To a suspension of 2-(4-fluorophenyl)-3-(4-(3-(E)-methoxy-3-oxoprop-1-en-1-yl)phenyl)acrylic acid (2 g, 6.1 mmol, prepared according to the procedure described in Example 1, step-II) in THF (10 mL), triethylamine was added (0.85 mL, 6.67 mmol) under constant stirring at 5° C. To this solution, methyl chloroformate (0.53 mL, 6.67 mmol) was added dropwise over a period of 30 minutes at 5° C. and stirred at the same temperature for 30 minutes. To this reaction mixture, sodium borohydride (0.9 g, 24.5 mmol) was added at one portion and methanol (5 mL) was added dropwise under stirring and the reaction mixture was stirred at 30° C. for 2 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate (300 mL) and washed successively with water (2×100 mL) and brine (1×100 mL). The organic layer was dried over anhydrous Na2SO4 and concentrated to afford the crude compound, which was purified by column chromatography using 12% ethylacetate/hexanes as the eluent to afford a pure compound as a white solid (1.5 g, 79% yield).
