Example 1
The acid (152 mg, 0.801 mmol) was added to a solution of CDI (130 mg, 0.801 mmol) in dry THF (1 mL) at RT under N2. The mixture was stirred for 90 min at RT, after which time it was added over 25 min to a solution of the amine (200 mg, 0.400 mmol) in THF (1.5 mL) at RT under N2. The reaction mixture was stirred at RT for 16 h. Additional acid (152 mg, 0.801 mmol) and CDI (130 mg, 0.801 mmol) in dry THF (1 mL) was added slowly at RT. The reaction mixture was stirred at RT for 2 h. TFA (1 mL, 26.1 mmol) was added at RT, and the mixture was stirred 22 h. Additional TFA (1 mL, 26.1 mmol) was added, and the mixture was stirred 18 h. The reaction mixture was then stirred at 80 C for 160 min. The mixture was diluted with H2O and extracted with EtOAc. The org phase was washed with brine, dried (MgSO4), and concentrated to give an oil. The oil was purified by Prep LC (12 g silica, 100% DCM to 90:9:1 DCM/MeOH/NH3) to provide the product as a white solid. [158 mg, 80%]
[Patent Reference: WO2015144799, page 287, (18.8 MB)]