A solution of the product of Step 5 (1.2 g, 5.4 mmol ) and the product of Step 6 (2.2 g, 6.4 mmol ) in 1,2-dimethoxyethane (40 ml) and water (20 ml) was treated with potassium carbonate (6.0 g, 43.2 mmol), palladium acetate (0.06 g, 0.27 mmol) and triphenylphosphine (0. 14 g, 0.54 mmol) and heated under reflux for 1.5 hours. After cooling to room temperature, the reaction mixture was poured into water, extracted into ethyl acetate, dried (MgSO4) and concentrated in vacuo. The residue was chromatographed on silica gel eluting with ethyl acetate to afford the title compound (1.0 g, 61%); MS(ES+) m/e 305 [M+H]+.
