To a solution of N-hydroxy-2-phenyl-acetamidine (0.27 mmol, 3 equiv, this and the other amidine intermediates of the present invention were prepared as described in J. Med. Chem. 1993, 1529-1538) in anhydrous tetrahydrofuran (4 mL) was added sodium hydride (0.27 mmol, 3 equiv) under nitrogen. The mixture was heated at 65° C. for 30 min before addition of a solution of (±)-2-(7-methyl-1H-indazol-5-ylmethyl)-4-oxo-4-[4-(2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-piperidin-1-yl]-butyric acid methyl ester (0.09 mmol, 1 equiv) in tetrahydrofuran (3 mL). The reaction mixture was heated at 65° C. overnight. Tetrahydrofuran was removed in vacuo and the reaction mixture was taken up in methylene chloride, washed with water (3×4 mL), dried over sodium sulfate and concentrated. Flash chromatography on silica gel using methanol/methylene chloride from 0 to 10% gave an impure product. The final product was obtained by preparative HPLC in 27% yield. LC/MS: tR=1.60 min, 590 (MH)+. 1H-NMR (400 MHz, CD3OD) δ 7.92 (1H, s), 6.90-7.25 (10H, m), 6.74 (1H, d, J=8.00 Hz), 4.32-4.57 (2H, m), 4.24-4.29 (2H, m), 3.79-4.06 (5H, m), 2.79-3.31 (5H, m), 2.57 (1H, m), 2.44 (3H, s), 1.50-1.82 (4H, m).
