Imidazole → HCID 23525647, Verbindung

Beteiligte Stoffe

Reaktionsschritte

A solution of diethyl azodicarboxylate (49.6 mL, 0.315 mol) was added dropwise to a stirred mixture of tert-butyl 4-{4-chloro-2-[(1R)-1-hydroxyethyl]phenyl}-3,6-dihydropyridine-1(2H)-carboxylate (3-5) (26.7 g, 78.9 mmol), Zn(N3)2.2Py (prepared according to the method described by Viaud, M-C; Rollin, P. in Synthesis, 1990: 130-131) (48.5 g, 0.158 mol), triphenylphosphine (82.7 g, 0.315 mol) and imidazole (21.5 g, 0.315 mol) in dichloromethane at approximately 0° C. After the addition, the resulting mixture was allowed to warm to ambient temperature and stirred vigorously for 3 d. The reaction mixture was filtered through a short column of silica gel eluted with the appropriate volume of dichloromethane to remove excess salts and polar byproducts. The filtrate was concentrated in vacuo and the crude residue was purified by flash chromatography on silica gel (12.5% ethyl acetate/hexanes as eluent) to furnish 3-6 (23.9 g) as a viscous pale yellow oil.

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