Potassium Carbonate → Bepotastine Ethyl Ester

Participants

Reaction Steps

In 15 ml of acetone was dissolved 1.33 g (4.39 mmol, optical purity: 99.4% e.e.) of (S)-(−)-4-[(4-chlorophenyl) (2-pyridyl)methoxy]piperidine obtained according to Reference example 1, then, 1.03 g (5.28 mmol) of ethyl 4-bromobutanoate and 0.73 g (5.28 mmol) of potassium carbonate were added, and the mixture was refluxed under stirring for 7 hours. Insolubles were filtered off and the filtrate was concentrated under reduced pressure. The resulting slightly yellowish oily product was purified by silica gel column chromatography using a mixed solvent of chloroform and methanol (volume ratio: 30:1) as an eluent. Fractions containing the isolated objective compound were concentrated under reduced pressure to afford 1.71 g of ethyl (S)-4-[4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidino]-butanoate as an oily product (Yield: 93.4%, optical purity: 99.4% e.e.). [α]D25 −6.60° (c=1, MeOH)

Provenance & Evidence