Methyl iodide → Methyl 2-methyl-2H-indazole-3-carboxylate

Temperatur

0 °C

Methyl indazole-3-carboxylate (3.71 g, 21.1 mmol) was dissolved in DMF (40 ml). To the resulting solution was added sodium hydride (60% in oil, 1.01 g, 25.3 mmol) in portions under stirring at 0° C. The reaction mixture was stirred at the same temperature for 30 minutes. Methyl iodide (1.57 ml, 25.3 mmol) was added to the mixture. The resulting mixture was stirred at the same temperature for 30 minutes. A saturated aqueous solution of ammonium chloride was added and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and distilled under reduced pressure to remove the solvent. The residue was purified by chromatography on a silica gel column, whereby from n-hexane-ethyl acetate (3:1, v/v) eluate fractions, methyl 2-methylindazole-3-carboxylate (1.62 g, 26%) was obtained as a pale yellow solid.

1. stirringThe reaction mixture was stirred at the same temperature for 30 minutes
2. stirringThe resulting mixture was stirred at the same temperature for 30 minutes
3. extractionthe mixture was extracted with ethyl acetate
4. washThe extract was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. distillationdistilled under reduced pressure
7. customto remove the solvent
8. customThe residue was purified by chromatography on a silica gel column, whereby from n-hexane-ethyl acetate (3:1

ORD-Eintrag

ord-f95a75addd494d208704cd6c559d5320

Quelldatensatz

uspto-grants-2007_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07157487B2