Trans-4-(Boc-amino)cyclohexanecarboxylic acid

24424-99-5

1776-53-0

53292-90-3

1. To a stirred aqueous solution (10 mL) of trans-4-aminocyclohexanecarboxylic acid (1 g, 6.98 mmol) in tert-butanol (10 mL) and NaOH (0.307 g, 7.68 mmol) at 0 °C was slowly added di-tert-butyl dicarbonate (1.7 g, 7.68 mmol). 2. The reaction mixture was gradually warmed to room temperature with continuous stirring overnight. 3. Upon completion of the reaction, hexane (50 mL) was added to the mixture and the pH was adjusted to about 6 with 6N HCl. 4. 4. The reaction mixture was extracted with ethyl acetate (3 x 50 mL), the organic phases were combined and washed with brine solution (25 mL). 5. The organic phase was concentrated under pressure to give the white solid product cis-4-((tert-butoxycarbonyl)amino)cyclohexanecarboxylic acid (1.4 g, 82.8% yield). 6. The product was confirmed by mass spectrometry (ES-), m/z 242 [M-H]-.