A mixture of compound 202 (3.00 g, 7.73 mmol) and 4-methoxybenzylamine (10.2 mL, 77.3 mmol) in dry DMSO (18 mL) was stirred under a nitrogen atmosphere at 68-70° C. (bath temperature) for 165 h. The solution was then cooled and petroleum ether (200 mL) was added. It was stirred at room temperature for 15 min. The layers were allowed to separate and the petroleum ether layer was decanted. This procedure was repeated with more petroleum ether (200 ml). Water (200 mL) was added and the mixture was stirred at room temperature for 45 min. The oil was deposited. Thus, the product was extracted into ethyl acetate; dried (MgSO4) and solvent removed to give a brown oil. It was purified by a silica column (EtOAc/petroleum ether: gradient from 30% to pure EtOAc) to give pure N4-(1-(3-fluorobenzyl)-1H-indazol-5-yl)-N6-(4-methoxybenzyl)pyrido[3,4-d]pyrimidine-4,6-diamine (211) (2.38 g, 61%) as a yellow/orange solid, mp 196-198° C.; 1H NMR δ [(CD3)2SO] 9.75 (s, 1H), 8.72 (s, 1H), 8.29 (s, 1H), 8.22 (poorly resolved d, J=1.3 Hz, 1H), 8.15 (d, J=0.7 Hz, 1H), 7.73 (br d, J=9.0 Hz, 1H), 7.68 (dd, J=9.0, 1.8 Hz, 1H), 7.40-7.31 (m, 3H), 7.24-7.17 (m, 2H), 7.13-7.01 (m, 3H), 6.92-6.84 (m, 2H), 5.70 (s, 2H) 4.49 (d, J=6.3 Hz, 2H), 3.71 (s, 3H). Anal. Calcd for C29H24FN7O.1.5H2O: C, 65.40; H, 5.11; N, 18.41%. Found C, 65.45; H, 5.07; N, 18.58%.
