A degassed solution of (R)-6-bromo-4-(1-cyclopropylethylamino) pyrrolo[1,2-b]pyridazine-3-carboxamide (Intermediate 4, 20 mg, 0.062 mmol), phenylboronic acid (22.64 mg, 0.186 mmol), potassium carbonate (0.077 mL, 0.155 mmol, 2M) and palladium tetrakis(triphenylphosphine) (4.29 mg, 3.71 μmol) in DME (1 mL) was heated to 90° C. for 1 hr. The reaction mixture was concentrated and redissolved in 1 mL of MeOH, and purified by reverse-phase preparative HPLC (condition C) to yield the title compound (9.8 mg, 48%). HPLC (condition I): retention time=2.49 min. LC/MS (M+H)+=321.1. 1H NMR (500 MHz, MeOD) δ ppm 8.04 (1 H, s), 7.82 (1 H, d, J=1.7 Hz), 7.61 (1 H, d, J=1.1 Hz), 7.59 (1 H, d, J=0.8 Hz), 7.56 (1 H, s), 7.37 (2 H, t, J=7.8 Hz), 7.21-7.26 (1 H, m), 4.05 (1 H, quin, J=6.4 Hz), 1.44 (3 H, d, J=6.4 Hz), 1.08-1.17 (1 H, m), 0.52-0.62 (2 H, m), 0.35-0.41 (2 H, m).
