Reaktion #8336

Reaktionsgleichung

(1-pyridin-2-yl-2-quinolin-4-yl-ethylidene)-hydrazine

ethyl chloroformate

→

title compound

5-Pyridin-2-yl-4-quinolin-4-yl-2H-pyrazol-3-ol

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution is refluxed for 12 h
2. 2
   Einengenconcentrated in vacuo
3. 3
   workup.ADDITIONThe residue is treated with dichloromethane/methanol
4. 4
   Filtrationthe precipitate collected by vacuum filtration
5. 5
   SonstigeThe precipitate is triturated with ethanol

Vorschrift

To a solution of (1-pyridin-2-yl-2-quinolin-4-yl-ethylidene)-hydrazine (2.0 g, 7.6 mmol) in pyridine (20 mL) at 0° C. is added ethyl chloroformate (2 mL) dropwise. The mixture is warmed to room temperature and stirred for 2 h. The solution is refluxed for 12 h and concentrated in vacuo. The residue is treated with dichloromethane/methanol and the precipitate collected by vacuum filtration. The precipitate is triturated with ethanol to yield the title compound, 300 mg (13%), as a white solid.

Quelle