反应详情

To a solution of 2-(trimethylsilyl)ethyl 3-(N′-benzylidene-N-phenylhydrazino)-2-cyanoacrylate (2.69 g, 6.87 mmol) in 10 mL ethanol was added, 2.1 mL conc. HCl solution and the mixture was heated under Nitrogen at reflux for 2 hrs. The ethanol was evaporated under reduced pressure. The residue was taken up in ethyl acetate and slowly treated with 30 mL cold 1N NaOH solution. The ethyl acetate layer was separated, washed with sat. brine, and dried over MgSO4. Evaporation of the solvent afforded 1.68 g of crude material, which was purified by chromatography to afford 976 mg (47%) of 2-(trimethylsilyl)ethyl 3-amino-1-phenylpyrazol-4-carboxylate as a pale yellow solid.

1. temperatureat reflux for 2 hrs
2. customThe ethanol was evaporated under reduced pressure
3. additionslowly treated with 30 mL cold 1N NaOH solution
4. customThe ethyl acetate layer was separated
5. washwashed with sat. brine
6. dry with materialdried over MgSO4
7. customEvaporation of the solvent
8. customafforded 1.68 g of crude material, which
9. customwas purified by chromatography