Reaction Steps
Ar was bubbled through a solution of Intermediate 57c (93.0 mg, 0.135 mmol) and 1,3-dimethyl barbituric acid (63.0 mg, 0.404 mmol) in DCM (5 mL) at RT under Ar for 30 min, then Pd(PPh3)4 (15.6 mg, 0.0135 mmol) was added and the orange solution was stirred at RT for 1 h, and then at reflux for 17 h. The suspension was concentrated in vacuo, the residue redissolved in DCE (10 mL) and Ar bubbled through the mixture for 30 min. Pd(PPh3)4 (15.6 mg, 0.0135 mmol) was added and the opaque orange-red solution stirred at 75° C. under Ar for 2 h. The cooled solution was concentrated in vacuo to 3 mL volume, then applied to an SCX-2 cartridge (5 g) and washed with MeOH (25 mL). The product was eluted with 2M NH3 in MeOH (20 mL); concentration in vacuo left an orange solid. FCC, using 5-15% MeOH in DCM, gave a pale orange solid (46.0 mg). Further purification by HPLC (XBridge C18 column, 20-80% MeCN in H2O, 0.1% NH4OH) gave the title compound as a white powder after freeze-drying (27.1 mg, 31%). LCMS (Method 5): Rt 3.59 min, m/z 651 [MH+]. 1H NMR (400 MHz, d6-DMSO): 1.23 (9H, s), 1.56-1.67 (2H, m), 1.76-1.92 (4H, m), 1.95-2.11 (2H, m), 2.91-2.97 (2H, m), 3.31-3.35 (2H, m), 3.64-3.71 (1H, m), 4.51 (2H, d, J 4.2), 4.70 (1H, d, J 3.9), 4.77 (1H, m), 5.25 (1H, t, J 5.3), 5.50 (1H, t, J 4.4), 6.29 (1H, s), 7.05 (1H, d, J 8.5), 7.10 (1H, dd, J 9.9, 2.1), 7.21-7.25 (2H, m), 7.28-7.34 (2H, m), 7.39 (2H, d, J 9.1), 7.40 (2H, d, J 9.1), 7.56 (1H, dd, J 9.9, 0.8), 7.61 (1H, dd, J 2.1, 0.9), 8.04 (1H, s).
