4-Chlorobenzaldehyde → 2-Propenoic acid, 3-(4-chlorophenyl)-, ethyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of 4-chlorobenzaldehyde (28 g) and (carboethoxymethylene)triphenylphosphorane (73 g) in toluene (500 mL) was refluxed for 2 hours. The reaction was cooled to room temperature and concentrated under vacuum to a total volume of 150 mL. Then pure hexane (500 mL) was added and the mixture was left for 18 hours at room temperature. The solid (triphexylphosphine oxide) was filtered, rinsed with hexane and the filtrate evaporated to give crude product which was distilled at 0.5 mm Hg, and the fraction boiling at 130° C. was collected to give ethyl 4-chlorocinnamate, which was reduced as follows: the cinnamate (21 g) was hydrogenated in EtoAc (300 mL) in the presence of 5% Pd on C (2 g) for 3 hours at atmospheric pressure. After completion, the reaction mixture was filtered through a celite pad, rinsed with EtOAc and the filtrate evaporated to dryness to give the title product as an oil.

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