Triethyl phosphonoacetate → tert-Butyl 4-(2-ethoxy-2-oxoethylidene)piperidine-1-carboxylate

Participants

Reaction Steps

To a solution of 9.1 g of 60% oily sodium hydride in 200 ml of tetrahydrofuran, 38.0 ml of ethyl diethylphosphonoacetate was added dropwise under cooling with ice, stirred for 20 minutes, and thereafter a solution of 31.4 g of 1-t-butoxycarbonyl-4-piperidone in 500 ml of tetrahydrofuran was added dropwise, followed by 40 minutes' stirring at the same temperature. The reaction liquid was diluted with ethyl acetate, washed successively with aqueous ammonium chloride solution, water and saturated brine, and dried over anhydrous sodium sulfate. Distilling the solvent off under reduced pressure, the residue was recrystallized from methanol to provide 33.5 g of the title compound.

Provenance & Evidence