反应详情

A solution of 2-(6-methyl-pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-3-carboxylic acid ethyl ester (1.6 g, 5.9 mmol) and 2 N sodium hydroxide (6 mL, 29 mmol) in absolute ethanol (50 mL) is refluxed for 5 h. The mixture is cooled to room temperature and concentrated in vacuo. The residue is suspended in water and acidified to pH 5 with 1 N hydrochloric acid. The aqueous solution is extracted three times with dichloromethane. The organic extracts are combined, dried (sodium sulfate), filtered, and concentrated in vacuo to yield the title compound, 1.4 g (97%), as a white solid.

1. concentrationconcentrated in vacuo
2. extractionThe aqueous solution is extracted three times with dichloromethane
3. dry with materialdried (sodium sulfate)
4. filtrationfiltered
5. concentrationconcentrated in vacuo