A mixture of N-TFA compound (480 mg, 0.88 mmol) and potassium carbonate (1.21 g, 8.8 mmol) in MeOH/H2O (25mL/10mL) was stirred at rt overnight. The mixture was concentrated in vacuo, and the residue was partitioned between H2O and EtOAc. The two layers were separated, and the aqueous layers was re-extracted with EtOAc (2x). The combined organic extracts were washed with the brine, dried over MgSO4, filtered, and concentrated in vacuo. The residue was suspended in Et2O and 2M HCl in Et2O was added. The suspension was concentrated to dryness to yield 410 mg (95%) of the product as a white powder.
Patent reference: WO2011087652