4-Hydroxypiperidine-1-carbonitrile → 1-(3-Isopropyl-1,2,4-oxadiazol-5-YL)piperidin-4-OL

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Reaction Conditions

Reaction Steps

4-Hydroxypiperidine-1-carbonitrile (3.0 g) and N-hydroxy-2-methylpropanimidamide (2.9 g) are dissolved in ethyl acetate (20 ml) and 1 M ZnCl2 in Et2O (29 ml) is added. A precipitate forms and the solvent is decanted off. Additional Et2O (20 ml) is added to wash the precipitate and is decanted off. EtOH (20 ml) is added followed by conc. HCl (7.5 ml) and the mixture is heated to 100° C. for 3.5 h. The mixture is concentrated, redissolved in H2O (5 ml) and made basic by addition of concentrated NaHCO3. The aqueous layer is extracted with dichloromethane (2×50 mL) and the organic layer is dried over MgSO4, filtered and concentrated. The crude product is purified by silica gel chromatography (0% to 100% ethyl acetate/hexanes) to afford the title compound. LC (method 20): tR=1.56 min; Mass spectrum (APCI): m/z=212 [M+H]+.

Provenance & Evidence