4-(3-Fluoro-benzyloxy)-2-nitro-benzoic acid (3-fluoro-benzyl) ester and 4-(3-fluoro-benzyloxy)-2-nitro-benzoic acid methyl ester: A mixture of 4-fluoro-2-nitro-benzoic acid methyl ester (9.2 g, 46.3 mmol), 3-fluorobenzyl alcohol (16.7 g, 132.4 mmol) and potassium carbonate (12.8 g, 92.6 mmol) in DMF (210 mL) was heated at 65° C. for 48 h. After cooling to rt, the mixture was poured into water (400 mL), and extracted with diethyl ether (3×100 mL). The combined extracts were washed with brine (100 mL) dried and evaporated. Purification by chromatography on silica gel eluting with ethyl acetate:hexane (1:1) afforded the title compound (14.0 g, 76%) as a light yellow liquid.
