反应详情

温度

90 °C

3-Ethynyl-5-methyl-1H-indazole (1.0 g; 6.4 mmol; 1.0 eq.) and 4-azidobenzaldehyde (prepared as described in Chem. Med. Chem. (2009), 4(7), 1182-1188; 1.30 g; 7.04 mmol; 1.1 eq.) were dissolved in 1,4-dioxane (15 mL). D-(−)-isoascorbic acid sodium salt (127 mg; 0.64 mmol; 0.10 eq.) followed by a solution of copper sulfate pentahydrate (32 mg; 0.13 mmol; 0.02 eq.) in water (1.5 mL) were added and the reaction mixture was stirred at 90° C. for 3.5 hours. To complete the reaction more D-(−)-isoascorbic acid sodium salt (127 mg; 0.64 mmol; 0.10 eq.) and copper sulfate pentahydrate (32 mg; 0.13 mmol; 0.02 eq.) were added again and the reaction mixture was heated at 10° C. for 8 h. 1,4-dioxane was removed under reduced pressure an the residue was sonicated in a mixture of EtOAc and water (1:1). The resulting solid was filtered and dried to afford the title compound as a beige solid (1.94 g, 100%). 1H NMR (300 MHz, DMSO-d6) δ: 13.29 (brs, 1H), 10.11 (s, 1H), 9.46 (s, 1H), 8.34 (d, J=8.6 Hz, 2H), 8.18 (d, J=8.6 Hz, 2H), 8.14 (m, 1H), 7.51 (d, J=8.4 Hz, 1H), 7.28 (dd, J=8.4 Hz, 1.4 Hz, 1H), 2.49 (s, 3H).

1. additionwere added
2. additionwere added again
3. temperaturethe reaction mixture was heated at 10° C. for 8 h
4. custom1,4-dioxane was removed under reduced pressure an the residue
5. customwas sonicated in a mixture of EtOAc and water (1:1)
6. filtrationThe resulting solid was filtered
7. customdried