Water → tert-Butyl diethylphosphonoacetate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl diethylphosphonoacetate (75.0 g, 297.32 mmol) was added dropwise to a suspension of sodium hydride (8.03 g, 334.58 mmol) in DMF (450 mL) at 0° C. under nitrogen. The mixture was stirred at 0° C. for 0.5 h and at room temperature for 0.5 h. 4-bromomethyl-piperidine-1-carboxylic acid tert-butyl ester (20.68 g, 74.34 mmol) in DMF (50 mL) was added dropwise to the reaction mixture and the reaction was heated to 60° C. and stirred for 16 h. The reaction was cooled to room temperature, poured into H2O and extracted with ethyl acetate. The organic layers were combined and washed with water. The organic layer was dried, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography (ethyl acetate/hexane, 3:7) to give 4-[2-tert-Butoxycarbonyl -2-(diethoxy-phosphoryl)-ethyl]-piperidine-1-carboxylic acid tert-butyl ester and unreacted t-butyl diethylphosphonoacetate. The product was 47% pure by HPLC. The product was further purified by vacuum distillation to give 77% purity. This mixture was taken on to the next reaction.

Provenance & Evidence