反应详情

温度

80 °C

Copper sulfate pentahydrate (0.08 g; 0.33 mmol; 0.06 eq.) was added to a solution of tert-butyl-3-ethynyl-5-methyl-1H-indazole-1-carboxylate (1.55 g; 6.03 mmol; 1.0 eq.), methyl 4-azidobenzoate (prepared as described in JOC (2006), 71(15), 5822-5825; 1.20 g; 6.77 mmol; 1.1 eq.) and D-(−)-isoascorbic acid sodium salt (0.24 g; 1.22 mmol; 0.20 eq.) in DMF (15 mL) and water (0.50 mL). The reaction suspension was heated in MW at 80° C. for 45 min then poured into HCl (0.1 N solution) and extracted with EtOAc. Combined organic phases were washed with brine, dried over magnesium sulfate, filtered and concentrated. The crude was purified by flash chromatography on silica (n-heptane/EtOAc, gradient from 90:10 to 60:40) to give the title compound as a yellow solid. 1H NMR (300 MHz, DMSO) δ 9.66 (s, 1H), 8.35-8.25 (m, 3H), 8.20 (d, J=8.8 Hz, 2H), 8.05 (d, J=8.7 Hz, 1H), 7.54 (dd, J=1.5, 8.7 Hz, 1H), 3.91 (s, 3H), 2.53 (s, 3H), 1.69 (s, 9H). HPLC (Condition A): Rt 5.07 min (purity 96.8%). MS (ESI+): 434.4.

1. extractionextracted with EtOAc
2. washCombined organic phases were washed with brine
3. dry with materialdried over magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude was purified by flash chromatography on silica (n-heptane/EtOAc, gradient from 90:10 to 60:40)