N,N-Dimethylaniline → (2e)-3-{2,6-Difluoro-4-[(isopropoxycarbonyl)amino]phenyl}prop-2-enyl diazoacetate

Participants

Reaction Conditions

Reaction Steps

Glyoxylic acid chloride p-toluenesulfonylhydrazone (4.64 g, 17.8 mmol) was added to a suspension of isopropyl 3,5-difluoro-4-[(1E)-3-hydroxyprop-1-enyl]phenylcarbamate (2.68 g, 9.89 mmol) in dichloromethane (66 mL). The mixture was cooled to 0° C. and treated with N,N-dimethylaniline (2.26 mL, 17.8 mmol). After 30 minutes, triethylamine (6.89 mL, 49.5 mmol) was added and the mixture stirred 30 minutes at 0° C. and 15 minutes at room temperature. The reaction mixture was then concentrated to ca. 15 mL and 50 mL of water added. The mixture was extracted with two portions of diethyl ether and the combined organic solutions washed with saturated NaHCO3, brine, and dried (MgSO4), filtered and concentrated. Purification by column chromatography (0-25% ethyl acetate-hexane) provided the title compound a yellow solid.

Provenance & Evidence