A mixture the product of Example 1, Step E (0.07 g; 0.85 mmol), azetidine-3-methylcarboxylate hydrochloride (0.03 g; 0.199 mmol) and DIPEA (0.035 ml, 0.2 mmol) in 1,2-dichloroethane (1 ml) and methanol (MeOH) (3 ml) was sonicated for 30 min at room temperature, then evaporated to dryness. The yellowish residue was suspended in 1,2-dichloroethane (1 ml) and NaBH(OAc)3 (0.12 g; 0.57 mmol) was added, followed by AcOH (0.01 ml). This was stirred for 1 h at room temperature and diluted to 15 ml with EtOAc, washed with 10% KOH (2×3 ml); brine, dried over anhydrous MgSO4, filtered and the filtrate evaporated to dryness. The residue was purified by FCC (SiO2, EtOAc) to give the title compound (0.06 g; 68%), as creamy syrup. 1H-NMR (CDCl3) 8.33 (d, 1H, J=3 Hz); 8.06 (dd, 1H, 3, 9 Hz); 7.78 (dd, 1H, J=3, 9 Hz); 6.87 (d, 1H, J=2 Hz); 6.63 (s, 1H); 4.14-4.22 (m, 4H); 3.6-3.7 (m, 5H); 3.48-3.34 (m, 2H); 1.49 (m, 6H).
