5-(4-(4-(6-methylpyridin-3-yloxy)-3-methylphenylamino)quinazolin-6-yl)furan-2-carbaldehyde, 4-methyl-1,4-azaphosphinane 4-oxide hydrogen chloride salt and DIPEA were suspended in dichloromethane (20 mL). Sequentially, acetic acid (3 drops) and sodium triacetoxyborohydride (2 equiv.) were added at room temperature. The mixture was stirred at room temperature until the starting material disappeared. The reaction was quenched with 2N NaOH aqueous solution and extracted with dichloromethane. The combined organic layer and extracts were dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by flash chromatography, eluting with 20% methanol in dichloromethane to give the desired product as yellow crystalline solid. LCMS ESI(+) m/z: 554 (M+1). 1H NMR (300 MHz, CDCl3) δ 8.71 (s, 1H), 8.47 (s, 1H), 8.18 (d, 1H), 8.12 (s, 1H), 7.77 (d, 1H), 7.69 (m, 1H), 7.60 (d, 1H), 7.28 (m, 2H), 6.99 (m, 2H), 6.51 (d, 1H), 3.83 (s, 2H), 3.73 (m, 2H), 3.24 (m, 2H), 2.95 (m, 2H), 2.51 (s, 3H), 2.27 (s, 3H), 2.04 (m, 2H), 1.58 (m, 3H).
