2,3-Diaminobenzoic acid is synthesised using 3-nitroanthranilic acid as a raw material by chemical reaction. The specific synthesis steps are as follows:
2-amino-3-nitrobenzoic acid (9.36 g, 51.4 mmol) was dissolved in MeOH (100 mL) and there was added 10% Pd/C (2.0g). The reaction was stirred under H2-atmosphere (ambient pressure) until absorption ceased. The reaction was filtered through a pad of Celite and the filtrate was evaporated under reduced pressure. The product was purified by flash chromatography (CH2Cl2/MeOH 5:1) and the collected fractions were evaporated to give 2,3-Diaminobenzoic acid (5.40 g, 69%) as a dark brown solid. mp. 199 °C dec. (Litt4. 201 °C dec.). 1H NMR (300 MHz, DMSO-d6) δ 7.09 (dd, J = 8.0, 1.5 Hz, 1H), 6.67 (dd, J = 7.4, 1.5 Hz, 1H), 6.34 (dd, J = 8.0, 7.4 Hz, 2H), 6.32 (br s, 4H). 13C NMR (75 MHz, DMSO-d6) δ 170.5, 139.6, 135.6, 119.4, 117.0, 114.9, 110.3.
