反应详情

温度

20 °C

3-Methyl-1H-indazole (6.157 g, 44.6 mmol) in CH2Cl2 (100 mL) was treated with acetic anhydride (22.75 g, 223 mmol), triethylamine (22.5 g, 228 mmol) and DMAP (0.54 g, 4.5 mmol). The mixture was stirred 1 h at 20° C., poured into water (100 mL) and extracted with CH2Cl2 (2×100 mL). The extracts were dried (Na2SO4), concentrated and the residue recrystallised from hexane to give the title compound (4.12 g, 66%) as a white crystalline solid; mp 70°-71° C. (from hexane); 1H NMR (360 MHz, CDCl3) δ 8.41 (d, J=8.4 Hz, 1H, indazole), 7.64 (d, J=8.4 Hz, 1H, indazole), 7.54 (t, J=8.4 Hz, 1H, indazole), 7.35 (t, J=8.4 Hz, 1H, indazole), 2.75 (s, 3H, Ac), 2.58 (s, 3H, Me); MS (CI+) m/e 175 (M+H+); Anal. calcd for C10H10N2O: C, 68.95; H, 5.97; N, 16.08. Found: C, 68.80; H, 5.58; N, 16.18.

1. extractionextracted with CH2Cl2 (2×100 mL)
2. dry with materialThe extracts were dried (Na2SO4)
3. concentrationconcentrated
4. customthe residue recrystallised from hexane