A suspension of sodium hydride (60% dispersion in oil) (2.12 g, 52.9 mmol) in toluene (65 mL) at reflux under N2 was added over 55 mins a solution of Intermediate 153a (15.93 g, assumed 37.8 mmol) and acetonitrile (2.87 mL, 54.9 mmol) in toluene (31 mL). The mixture was heated at reflux for 67 h. The cooled reaction mixture was slowly acidified to pH 5 with aqueous 1N HCl and extracted with EtOAc. The aqueous layer was extracted with EtOAc (×2) and the combined organic phase was washed with brine, dried (Na2SO4) and concentrated in vacuo. The residue was purified by FCC, using 0-50% ether in pentane, to give the title compound (3.52 g, 25%) as a yellow oil. LCMS (Method 3): Rt 4.94 min, m/z 402.3 [M+Na+].
