Synthesis
The general procedure for the synthesis of 3-amino-2-methylbenzoic acid from 2-methyl-3-nitrobenzoic acid was as follows: 2-methyl-3-nitrobenzoic acid (2 g, 12.12 mmol) was dissolved in ethyl acetate in a two-necked round-bottomed flask and 5% Pd-C catalyst (0.10 g) was added. The reaction mixture was stirred for 15 h under hydrogen atmosphere. After completion of the reaction, the solvent was removed by distillation under reduced pressure to give the crude product. The crude product was purified by column chromatography (silica gel 60-120 mesh, with dichloromethane and ethanol (v/v, 99.5:0.5) as eluents) to give a white solid product with a melting point of 181°C. IR (νmax, cm-1): 3244 (νN-H), 1724 (νC=O, acid), 1284 (νC-N, aromatic amine). Elemental analysis (C8H9NO2) Calculated values: C, 63.56%; H, 6.00%; N, 9.27%. Measured values: C, 63.13%; H, 5.87%; N, 8.99%.
References
[1] Tetrahedron Letters, 2000, vol. 41, # 11, p. 1741 - 1745
[2] Journal of Molecular Structure, 2013, vol. 1049, p. 78 - 89
[3] Bulletin de la Societe Scientifique de Bretagne, 1956, vol. 31, p. Sonderheft S.9,41
[4] Bulletin de la Societe Chimique de France, 1973, p. 3427 - 3432
[5] Tetrahedron Letters, 1998, vol. 39, # 47, p. 8589 - 8592
