Reaction Steps
To a solution of the 3-(1H-indazol-5-yl)-2-{[4-(2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-piperidine-1-carbonyl]-amino}-propionic acid (95 mg, 0.21 mmol) and N,N-diisopropylethylamine (0.14 mL, 0.82 mmol) in dimethylformamide (5 mL) was added a solution of 1,4-dioxa-8-azaspiro[4,5]decane (32 mg, 0.23 mmol) and PyBOP® (107 mg, 0.21 mmol) in methylene chloride (5 mL). The reaction mixture was stirred for 16 h at room temperature. All solvent was removed using high vacuum. The residue was subjected to flash column chromatography using methylene chloride/methanol/triethylamine (93:5:2) to give the title compound as a white solid (67 mg, 56% yield). 1H-NMR (CDCl3, 500 MHz) δ 10.52 (s, 1H), 7.97 (s, 1H), 7.54 (s, 1H), 7.37 (d, J=8.6 Hz, 1H), 7.20 (d, J=10.7 Hz, 1H), 7.16 (t, J=7.2 Hz, 1H), 7.04 (d, J=7.6 Hz, 1H), 7.01 (s, 1H), 6.94 (t, J=8.6 Hz, 1 H), 6.67 (d, J=7.6 Hz, 1H), 5.64 (d, J=7.9 Hz, 1H), 5.16 (dd, J=15.0, 6.7 Hz, 1H), 4.56-4.49 (m, 1H), 4.25 (s, 2H), 4.11 (br t, J=15.6 Hz, 2H), 3.92-3.84 (m, 4H), 3.73-3.69 (m, 1H), 3.60-3.56 (m, 1H), 3.48-3.43 (m, 1H), 3.22-3.17 (m, 1H), 3.11 (d, J=6.7 Hz, 2H), 2.90-2.85 (m, 2H), 2.68-2.60 (m, 4H), 1.67-1.61 (m, 2H), 1.54-1.49 (m, 2H). Mass spec.: 588 (MH)+.
