反应详情

A mixture of 0.30 g of ethyl 1-(3-chloro-2-pyridinyl)-3-methyl-1H-pyrazole-5-carboxylate, 5 ml of methanol and 5 ml of a 2N aqueous sodium hydroxide solution was heated to reflux for 3 hours. After the reaction mixture was allowed to cool, water was poured and the aqueous layer was washed with methyl t-butyl ether two times. The aqueous layer was adjusted to around pH 3 by an addition of 2N hydrochloric acid, and then extracted with methyl t-butyl ether three times. The combined organic layer was washed with an aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain 0.24 g of 1-(3-chloro-2-pyridinyl)-3-methyl-1H-pyrazole-5-carboxylic acid of the formula:

1. temperaturewas heated
2. temperatureto reflux for 3 hours
3. temperatureto cool
4. washthe aqueous layer was washed with methyl t-butyl ether two times
5. additionThe aqueous layer was adjusted to around pH 3 by an addition of 2N hydrochloric acid
6. extractionextracted with methyl t-butyl ether three times
7. washThe combined organic layer was washed with an aqueous saturated sodium chloride solution
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated under reduced pressure