Triethyl phosphonoacetate → Ethyl 3-[4-(trifluoromethyl)phenyl]propanoate

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Reaction Conditions

Reaction Steps

Dimethoxyethane 700 ml was added to 60% sodium hydride 24.8 g (620 mmol), the mixture was stirred at room temperature while a solution of ethyl diethylphosphonoacetate 139 g (620 mmol) in dimethoxyethane (100 ml) was added dropwise. After the generation of hydrogen gas was stopped, the solution was cooled to 10° C., and a solution of 4-trifluoromethylbenzaldehyde 100 g (574 mmol) in dimethoxyethane (100 ml) was added dropwise keeping the liquid temperature below 25° C. After addition, the mixture was stirred for 30 minutes, the reactant was added to water one liter, and the product was extracted with diethylether. The extract was washed with a sodium chloride aqueous solution, and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (eluent: heptane/ethyl acetate=3/1). Such obtained purified material was hydrogenated in the presence of 5% palladium carbon as a catalyst in ethanol 300 ml. The catalyst was filtered off, the solvent was distilled off at reduced pressure to obtain 3-(4-trifluoromethylphenyl)propionic acid ethylester 81.0 g (329 mmol). The yield was 57.3% from 4-trifluoro methylbenzaldehyde.

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