Dicyclohexylcarbodiimide → 2-(4-Phenoxyphenoxy)ethyl-4,4-difluorobut-3-enoate

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Reaction Conditions

Reaction Steps

A solution of 3.0 g of 4,4-difluorobut-3-enoic acid in 50 ml of diethyl ether is treated with 0.36 g of 4-pyrrolidinopyridine and 5.66 g of 2-(4-phenoxyphenoxy)ethanol, and the mixture is cooled to 0° C. A total of 5.58 g of N,N'-dicyclohexylcarbodiimide are added in portions at a temperature of between 0° C. and +5° C., the ice-cooling is removed, and the reaction mixture is allowed to come to room temperature in the course of 16 hours, with stirring. The N,N'-dicyclohexylurea which has precipitated as a solid is separated off and discarded. The supematant solution is evaporated. The residue obtained is purified by column chromatography on silica gel (eluent: hexane/ethyl acetate, 9:1). This gives pure 2-(4-phenoxyphenoxy)ethyl 4,4-difilorobut-3-enoate in the form of an oil (refractive index nD23 : 1.5315).

Provenance & Evidence