A Rapid and Efficient Microwave-Assisted Synthesis of Substituted 3-Phenylpropionic Acids from Benzaldehydes in Minutes

A convenient, inexpensive, and efficient synthesis of 3-phenylpropionic acids (1a–1f) by reacting benzaldehyde (2a–2f) and malonic acid in acetic acid and piperidine into cinnamic acid (3a–3f) in 77 to 89% followed by its reduction with PdCl2 in the biphase of formic acid and aqueous sodium hydroxide is reported under microwave irradiation which utilizes short reaction time ranging 5 to 7 min to provide 1a–1f in moderate to high yield (69–86%) depending upon methoxy, methylenedioxy, and hydroxy groups present at the phenyl ring.