2-Benzyloxymethyl-2H-pyrazole-3-carbaldehyde → 1-Benzyloxymethyl-5-vinyl-1H-pyrazole

Participants

Reaction Steps

A solution of methyltriphenylphosphoniumbromide (7.85 g, 22.0 mmol) in THF (40 mL) is cooled to 0° C. then MeLi (12.2 mL, 1.6 M in ether) is added dropwise. The mixture is stirred for 1 h then a solution of 2-benzyloxymethyl-2H-pyrazole-3-carbaldehyde (3.4 g, 15.7 mmol) in THF (15 mL) is added dropwise. The reaction is stirred for an hour at 0° C., then warmed to RT over 1 h. The mixture is partitioned between aqueous NH4Cl and EtOAc and the organic layer is concentrated. Chromatography (10-15% EtOAc/hexane) affords the title compound as a yellow oil: (M+1)+=215.

Provenance & Evidence