Synthesis
2-((tert-butoxycarbonyl)amino)-2-methylpropanoic acid (CAN: 30992-29-1, 20 g, 98 mmol) was used as a raw material and mixed with di-tert-butyl dicarbonate (CAN: 24424-99-5, 27.67 g, 147 mmol) in acetonitrile (500 mL) and pyridine (4.6 mL) was added as a catalyst. The reaction mixture was stirred at room temperature for 20 minutes. Subsequently, ammonia (10 mL) was slowly added dropwise over 20 minutes. After the dropwise addition, the reaction mixture was continued to be stirred for 4 hours. Upon completion of the reaction, most of the solvent was removed by distillation under reduced pressure. The precipitated solid was collected by filtration and washed with acetonitrile. Finally, the solid was dried under reduced pressure to afford the target product boc-2-aminoisobutyric acid amide (17.5 g, 88% yield) as a white solid. Mass spectrometry (EI) analysis showed: m/e 225.1 [M + Na]+.
References
[1] Patent: US2012/316147, 2012, A1. Location in patent: Page/Page column 33-34
[2] Patent: WO2012/168350, 2012, A1. Location in patent: Page/Page column 80
[3] Tetrahedron, 2004, vol. 60, # 40, p. 8929 - 8936
[4] Tetrahedron Letters, 2000, vol. 41, # 50, p. 9809 - 9813
[5] Tetrahedron Letters, 2003, vol. 44, # 3, p. 463 - 466
