Dimethylformamide dimethyl acetal → tert-butyl 3-[(dimethylamino)methylene]-4-oxotetrahydro-1(2H)-pyridinecarboxylate
Reaktionsgleichung
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11](=[O:14])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].CO[CH:17](OC)[N:18]([CH3:20])[CH3:19]>>[C:1]([O:5][C:6]([N:8]1[CH2:9][CH2:10][C:11](=[O:14])[C:12](=[CH:17][N:18]([CH3:20])[CH3:19])[CH2:13]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]Komponenten
3
Versuchsvorschrift
A mixture of 1-tert-butoxycarbonyl piperidine-4-one and N,N-dimethylformamide dimethylacetal was stirred for 6 hours heated to reflux to give 1-tert-butoxycarbonyl-3-[(dimethylamino)methylene]piperidine-4-one. A mixture of the obtained 1-tert-butoxycarbonyl-3-[(dimethylamino)methylene]piperidine-4-one, 2-hydrazinoethanol and MeOH was stirred for two hours heated to reflux to give a mixture of 2-(5-tert-butoxycarbonyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-2-yl)ethanol and 2-(5-tert-butoxycarbonyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine-1-yl)ethanol. A mixture of the obtained mixture, 4M HCl-EtOAc solution and EtOH was stirred for two hours at room temperature to give a mixture of 2-(4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-2-yl)ethanol dihydrochloride and 2-(4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine-1-yl)ethanol dihydrochloride.