Cesium carbonate → tert-butyl 4-{3-[(3R)-3-{[3-methoxy-1-{5-[2-(2-{[(4-methylphenyl)sulfonyl]oxy}ethoxy)phenyl]pyridin-3-yl}-3-oxopropyl]carbamoyl}piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate

Participants

Reaction Steps

108.0 mg (0.17 mmol) Tert-butyl 4-{3-[(3R)-3-({1-[5-(2-hydroxyphenyl)pyridin-3-yl]-3-methoxy-3-oxopropyl}carbamoyl)piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate (example 8d) were dissolved in 6.7 ml N,N-dimethylformamide. 170 mg (0.52 mmol) cesium carbonate and 96.4 mg (0.26 mmol) ethylene glycol bis-p-toluenesulfonate were added. The mixture was stirred at room temperature for 68 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. Chromatography over 10 g silica gel (dichloromethane/ethanol 100/0-90/10) gave 55 mg (37%) tert-butyl 4-{3-[(3R)-3-{[3-methoxy-1-{5-[2-(2-{[(4-methylphenyl)sulfonyl]oxy}ethoxy)phenyl]pyridin-3-yl}-3-oxopropyl]carbamoyl}piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate.

Provenance & Evidence