Réaction #1144316

Équation de réaction

NaHCO3

5-bromo-7-fluoro-1H-indazole

3,4-dihydro-2H-pyran

p-TsOH

→

5-bromo-7-fluoro-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   AutreThe organic layer was separated
2. 2
   Séchagedried over Na2SO4
3. 3
   Concentrationconcentrated in vacuo
4. 4
   AutreThe residue was purified by column chromatography on silica gel (0˜10% EtOAc in petroleum ether)

Mode opératoire

To a mixture of 5-bromo-7-fluoro-1H-indazole (9.3 g, 43.26 mmol) and 3,4-dihydro-2H-pyran (4.36 g, 51.9 mmol) in dry dichloromethane (100 mL), was added p-TsOH (424 mg, 2.16 mmol) at room temperature. The resulting mixture was stirred overnight. Work-up: saturated aqueous NaHCO3 (30 mL) was slowly added to the reaction mixture. The organic layer was separated, dried over Na2SO4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (0˜10% EtOAc in petroleum ether) to give 5-bromo-7-fluoro-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole as a light yellow solid. (7.8 g). 1H NMR (300 MHz, CDCl3): δ 7.98 (s, 1H), 7.64 (s, 1H), 7.22 (dd, 1H), 5.84 (dd, 1H), 4.07-4.02 (m, 1H), 3.78-3.71 (m, 1H), 2.62-2.53 (m, 1H), 2.16-2.07 (m, 2H), 1.79-1.71 (m, 2H), 1.63-1.33 (m, 1H).

Source