Synthesis
General procedure: Propionic anhydride (300 mmol, 1.6 eq.) was slowly added to a reaction vial containing potassium carbonate (224 mmol, 1.2 eq.) at 0 °C. After stirring for 5 min, benzaldehyde (186 mmol, 1.0 eq.) was added dropwise to the mixture. The reaction mixture was heated to reflux and maintained for 12 hours. Upon completion of the reaction, the mixture was cooled to room temperature using an ice bath, followed by addition of water (appropriate amount) and solid Na2CO3 (30 g) to the reaction mixture. The resulting yellow precipitate was collected by filtration and the filtrate was acidified to pH 6.0 with concentrated HCl to precipitate a solid product of 2-methyl-3-phenylpropenoic acid.
References
[1] Medicinal Chemistry Research, 2004, vol. 13, # 8-9, p. 660 - 676
[2] European Journal of Medicinal Chemistry, 2013, vol. 62, p. 632 - 648
[3] American Chemical Journal, 1906, vol. 36, p. 533
[4] Journal of the Chemical Society, 1877, vol. 31, p. 409
[5] Journal of the Chemical Society, 1878, vol. 33, p. 215