To a stirred suspension of 60% sodium hydride (200 mg, 5 mmol) and ethyl acetate (0.49 ml, 5 mmol) in tetrahydrofuran (25 ml) were sequentially added a solution of 1-[3-(cyclopentyloxy)-4-methoxyphenyl]ethanone (European Patent Application EP470805) (590 mg, 2.5 mmol) in tetrahydrofuran (5 ml), two drops of ethanol and a solution of dibenzo-18-crown (15 mg, 0.04 mmol) in tetrahydrofuran (5 ml). The reaction mixture was refluxed for 5 h, allowed to cool to room temperature and finally quenched with aqueous 10% sulphuric acid solution (5 ml). The resulting mixture was diluted with diethyl ether, washed with saturated ammonium chloride solution, dried and concentrated under reduced pressure to yield a crude product which was purified by column chromatography (SiO2, hexane-ethyl acetate 4:1) to afford the title compound (610 mg, 86% yield) as a pale yellow oil.

Provenance & Evidence