84228-93-3

110-89-4

872-85-5

84228-93-3

A. Preparation of (E)-3-(pyridin-4-yl)acrylic acid 4-Pyridinecarboxaldehyde (18.96 g, 0.177 mol) and malonic acid (55.3 g, 0.53 mol) were dissolved in 200 mL of pyridine. Piperidine (5.25 mL, 0.053 mol) was added to the solution and the reaction mixture was subsequently heated to reflux for 6 hours. After completion of the reaction, the mixture was cooled in an ice bath and the precipitated white solid was separated by filtration and washed with ether and dried to give 20.1 g of (E)-3-(pyridin-4-yl)acrylic acid. The filtrate was further concentrated, filtered again and washed with aqueous ethyl ether to afford an additional 2.2 g of product in a total yield of 84%.