Sodium Carbonate → Tert-butyl 1-(3-bromo-5-fluoropyridin-4-yl)piperidine-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 3 L flange flask equipped with a thermometer, condensor, nitrogen line and overhead stirrer was heated at 40° C. (external) then charged with cyclohexanol (750 mL), disodium carbonate (129.8 g, 1.225 mol), 3-bromo-4-chloro-5-fluoro-pyridine (Hydrochloric Acid 18) (137.5 g, 556.8 mmol) and tert-butyl piperidine-4-carboxylate (123.8 g, 668.2 mmol) rinsed in with cyclohexanol (350 mL). Mixture was heated to 120° C. internal temperature overnight (18 h). Reaction mixture was removed from hotplate and allowed to cool to room temperature. Water (687.5 mL) and EtOAc (687.5 mL) were added, stirred for 10 mins then transferred to separating funnel Additional EtOAc (1.238 L) was added, mixed and aqueous phase was removed. Organic phase was further washed with water (687 mL), aqueous phase removed, organic layer collected. Aqueous phases were combined and back extracted with EtOAc (687.5 mL), aqueous layer removed and organic phase combined with other organics. Organics concentrated in vacuo (water bath temp=60° C., vacuum down to 2 mBar) leaving a viscous brown oil.

Provenance & Evidence