3-Chlorobenzaldehyde → Ethyl 3-(3-chlorophenyl)-2-propenoate

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Reaction Conditions

Reaction Steps

In a 2 l three necked flask fitted with mechanical stirrer and dropping funnel under inert atmosphere, 106.2 g (755 mmoles, 1 eq) of 3-chlorobenzaldehyde are dissolved in 1 l of THF and cooled down to 0° C. 341.9 g (980 mmoles, 1.3 eq) of ethyl (triphenylphosphoranylidene)acetate are then added under efficient stirring, the temperature raising to 10° C. The mixture is kept under stirring one hour at 0° C., and then overnight at room temperature. The mixture is concentrated to dryness, the residue suspended in diethyl ether, the triphenylphosphine oxide is filtered off and the filtrate concentrated to dryness. The residue is purified by PrepLC (1 kg SiO2, pet. ether/EtOAc, 75:35) to give 191.8 g of pure 375, 92% yield. 1H NMR (250 MHz, (CD3)2SO): 1.30 (t, 3H), 4.25 (q, 2H), 6.70 (d, 1H), 7.40 (m, 2H), 7.50-7.70 (m, 2H), 7.85 (s(broad), 1H).

Provenance & Evidence