Hydrogen Bromide → HCID 178515474, compound

Participants

Reaction Steps

4.85 g 1-(3,4-dichlorobenzyl)-5-methoxy-1H-indazole-3-ol are heated in 30 ml acetic acid and 30 ml 50% hydrobromic acid for 4 hours under gentle reflux. After cooling, the mixture is stirred into 250 ml water, rendered alkaline with concentrated sodium hydroxide solution and extracted twice with 80 ml tert-butyl methyl ether. The aqueous phase is acidified with sulfuric acid and extracted by shaking three times with 200 ml tert-butyl methyl ether. The combined ether phases are dried over sodium sulfate and distilled to dryness under vacuum. The residue is washed with a small amount of tert-butyl methyl ether and dried.

Provenance & Evidence