Synthesis
The general procedure for the synthesis of phthaloyl-L-alanine from L-alanine and N-ethoxycarbonylphthalimide was as follows: to a stirred aqueous solution (100 mL) of L-alanine (8.9 g, 100.00 mmol) and Na2CO3 (10.6 g, 100.00 mmol) was added slowly N-ethoxycarbonylphthalimide. After the reaction for 1.5 h, the reaction mixture was slowly acidified to pH = 1-2 with aqueous 1N HCl. The precipitate was collected by filtration to afford a white solid phthaloyl-L-alanine 17.37 g in 79.3% yield. The melting point of the product was 145.8-146.6 °C. 1H NMR (CDCl3, 400 MHz) δ: 1.71 (s, 3H, CH3), 5.02 (q, J = 7.4 Hz, 1H, CH), 7.69-7.75 (m, 2H, Ar-H), 7.82-7.88 (m, 2H, Ar-H). mS (ESI): m/z 218.2 [M+H]+.
References
[1] Angewandte Chemie - International Edition, 2013, vol. 52, # 51, p. 13588 - 13592
[2] Angew. Chem., 2013, vol. 125, # 51, p. 13833 - 13837,5
[3] Chemical Communications, 2017, vol. 53, # 47, p. 6351 - 6354
[4] Synthetic Communications, 1983, vol. 13, # 4, p. 311 - 318
[5] Synthetic Communications, 1983, vol. 13, # 5, p. 393 - 402
