Hydrochloric Acid → p-Bromocinnamic acid

Participants

Reaction Steps

A solution of 4-bromobenzaldehyde, 1 (110 g, 0.59 mol), malonic acid (112.5 g, 1.189 mol), piperidine (11 mL) in pyridine (350 mL) was heated to 80° C. for 1 h, then refluxed for 3 h. Then the reaction mixture was cooled to room temperature, poured into a large beaker filled with cold water, and then acidified (pH<3) by slowly adding 25 mL of concentrated hydrochloric acid. The resulting precipitate was filtered and washed with cold water. The crude product was dissolved in aqueous sodium hydroxide, acidified (pH<3) (1:1 hydrochloric acid/water), filtered, and washed (cold water). The solid was dried in vacuo (60-70° C.) to give 2 (118.8 g, 88%).

Provenance & Evidence