Benzyl Alcohol → 1-Tert-butyloxycarbonyl-trans-3-benzyloxycarbonylamino-4-(2-pyridyl)pyrrolidine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-tert-butyloxycarbonyl-trans-4-(2-pyridyl)pyrrolidine-3-carboxylic acid from step 5 above (13 mmol) in toluene (50 mL) was added DIEA (3.0 mL, 17 mmol). The solution was cooled to 0° C. and diphenylphosphoryl azide (4.1 g, 15 mmol) was added. The resulting solution was stirred at 0° C. for 1 h and at ambient temperature for 4 h. Benzyl alcohol (2.8 g, 26 mmol) was added and the solution was refluxed for 3 h. The solution was cooled to ambient temperature, diluted with EtOAc, and washed with aqueous NaHCO3. The organic phase was separated, dried over MgSO4, filtered, and the solvents were removed in vacuo. The residue was purified by flash column chromatography using a gradient elution of 10-25% EtOAc:hexanes to give the title compound as an oil (3.9 g, TLC Rf=0.4, 1:3 EtOAc-hexanes; HPLC RT=6.67 min, method A).

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