反应详情

温度

-7 °C

Under cooling, (1-benzyl-3,5-dimethyl-1H-pyrazol-4-yl)-acetic acid methyl ester (intermediate 1.1.1, 3.10 g, 12.0 mmol) was dissolved in conc. H2SO4 (7 mL). The mixture was cooled to −7° C. and HNO3 (65%, 0.77 mL) was added dropwise under stirring, keeping the temperature below 0° C. The reaction mixture was allowed to come to room temperature and stirred for 20 min at room temperature. The reaction mixture was poured into ice water, extracted with dichloromethane and the organic layer was concentrated under reduced pressure. The resulting product is a mixture of regioisomers, with the 4-nitro isomer as the main product.

1. temperatureUnder cooling
2. customthe temperature below 0° C
3. customto come to room temperature
4. stirringstirred for 20 min at room temperature
5. extractionextracted with dichloromethane
6. concentrationthe organic layer was concentrated under reduced pressure
7. additiona mixture of regioisomers