To a solution of the title compound of Step C (700 mg, 3.7 mmol) in dimethylformamide (10 mL) was added sodium hydride as a 60% oil dispersion (160 mg) followed by the title compound of Step B. The mixture was stirred at room temperature for 4 h and then was diluted with ethyl acetate. The solution was washed with water and then saturated sodium chloride solution. The organic phase was dried (MgSO4) and concentrated under reduced pressure to afford an oil. Chromatography of this oil on silica gel with 20-30% ethyl acetate in hexanes afforded 1.0 g of the title compound of Step D, a compound of the invention, as an oil which solidified on standing. 1H NMR (CDCl3): δ 7.68 (m,7H), 5.2 (m,2H), 3.47 (s,3H), 2.75 (m,4H), 2.15 (s,3H), 1.78 (m,4H). This material was used in the preparation of Example 4 without further characterization.
