Reaction Steps
A mixture of tert-butyl {1-[4-(2-bromo-9H-imidazo[1,2-d]pyrido[2,3-b][1,4]benzodiazepin-3-yl)phenyl]cyclobutyl}carbamate (50 mg, 0.09 mmol), [4-(3-ethoxy-3-oxopropyl)phenyl]boronic acid (40 mg, 0.18 mmol), bis(di-tert-butyl(4-dimethylamino phenyl)phosphine)dichloropalladium(II) (6.3 mg, 0.01 mmol) and K3PO4 (72 mg, 0.27 mmol) in DMF/water (0.9 mL, 6:1, v/v) was heated at 160° C. under microwave irradiation for 1 hour. After cooling to room temperature, the mixture was diluted with EtOAc and washed with water (×3). The organic layer was dried over anhydrous Na2SO4 and concentrated. The residue was purified by HPLC. To the fraction, conc. HCl (3 ml) and methanol (3 ml) were added and the residue was evaporated after 24 h. The residue was purified by HPLC to give the titled compound as a white solid (24 mg, 42%). 1HNMR (DMSO-d6) 400 MHz δ: 8.54 (s, 1H), 8.22 (s, 1H), 8.07 (dd, J=4.6, 1.7 Hz, 1H), 7.94 (dd, J=7.7, 1.4 Hz, 1H), 7.47 (d, J=8.6 Hz, 2H), 7.42 (d, J=8.6 Hz, 2H), 7.34 (td, J=7.7, 1.5 Hz, 1H), 7.28 (dd, J=8.0, 1.1 Hz, 1H), 7.19 (d, J=8.0 Hz, 2H), 7.14 (d, J=8.6 Hz, 2H), 7.11 (t, J=8.0 Hz, 1H), 6.86 (dd, J=8.0, 1.1 Hz, 1H), 6.72 (dd, J=7.7, 4.9 Hz, 1H), 3.58 (s, 3H), 2.83 (t, J=7.4 Hz, 2H), 2.63 (t, J=8.0 Hz, 2H), 2.43-2.36 (m, 2H), 2.20-2.13 (m, 2H), 2.09-2.00 (m, 1H), 1.75-1.66 (m, 1H); LCMS: 542 [M+H].