Reaction Steps
To a solution of (1S,8aS)-N-((R)-1-(3,5-bis(trifluoromethyl)phenyl)ethyl)-7,7-bis(2-hydroxyethyl)-N-methyl-6-oxo-1-o-tolylhexahydropyrrolo[1,2-a]pyrazine-2(1H)-carboxamide (70 mg, 0.11 mmol) in 5 mL of DCM, was added MsCl (38 mg, 0.33 mmol) at 0° C. The mixture was stirred for 1.5 h, and concentrated in high vacuum. The residue was treated with mixture of H2O (5 mL) and TEA (0.5 mL) and then heated to 65° C. until the reaction was completed. The reaction mixture was extracted with DCM (2×15 mL) and the organic layers were dried over anhydrous Na2Sa4 and then concentrated in high vacuum. The residue was purified by Prep-HPLC to give the title compound (15 mg, yield: 23%). 1H NMR (400 MHz, CDCl3) δ ppm 7.71 (s, 1H), 7.46 (s, 2H), 7.22 (m, 4H), 5.47 (d, J=7.0 Hz, 1H), 4.08 (d, J=12.8 Hz, 1H), 3.95 (d, J=9.7 Hz, 2H), 3.81 (dd, J=7.6, 4.0 Hz, 1H), 3.65 (d, J=9.1 Hz, 1H), 3.36 (dd, J=13.4, 6.3 Hz, 2H), 3.20 (d, J=11.6 Hz, 1H), 3.05 (td, J=12.3, 3.4 Hz, 1H), 2.91 (dt, J=11.8, 5.9 Hz, 1H), 2.63 (s, 3H), 2.46 (s, 3H), 2.11 (dd, J=17.6, 6.9 Hz, 1H), 1.89 (dd, J=13.1, 7.2 Hz, 1H), 1.79 (dd, J=17.0, 7.0 Hz, 1H), 1.49 (s, 2H), 1.31 (t, J=8.1 Hz, 6H), 1.18 (s, 3H), 0.86 (s, 2H); m/z (ES+): 598 [M+H]+.