Toluene → HCID 68153913, compound

Participants

Reaction Conditions

Reaction Steps

4-Ethoxy-4′-formyl-2,3-difluoro-1,1′-biphenyl (s49) (30.0 g), ethyl diethylphosphonoacetate (30.8 g) and toluene (200 ml) were placed in a reaction vessel under an atmosphere of nitrogen, and cooled to 0° C. Sodium ethoxide in ethanol solution (20%; 46.7 g) was added at the same temperature, and the stirring was continued for another 2 hours. After the reaction mixture had been returned to 25° C., the stirring was continued for another 2 hours. The reaction mixture was treated with water, and the aqueous layer was extracted with toluene. The combined organic layers were washed with water, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by column chromatography with a mixed solvent of toluene and heptane (toluene:heptane=2:1 by volume) as an eluent and silica gel as a stationary phase powder. The purified product was dissolved in 2-propanol (150 ml), to which Pd/C (1.5 g) was added. The mixture was stirred at room temperature under a hydrogen atmosphere until hydrogen absorption had ceased. After the reaction had been completed, Pd/C was removed, and then solvent was distilled off. The residue was purified by column chromatography with toluene as an eluent and silica gel as a stationary phase powder to give ethyl 3-(4′-ethoxy-2′,3′-difluoro-(1,1′-biphenyl)-4-yl)propionate (s50) (28.9 g). The yield based on the compound (s49) was 75.6%.

Provenance & Evidence