4-((1R,2S)-2-(2-(4-(1H-tetrazol-1-yl)phenoxy)ethyl)cyclopropyl)piperidine-1-carbonitrile → 5-(4-((1R,2S)-2-(2-(4-(1H-tetrazol-1-yl)phenoxy)ethyl)cyclopropyl)piperidin-1-yl)-3-isopropyl-1,2,4-oxadiazole

Participants

Reaction Steps

To a solution of 4-((1R,2S)-2-(2-(4-(1H-tetrazol-1-yl)phenoxy)ethyl)cyclopropyl)piperidine-1-carbonitrile (Step A, Example 83; 150 mg, 0.444 mmol) and N-hydroxyisobutyrimidamide (54 mg, 0.53 mmol) in tetrahydrofuran (5 mL) was added zinc chloride (1.1 mL, 0.5 M in tetrahydrofuran, 0.53 mmol). The mixture was refluxed for 2 h, cooled to RT, and concentrated to dryness under reduced pressure. The residue was dissolved in 2 mL of 4N HCl ethanol and water (1:1). The solution was refluxed for 1 hour, cooled to RT, and concentrated to dryness under reduced pressure. The residue was dissolved in methanol (5 mL), neutralized by the addition of excess potassium carbonate, mixed with silica gel (2 g), and concentrated to dryness under reduced pressure. The residue was loaded on a silica gel column (15 g of silica gel) and eluted with dichloromethane/methanol (199:1, 1 L) to provide impure product (72 mg).

Provenance & Evidence