Reaktion #1009764

Reaktionsgleichung

Water

6-bromo-4-chloro-1H-indazole

cesium hydroxide monohydrate

methyl iodide

→

6-Bromo-4-chloro-1-methyl-1H-indazole

Ausbeute 62.0%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe aqueous layer was extracted with EtOAc
2. 2
   EinengenThe organic layer was concentrated
3. 3
   Sonstigethe crude reside was purified by silica gel column chromatography (EtOAc/Heptane 0 to 100% gradient as eluent)

Vorschrift

To a mixture of 6-bromo-4-chloro-1H-indazole (4.0 g, 17.4 mmol), cesium hydroxide monohydrate (23.3 g, 139 mmol), tetrabutylammonium hydrogensulfate (1.36 g, 3.99 mmol) in anhydrous THF (80 mL) was added a solution of methyl iodide (9.86 g, 69.4 mmol) in THF (10 mL) dropwise at r.t. The reaction mixture was stirred for 15 min at r.t. Water was added to the reaction mixture, and the aqueous layer was extracted with EtOAc. The organic layer was concentrated, and the crude reside was purified by silica gel column chromatography (EtOAc/Heptane 0 to 100% gradient as eluent) to afford 6-Bromo-4-chloro-1-methyl-1H-indazole (2.65 g, 62%). 1H NMR (600 MHz, methanol-d4) δ 4.05 (s, 3H), 7.32 (d, 1H), 7.79 (s, 1H), 8.03 (s, 1H).

Quelle