Ethyl Acetate → 2,3-Diaminobenzoic acid methyl ester

Participants

Reaction Steps

2-Amino-3-nitro-benzoic acid methyl ester (50.7 g, 258.7 mmol) was suspended in methanol (441 ml) and ethyl acetate (441 ml) with palladium-on-active charcoal 10% (1.93 g, 1.81 mmol). The suspension was hydrogenated at room temperature under an H2 pressure of 2.5 bar. When the reaction was complete, the suspension was filtered over Celite and the residue was rinsed with ethyl acetate. The filtrate was concentrated to dryness under reduced pressure, the residue was dissolved in ethyl acetate (50 ml) and hexane (50 ml) was added. After addition of starting crystals, a precipitate precipitated out. Hexane (200 ml) was added to the suspension and the precipitate was filtered off, washed with hexane and dried in vacuo. Methyl 2,3-diaminobenzoate (D-01) was obtained (35.8 g, 83%).

Provenance & Evidence