Sodium hydride → 1,1-dimethylethyl 4-[3-(methoxycarbonyl)-1H-pyrazol-1-yl]-1-piperidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

A suspension of 60% dispersion of sodium hydride in mineral oil (192 mg, 4.8 mmol) in 20 mL of N,N-dimethylformamide was cooled to 0° C., and methyl 3-pyrazolecarboxylate (605.37 mg, 4.8 mmol) was gradually added with stirring in nitrogen atmosphere. The reaction mixture was stirred at room temperature for 0.5 h and cooled again to 0° C. A solution of 1,1-dimethylethyl 4-[(methylsulfonyl)oxy]-1-piperidine-carboxylate (1.18 g, 4 mmol) (i.e. the product of Example 18, Step A) in 5 mL of N,N-dimethylformamide was gradually added to the reaction mixture. The resulting mixture was stirred for 5 days at 60° C. The reaction mixture was poured in ice water and extracted with ethyl acetate. The organic layer was dried (MgSO4), evaporated in vacuo, and purified by medium-pressure liquid chromatography on silica gel eluting with 0-10% methanol in ethyl acetate as eluant to give 290 mg of the title compound as a white solid.

Provenance & Evidence