To a mixture of 3-amino-2-isopropylquinazolin-4(3H)-one (Aldrich, 80 mg, 0.4 mmol) and Example 22C (55 mg, 0.4 mmol) in tetrahydrofuran (5 mL) was added a solution of 1-propanephosphonic acid cyclic anhydride (Aldrich, 50% w/w in ethyl acetate (0.7 mL, 1.2 mmol) followed by triethylamine (0.16 mL, 1.2 mmol). The reaction was stirred at 80° C. overnight. The reaction was quenched with 1M NaHCO3 (10 mL). The aqueous layer was extracted with ethyl acetate (2×20 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography (SiO2, 0-50% of ethyl acetate in hexanes) to obtain 65 mg of the title compound. 1H NMR (400 MHz, CDCl3) δ ppm 1.10 (m, 2H), 1.21-1.29 (m, 1H), 1.31 (d, J=6.7 Hz, 3H), 1.36 (d, J=6.7 Hz, 3H), 1.57-1.78 (m, 2H), 1.94-2.07 (m, 1H), 2.42-2.68 (m, 5H), 3.12-3.27 (m, 1H), 7.38-7.50 (m, 1H), 7.65-7.81 (m, 3H), 8.21 (dd, J=8.1, 1.0 Hz, 1H); MS (ESI+) m/z 326 (M+H)+. Elemental Analysis: Calculated for C19H23N3O2: C: C, 70.13; H, 7.12; N, 12.91. Found: C, 70.32; H, 7.10; N, 12.85.
