2-Methyl-3-nitrobenzoic acid → N-methoxy-N,2-dimethyl-3-nitrobenzamide

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Reaction Steps

Carbonyl diimidazole (9.8 g, 60.7 mmol) was added to a solution of 2-methyl-3-nitrobenzoic acid (10 g, 55 mmol) in CH2Cl2 (200 mL) at 0° C. and stirred for 30 min. The reaction mixture was warmed to room temperature, stirred for 2 h, and cooled to 0 C. N,O-dimethylhydroxylamine hydrochloride was added to the reaction mixture at 0 C, stirred for 30 min., and heated to 45 C for 1 h. The reaction mixture was cooled to room temperature, stirred for 12 h, and quenched with aqueous K2CO3 (10%, 200 mL). The reaction mixture was extracted with CH2Cl2 (3×200 mL) and the combined extracts were dried (MgSO4), filtered, and concentrated in vacuo. Purification by flash column chromatography (silica, 6:4 hexanes:EtOAc) provided the title compound a white solid (2.6 g, 21%). MS: 225 (MH+); HPLC Rf: 3.96 min. (HPLC method 4); HPLC purity: 98%.

Provenance & Evidence