A solution of (2-bromo-4-fluoro-phenoxy)-acetic acid (220 mg, 0.91 mmol) and thiophene-2-carboxylic acid N′-isopropyl-hydrazide (200 mg, 1.09 mmol) in DMF (5 ml) was treated with diisopropylethyl amine (0.40 mL, 2.28 mmol) and PyBroP (636 mg, 1.37 mmol) at room temperature overnight. The reaction mixture was partitioned between 1N HCl and ethyl acetate. The organic layer was washed with brine, then dried over sodium sulfate, filtered and concentrated. The crude was absorbed on silica and purified on a silica gel column with a 10-50% ethyl acetate/hexanes gradient to afford the product as a solid (263 mg, 70%).
