Synthesis
In a 250-mL flask equipped with a mechanical stirrer, 2-oxoacetic acid hydrate (9.2 g, 0.1 mol), benzyl carbamate (15.1 g, 0.1 mol), and 1H-benzo[d][1,2,3]triazole (9.2 g, 0.1 mol) were added sequentially, and then toluene (300 mL) was added as solvent. The reaction mixture was heated to 120 °C in an oil bath with continuous stirring for 2 hours. After completion of the reaction, the mixture was filtered and the solid product was collected. The solid residue was washed with petroleum ether (3 times) and subsequently dried under vacuum to afford the target compound 2-(1H-benzo[d][1,2,3]triazol-1-yl)-2-(((benzyloxy)carbonyl)amino)acetic acid (28.6 g, 87% yield) as a white solid, which was ready for use in the subsequent reaction without further purification. The molecular ion peak m/z was measured by electrospray ionization mass spectrometry (ESI-MS) analysis: 327 [M + H]+.
References
[1] ACS Medicinal Chemistry Letters, 2015, vol. 6, # 5, p. 523 - 527
[2] Patent: WO2017/15449, 2017, A1. Location in patent: Page/Page column 51
[3] Patent: US2018/193352, 2018, A1. Location in patent: Paragraph 0205; 0206; 0207
[4] Journal of Organic Chemistry, 1990, vol. 55, # 4, p. 2206 - 2214
[5] Journal of the Chemical Society, Chemical Communications, 1989, # 6, p. 337 - 338
