To a solution of the product from Example 24A (0.48 g, 2.00 mmol) in dichloromethane was added 2-(2-oxo-3,3-diphenylpyrrolidin-1-yl)acetic acid (Example 1C, 0.59 g, 2.00 mmol) under nitrogen. To the reaction was added N1-((ethylimino)methylene)-N3,N3-dimethylpropane-1,3-diamine hydrochloride (0.77 g, 4.00 mmol) and N,N-dimethylpyridin-4-amine (0.024 g, 0.20 mmol), and the reaction mixture was stirred overnight at room temperature. The reaction was concentrated, and the residue was partitioned in ethyl acetate:water (8:2). The organic layer was separated, washed with water and then brine, dried over MgSO4, filtered, and concentrated. Silica gel chromatography eluting with 3% methanol/dichloromethane gave the title compound. 1H NMR (300 MHz, CDCl3) δ ppm 7.13-7.37 (m, 20H), 4.16 (s, 2H), 4.11 (s, 2H), 3.33-3.40 (m, 2H), 3.24 (t, J=6.4 Hz, 2H), 2.63 (t, J=6.4 Hz, 2H), 2.39-2.46 (m, 2H), 1.29-1.37 (m, 2H); MS (DCI+) m/z 515 (M+H)+.
