To a solution of Intermediate A (50 mg, 0.309 mmol) in DMF (2 mL) was added NaH (60% in oil, 33 mg, 0.80 mmol) and the mixture stirred at RT for 20 min, before Intermediate 28b (110 mg, 0.280 mmol) was added. This mixture was heated at 60° C. in the microwave for 1.25 h. The reaction mixture was applied to an SCX-2 cartridge (25 g) and washed with MeOH. The product was eluted with 2M NH3 in MeOH; concentration in vacuo gave a residue. FCC, using 0-7% [2M NH3 in MeOH] in DCM gave the title compound as a viscous yellow oil (42 mg, 28%). LCMS (Method 4): Rt 2.55 min, m/z 536 [MH+].
