Reaction Steps
To a stirred solution of 1-[9-(6-hydroxymethyl-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl)-9H-purin-6-yl]-3-phenyl-urea (43 mg, 0.1 mmol) in dry N,N′-dimethylformamide (1 mL) at 23° C. was added potassium tert-butoxide (45 mg, 0.4 mmol). After 30 min, 2-chloronicotinic acid (60 mg, 0.4 mmol) was added to the solution. The resulting mixture was stirred at 23° C. for 15 h and then quenched with water (1 mL), suspended in ethyl acetate (50 mL), washed with brine (3×), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give the crude product. Preparative reverse-phase HPLC was used to obtain the pure compound (15 mg, 27% yield) as a white solid. 1H NMR (300 MHz, DMSO-d6) δ 11.76 (s, 1H), 10.15 (s, 1H), 9.16 (s, 1H), 8.65 (s, 1H), 8.05 (dd, J=8.5 Hz, 3.5 Hz, 1H), 7.94 (dd, J=9.0 Hz, 3.0 Hz, 1H), 7.60 (d, J=2.0 Hz, 1H), 7.57 (d, J=2.0 Hz, 1H), 7.32 (t, J=12.5 Hz, 2H), 7.05 (t, J=12.5 Hz, 1H), 6.96 (dd, J=12.5 Hz, 8.5 Hz, 1H), 6.25 (d, J=6.0 Hz, 1H), 5.80 (t, J=7.5 Hz, 1H), 5.10 (dd, J=9.0 Hz, 2.5 Hz, 1H), 4.67 (m, 1H), 4.53 (dd, J=20.0 Hz, 4.0 Hz, 1H), 4.36 (dd, J=20.0 Hz, 4.0 Hz, 1H), 1.59 (s, 3H), 1.38 (s, 3H). MW calculated for C26H25N7O7 (MH+) 548. found 548 by LCMS.