反应详情

A solution of 16.8 g of 3-(1-acetyl-4-piperidinyl)-6-fluoro-1-methyl-1H-indazole and 100 ml of 6N hydrochloric acid was heated under reflux for 4 hrs. The solution was cooled in an ice bath, 50% aqueous sodium hydroxide was added, dropwise, with stirring and the mixture was extracted with ethyl acetate. Concentration of the organic extract gave an oil. The oil was dissolved in ethyl acetate and a saturated solution of ethyl acetate-hydrogen chloride was added. The salt was recrystallized twice from trichloromethane-ether and then from isopropanol (charcoal) to yield 3.0 g (21%) of product, mp 256°-258° C.

1. temperatureunder reflux for 4 hrs
2. temperatureThe solution was cooled in an ice bath
3. extractionthe mixture was extracted with ethyl acetate
4. extractionConcentration of the organic extract
5. customgave an oil
6. customThe salt was recrystallized twice from trichloromethane-ether