Methyl 3-methoxy-4-nitrobenzoate → Methyl 4-amino-3-methoxybenzoate

Participants

Reaction Steps

A 2-L, Parr high-pressure hydrogenation bottle (glass rated to 80 psi) was charged with Pd/C (10 wt % on Carbon, 5 g), ethyl acetate (800 mL) and 32 (120.5 g, 0.57 mol). The reaction mixture was charged with H2 (30 psi) on a Parr apparatus. Charging H2 was continued carefully several times until the pressure remained steady. This took approximately about 3 h. The reaction was shaken for an additional 0.5 h. After the hydrogenation, the reaction mixture was diluted with ethyl acetate to dissolve some of the precipitated product and directly passed through a short pad of Celite, and washed with ethyl acetate. The solvent was evaporated to yield 4-amino-3-methoxy-benzoic acid methyl ester 33 as a white solid. 1H NMR (400 MHz, CDCl3) δ: 7.55 (dd, 1H), 7.45 (d, 1H), 6.66 (d, 1H), 4.21 (s, 2H), 3.90 (s, 3H), 3.86 (s, 3H). MS (ES) m/z 182.1 (MH)+.

Provenance & Evidence