Synthesis
L-norvaline (160 g, 1.34 mol) was dissolved in 28.5% hydrochloric acid solution (278 g) and diluted with methanol (500 ml). The reaction mixture was refluxed for 6 hours under the protection of inert atmosphere. After completion of the reaction, the solvent was removed by co-evaporation with toluene. The residue was treated with tert-butyl methyl ether (800 ml) at 50 °C. The resulting suspension was stirred at room temperature and subsequently filtered. The resulting white solid was washed with tert-butyl methyl ether to give 216 g of L-norvaline methyl ester hydrochloride in 97% yield.
References
[1] Angewandte Chemie, 1992, vol. 104, # 1, p. 97 - 99
[2] Synthesis, 2010, # 17, p. 2915 - 2921
[3] Patent: WO2013/136265, 2013, A1. Location in patent: Page/Page column 21-22
[4] Patent: WO2004/33434, 2004, A1. Location in patent: Page 34
[5] Heterocycles, 1998, vol. 47, # 2, p. 765 - 780
