Benzylamine → N-benzyl-4-(2-(tert-butoxy)pyridin-4-yl)-8-phenylphthalazin-1-amine

Benzylamine (5.00 mL, 45.8 mmol) was added to 1-(2-(tert-butoxy)pyridin-4-yl)-4-chloro-5-phenylphthalazine (0.200 g, 0.513 mmol) and heated in a sealed tube at 100° C. for 12 h. The reaction mixture was diluted with dichloromethane (100 mL) and washed with water (50 mL) followed by brine (25 mL). The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The resulting residue was purified by flash chromatography using Combiflash Isco (REDISEP®, basic Al2O3, 80 g, 0-70% ethyl acetate/petroleum ether) to remove excess benzyl amine. The resulting residue was then purified by preparative HPLC (Condition 33 as described in general methods) to afford N-benzyl-4-(2-(tert-butoxy)pyridin-4-yl)-8-phenylphthalazin-1-amine (0.120 g, 50.8%) as a white solid. LCMS (Condition 34): retention time 2.67 min, [M+1]=461.2. HPLC (Condition 35): retention time=21.80 min, purity 99.30%. 1H NMR (400 MHz, DMSO-d6) δ 1.63 (s, 9 H), 4.50 (d, J=5.2 Hz, 2 H), 5.07 (t, J=5.2 Hz, 1 H), 6.90 (dd, J=0.4 Hz, J=0.8 Hz, 1 H), 7.00-7.03 (m, 2 H), 7.17 (dd, J=1.6 Hz, J=5.2 Hz, 1 H), 7.22-7.28 (m, 3 H), 7.42-7.50 (m, 5 H), 7.67 (dd, J=1.2 Hz, J=6.8 Hz, 1 H), 7.85-7.93 (m, 2 H), 8.31 (dd, J=0.4 Hz, J=5.2 Hz, 1 H).