To a solution of ethyl 3,5-dibromothiophene-2-carboxylate (Prepared according to procedure reported in J. Chem. Soc. Perkin Trans-1: Organic and Bioorganic Chemistry (1972-1999), 1973, p 1766-1770), 2.0 g (6.36 mmol) in a mixture of toluene:water (35:2 ml) was added (4-chlorophenyl)boronic acid [0.99 g, 6.36 mmol] and potassium carbonate (1.76 g, 12.73 mmol) at 25° C. Nitrogen gas was bubbled through reaction mixture for 15 minutes. To the reaction mixture was then added tetrakis(triphenylphosphine)palladium(0) (0.37 g, 0.31 mmol) under nitrogen atmosphere and the reaction mixture was heated at about 95 to about 100° C. for 3 hr under stirring. The progress of the reaction was monitored by TLC. The reaction mixture was then cooled to 25° C. and filtered through celite and the celite cake was washed with ethyl acetate (50 ml). The filtrate so obtained was concentrated under reduced pressure to obtain a crude product, which was then purified by flash column chromatography using and 6% ethyl acetate in hexanes as an eluent to obtain the title compound (1.5 g, 68.18%).
