1-Piperazinecarboxylic acid, ethyl ester → Ethyl 4-(3-fluoro-2-pyridinyl)-1-piperazinecarboxylate
Reaktionsgleichung
Cl[C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][N:3]=1.[CH3:9][CH2:10][O:11][C:12]([N:14]1[CH2:19][CH2:18][NH:17][CH2:16][CH2:15]1)=[O:13]>C(O)CCC>[F:8][C:7]1[C:2]([N:17]2[CH2:16][CH2:15][N:14]([C:12]([O:11][CH2:10][CH3:9])=[O:13])[CH2:19][CH2:18]2)=[N:3][CH:4]=[CH:5][CH:6]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of 2-chloro-3-fluoropyridine (650 mg, 5.06 mmol) and ethyl N-piperazinocarboxylate (1.61 g, 10.2 mmol) in 60 ml of n-butanol is stirred at reflux under nitrogen for 18 hours. After concentrating to dryness under reduced pressure, the residue is dissolved in a mixture of ethyl acetate and water. The ethyl acetate extract is washed again with water, dried over anhydrous sodium sulfate, filtered and concentrated. The N-carbethoxy derivative of 1-(3-fluoro-2-pyridinyl)piperazine is further purified by chromatography over silica gel 60 (230-400 mesh).