反应详情

Methyl-1-methylindazole-3-carboxylate (3.1 g, 0.016 mol) was stirred with a solution of sodium hydroxide (0.78 g, 0.02 mol) in tetrahydrofuran (100 ml) for 2 hours at room temperature, the solution evaporated and the yellow residue were dissolved in water. Acidification with methanesulfonic acid precipitated 1-methylindazole-3-carboxylic acid (2.19 g). A further crop (0.3 g) was obtained by extraction of the aqueous acid solution with a mixture of ether and methylene chloride. Total yield 2.49 g (87%).

1. customthe solution evaporated
2. dissolutionthe yellow residue were dissolved in water
3. customAcidification with methanesulfonic acid precipitated 1-methylindazole-3-carboxylic acid (2.19 g)
4. customA further crop (0.3 g) was obtained by extraction of the aqueous acid solution with a mixture of ether and methylene chloride