Cesium carbonate → tert-butyl 4-{3-[(3R)-3-({3-methoxy-1-[4-(2-{[(4-methylphenyl)sulfonyl]oxy}ethoxy)phenyl]-3-oxopropyl}carbamoyl)piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate

Participants

Reaction Steps

100 mg (0.18 mmol) Tert-butyl 4-[3-((3R)-3-{[1-(4-hydroxyphenyl)-3-methoxy-3-oxopropyl]carbamoyl}piperidin-1-yl)-3-oxopropyl]piperidine-1-carboxylate (example 2b) were dissolved in 7 ml N,N-dimethylformamide. 179 mg (0.55 mmol) cesium carbonate and 102 mg (0.28 mmol) ethylene glycol bis-p-toluenesulfonate were added. The mixture was stirred at room temperature for 48 hours and concentrated. The remainder was taken up with saturated ammonium chloride solution and ethyl acetate. The aqueous phase was extracted with 3×20 ml ethyl acetate. The extracts were dried over sodium sulfate and concentrated to yield 195 mg. Chromatography over 5 g silica gel (dichloromethane/ethanol 100/0-95/5) gave 95 mg (63%) tert-butyl 4-{3-[(3R)-3-({3-methoxy-1-[4-(2-{[(4-methylphenyl)sulfonyl]oxy}ethoxy)phenyl]-3-oxopropyl}carbamoyl)piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate.

Provenance & Evidence