Synthesis
Benzyl chloroformate (Benzyl chloroformate) was slowly added to a solution of tert-butyl carbazate (tert-Butyl carbazate, 75 g, 567 mmol) in dichloromethane (Dichloromethane, 2.0 L) at 0 °C, and the addition time was controlled to be within 45 min. After the addition was completed, the reaction mixture was stirred at 0 °C overnight and allowed to warm up to room temperature naturally in an ice bath. Upon completion of the reaction, the reaction mixture was carefully poured into saturated sodium bicarbonate solution (1 L) for neutralization, followed by extraction with dichloromethane. The organic layer was washed with water and dried with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure to afford the crude product 2-(tert-butyl)hydrazine-1,2-dicarboxylic acid-1-benzyl ester (148 g, 556 mmol, 98% yield) as a viscous oil. After preliminary analysis, the purity of the product meets the requirements for subsequent use without further purification.
References
[1] Patent: WO2008/65500, 2008, A2. Location in patent: Page/Page column 67
[2] Tetrahedron, 2010, vol. 66, # 49, p. 9538 - 9544
[3] Tetrahedron Letters, 1992, vol. 33, # 36, p. 5209 - 5212
[4] Tetrahedron Letters, 2007, vol. 48, # 33, p. 5767 - 5770
[5] Journal of the American Chemical Society, 2004, vol. 126, # 21, p. 6759 - 6764
