141-82-2

587-04-2

1866-38-2

GENERAL METHOD: Under stirring conditions, 6.76 g (65 mmol) of malonic acid was dissolved in a mixed solution of 5 mL of pyridine and 0.5 mL of piperidine. Subsequently, 3-chlorobenzaldehyde (50 mmol) was slowly added at 85°C. The reaction mixture was stirred continuously for 6 hours, during which the progress of the reaction was monitored by thin layer chromatography (TLC) to confirm complete consumption of the feedstock. Upon completion of the reaction, the mixture was cooled to room temperature and neutralized with 10% hydrochloric acid solution under ice bath conditions, at which point a white solid was observed to precipitate. The solid product was collected by filtration and washed three times with ice water to remove impurities. Finally, the target product 3-chlorocinnamic acid (2a-h) was obtained by recrystallization and purification using aqueous ethanol (1:1, v/v).