Synthesis
To a mixture of tert-butylamine (1.57 liters) and toluene (1.35 liters) was added tert-butyl bromoacetate (420 ml) at 45-50C. The temperature was raised to 75C in 1 hour. The mixture was stirred at 50-60C for 1 h. The temperature was raised to 75C within 1 h. After 2 h at 75C, the mixture was cooled to -12+3C and allowed to stand for 1 h. The mixture was then purified by filtration. The solid was collected by filtration and the filtrate was concentrated to a volume of 825 mL by distillation (30-40C, 25-35 mm Hg). The resulting concentrate was cooled to 20-25C and 6N HCl (1.45 kg) was added. after 3 h, the phases were separated and the aqueous phase was concentrated to 590 mL by distillation (30-40C, 25-35 mm Hg). Isopropanol (2.4 l) was added and the mixture was concentrated to 990 ml by distillation (15-20C, 10-20 mm Hg). The resulting slurry was cooled to -12+3C within 30 minutes and allowed to stand for 1 hour. The solid was collected by filtration, washed with i-PrOH and dried (45+3C, 10 mm Hg) for 24 h to give (407.9 g, 86%) of the desired product.N-tert-butylglycine hydrochloride, yield 407.9 g, 86%.
