Dimethylformamide → N-Formyl-N-methylamino benzoic acid

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Reaction Steps

3-Formylamino benzoic acid (2.28 g, 13.8 mmol) was taken up in DMF (25 ml) and added dropwise to a suspension of sodium hydride (1.05 g, 80% disp. in oil) in DMF (15 ml) at 0° C. The mixture was allowed to warm to r.t. over 1 h and then iodomethane (0.95 ml) added. A second portion of iodomethane (0.95 ml) was added after 1 h and the mixture stirred at r.t. overnight. The solvent was removed by evaporation and the product partitioned between ethyl acetate and 1M HCl. The organic layer was washed with brine, then filtered (Whatman® 1 PS phase separator) and evaporated. The residue was chromatographed on silica (eluant 60% ethyl acetate in hexanes) to provide the title compound as a colourless solid (2.30 g, 86%). A portion of the ester (900 mg, 4.66 mmol) was taken up in dioxan/water (2/1, v/v, 30 ml) and treated with LiOH.H2O (378 mg, 9 mmol) at r.t. with stirring overnight. The mixture was acidified with 1M HCl and extracted twice with EtOAc. The combined extracts were washed with brine, filtered (Whatman® 1 PS phase separator) and evaporated. The acid (420 mg, 50%) was used in the next step without further purification.

Provenance & Evidence