Synthesis
The general procedure for the synthesis of 3-anilinopropionic acid from β-propiolactone and aniline was as follows: aniline (5.00 g) was dissolved in acetonitrile (30 ml) and heated to reflux. Subsequently, β-propiolactone (3.36 ml) was added slowly and dropwise. The reflux condition was maintained and the reaction was continued for 3 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in aqueous sodium hydroxide solution and the aqueous phase was washed with ether. The pH of the aqueous phase was adjusted to 4-5 with hydrochloric acid and subsequently extracted with ether. The organic layers were combined, washed sequentially with water and saturated saline, and dried over anhydrous sodium sulfate. After filtration, the organic phase was concentrated under reduced pressure. Finally, the residue was purified by silica gel column chromatography (eluent ratio of chloroform:methanol=9:1) to afford the target product 3-anilinopropionic acid (2.08 g, 23% yield).
References
[1] Patent: EP1452526, 2004, A1. Location in patent: Page 105
[2] Journal of the American Chemical Society, 1951, vol. 73, p. 3168,3171
[3] Patent: US2008/153871, 2008, A1. Location in patent: Page/Page column 24
