Synthesis
General procedure for the synthesis of 4-amino-2,3-xylenol from 2,3-dimethyl-4-nitrophenol: A mixture of 2,3-dimethyl-4-nitrophenol (2 g, 1.2 mmol) with 10% Pd/C catalyst (1.83 g) in ethanol (80 mL) was placed under hydrogen atmosphere and reacted with stirring at room temperature for 5 hours. Upon completion of the reaction, the crude reaction mixture was filtered through diatomaceous earth and the filter cake was washed with dichloromethane (DCM). After evaporation to remove the solvent, 4-amino-2,3-xylenol (1.60 g, 97% yield) was obtained as a brown powder. The product was characterized by 1H-NMR (DMSO-d6): δ 1.94 (s, 3H, methyl proton), 2.01 (s, 3H, methyl proton), 4.06 (s, 2H, amino proton), 6.32 (d, 1H, aromatic proton H-6, J = 8.1 Hz), 6.40 (d, 1H, aromatic proton H-5, J = 8.1 Hz), 6.61 (s , 1H, aromatic proton H-2), 8.10 (broad s, 1H, hydroxyl proton).
References
[1] Patent: WO2006/43090, 2006, A1. Location in patent: Page/Page column 176
[2] Journal of Medicinal Chemistry, 2009, vol. 52, # 13, p. 3881 - 3891