Diethyl chlorophosphate → 1-(Diethoxyphosphorylmethylsulfonyl)-4-(4-methyl-2-pyridyl)piperazine

Participants

Reaction Conditions

Reaction Steps

1-(4-Methyl-2-pyridyl)-4-methylsulfonyl-piperazine (1.16 g, 4.54 mmol) was dissolved in anhydrous THF (80 ml) and cooled under nitrogen to −78° C. Lithium bis(trimethylsilyl)amide (1M in THF, 14 ml, 14 mmol) was added dropwise and the mixture was stirred at −78° C. for one hour. Diethyl chlorophosphate (3.1 g, 18 mmol) was added dropwise and stirring was continued for one hour at −78° C., after which the mixture was allowed to reach room temperature over three hours. A saturated solution of ammonium chloride was added and the mixture was extracted with DCM (3×), the combined organic layers were dried (sodium sulfate), concentrated under reduced pressure and the residue was purified by column chromatography (silica, gradient from 0 to 6% methanol in DCM) to give 1.44 g of a light-brown oil (3.68 mmol, yield 81%) MS (ESI) m/z=392.1 [M+1]+.

Provenance & Evidence