4-methoxycinnamic acid synthesis : In a 25-mL, roundbottomed flask, 4-methoxybenzaldehyde (0.804 mL, 6.61 mmol) (3), malonic acid (1.75 g, 16.8 mmol), and β-alanine (0.10 g, 1.12 mmol) were dissolved in pyridine (3.0 mL, 37.1 mmol) and heated under reflux for 90 minutes. After cooling to room temperature, the reaction mixture was placed in an ice bath and 8.0 mL of concentrated HCl was slowly added. The resulting white precipitate was collected by vacuum filtration, washed with cold water (2 x 10mL) and dried thoroughly. The product was recrystallized from absolute ethanol (~20 mL).
Synthesis of 4-methoxycinnamic acid
