Tetrahydrofuran → 1-Boc-4-(5-methyl-1,3,4-oxadiazol-2-yl)piperidine
Reaktionsgleichung
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][CH:11]([C:14]([NH:16][NH2:17])=[O:15])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].COC(OC)N(C)C.[CH2:26]1COC[CH2:27]1>>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][CH:11]([C:14]2[O:15][C:26]([CH3:27])=[N:17][N:16]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]Komponenten
4
Reaktionsbedingungen
- Temperatur
- 50 °C
Versuchsvorschrift
To a solution of 9.0 g of 4-Hydrazinocarbonyl-piperidine-1-carboxylic acid tert-butyl ester (see reference WO 9703986 A1 19970206) (37 mmoles, 1 eq.) in 40 ml of THF, were added 8.1 ml of dimethylformamide dimethyl acetal (55.4 mmoles, 1.5 eq.). The reaction mixture was then stirred at 50° C. for 4 hours under nitrogen. The solvent was removed under reduced pressure, the residue dissolved in 40 ml of toluene, and 400 mg of para toluene sulfonic acid were added. The mixture was then heated at 100° C. under nitrogen for 18 hours, the volatiles were removed under reduced pressure and the residue was partitioned between methylene chloride and an aqueous solution of sodium bicarbonate. The organic phase was dried over magnesium sulfate and filtered. The volatiles were removed under reduced pressure and the residue was purified by column chromatography on silica gel using methylene chloride/methanol as eluant (98:2 v/v to 95:5 v/v) to afford 8.07 g of the title compound as a white solid (81%).