反应详情

温度

35 °C

Dimethyl 4-benzyloxy-1H-pyrazole-3,5-dicarboxylate (25 g, 86 mmol) was dissolved in N,N-dimethylhydrazine (75 mL) and the stirred mixture heated to reflux under nitrogen atmosphere for 30 hours. The solvent was removed in vacuo to give a white solid. The residue was dissolved in water (200 mL), 1N HCl (75 mL), and ethyl acetate (100 mL). The mixture was stirred and warmed to 35° C. until all the solids had dissolved. The layers were then separated and the aqueous layer was extracted with more ethyl acetate (3×100 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure to give the product as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 13.2 (br s, 1H), 7.3-7.45 (m, 5H), 5.09 (s, 2H), 3.81 (s, 3H); ES MS (M+1)=277.

1. temperaturethe stirred mixture heated
2. temperatureto reflux under nitrogen atmosphere for 30 hours
3. customThe solvent was removed in vacuo
4. customto give a white solid
5. dissolutionhad dissolved
6. customThe layers were then separated
7. extractionthe aqueous layer was extracted with more ethyl acetate (3×100 mL)
8. dry with materialThe combined organic extracts were dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure