To a solution of 2-chloro-3-(1-cyanocyclopropyl)benzoic acid (4.42 g, 20 mmol) produced in Example C62(ii) in oxalyl chloride (10 mL) was added N,N-dimethylformamide (100 μL), and the mixture was stirred at room temperature for 1 hr, and concentrated to dryness under reduced pressure. This was dissolved in tetrahydrofuran (10 mL), and the solution was added dropwise with vigorous stirring to a two-layer mixture of a solution of 3-amino-4-fluorophenol (2.54 g, 20 mmol) in tetrahydrofuran (10 mL) and a solution (10 mL) of sodium hydrogen carbonate (2.70 g, 30 mmol) in water under ice-cooling. The reaction mixture was stirred at room temperature for 1 hr, and poured into water (200 mL), and the mixture was extracted with ethyl acetate (100 mL×2). The ethyl acetate layers were combined, and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate/hexane=0/100→50/50) to give the title compound (6.50 g, 98%) as white crystals.
