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

Participants

Reaction Steps

82.0 mg (0.13 mmol) tert-butyl 4-{3-[(3R)-3-({1-[5-(4-hydroxyphenyl)pyridin-3-yl]-3-methoxy-3-oxopropyl}carbamoyl)piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate (example 7a) were dissolved in 5.1 ml N,N-dimethylformamide. 129 mg (0.40 mmol) cesium carbonate and 73.2 mg (0.20 mmol) ethylene glycol bis-p-toluenesulfonate were added. The mixture was stirred at room temperature for 20 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 64 mg (59%) tert-butyl 4-{3-[(3R)-3-{[3-methoxy-1-{5-[4-(2-{[(4-methylphenyl)sulfonyl]oxy}ethoxy)phenyl]pyridin-3-yl}-3-oxopropyl]carbamoyl}piperidin-1-yl]-3-oxopropyl}piperidine-1-carboxylate.

Provenance & Evidence