反应详情

温度

50 °C

50 g of ethyl 1-methyl-3-trifluoromethyl-4-pyrazolecarboxylate were initially charged with 177 g of toluene and 54 g of 25% sodium hydroxide solution and heated to reflux for 15 hours. The cloudy reaction mixture was cooled to 50° C. and admixed with 69 g of water. The aqueous phase was adjusted to pH 1-2 at 30° C. by adding 83 g of 15% hydrochloric acid, and the product precipitated out of solution. The suspension was stirred for a further 30 minutes at room temperature and for 30 minutes at 0° C., and the crude product was then isolated and washed 3 times with 60 g each time of cold (<10° C.) water. After drying at room temperature and under reduced pressure, 43 g of 1-methyl-3-trifluoromethyl-4-pyrazolecarboxylic acid were obtained. This corresponds to a yield of 98% of theory.

1. temperatureheated
2. temperatureto reflux for 15 hours
3. customThe cloudy reaction mixture
4. customwas adjusted to pH 1-2 at 30° C.
5. customthe product precipitated out of solution
6. customthe crude product was then isolated
7. washwashed 3 times with 60 g each time of cold (<10° C.) water
8. customAfter drying at room temperature and under reduced pressure