General procedure for the synthesis of (2-amino-5-nitrophenyl)methanol from 2-amino-5-nitrobenzoic acid: firstly, compound 24a was prepared from compound 23b according to the literature methodology. after completion of the reaction, the target product 29b was obtained by conventional post-treatment in 92% yield and the product was a butter-like solid. The product was identified by infrared spectroscopy (IR) and the main absorption peaks were located at 3365, 2918, 1612, 1528, 1345, 1239, 1051, 755 cm-1. Nuclear magnetic resonance hydrogen spectroscopy (1H NMR, 400 MHz, CDCl3) showed δ : 1.27-1.35 (1H, m), 2.11 (1H, dt, J = 5.3, 12.8 Hz), 2.25 (1H, dt, J = 2.8, 12.0 Hz), 2.36-2.48 (1H, m), 2.43 (3H, s), 2.90-3.00 (2H, m), 2.96 (1H, d, J = 18.0 Hz), 3.10 (1H, d, J = 18.0 Hz), 3.27 (1H, d, J = 7.61 (1H, dd, J = 2.0, 9.6 Hz), 7.67 (1H, s), 8.29 (1H, d, J = 2.0 Hz), two protons (OH) were not observed. The nuclear magnetic resonance carbon spectrum (13C NMR, 100 MHz, CDCl3) showed δ: 23.9, 35.8, 36.1, 39.1, 40.4, 42.9, 45.3, 61.4, 69.2, 112.6, 115.0, 121.7, 123.3, 125.6, 127.0, 128.3, 129.2, 131.0, 137.2, 140.3, 144.4, 147.0, 155.2, 162.0. High-resolution mass spectrometry (HRMS, ESI) analysis showed calculated value of C24H24N3O4 [M + H]+: 418.1767, measured value: 418.1748.
