24424-99-5

2615-25-0

177906-48-8

Example 17. General procedure for the synthesis of tert-butyl trans-(4-aminocyclohexyl)carbamate (SB1-E-21-1) from di-tert-butyl dicarbonate and trans-1,4-cyclohexanediamine: To a methanol (100 mL) solution of SM-21-1 (2.0 g, 17.5 mmol) was slowly added dropwise a methanol (60 mL) solution of di-tert-butyl dicarbonate (1.1 g, 5.04 mmol). ) solution in methanol (60 mL) for 30 minutes. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the solvent was removed by concentration under reduced pressure. Water (50 mL) was added to the residue and stirring was continued for 20 minutes at room temperature, followed by filtration. The filtrate was extracted with ethyl acetate (120 mL x 2), and the organic phases were combined and washed sequentially with water (50 mL x 2) and saturated saline (50 mL x 2). The organic phase was dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove the solvent to afford the target product SB1-E-21-1 (off-white solid, 900 mg, 83% yield).