Alternatively, the biphenyl trans-hydroxy triazole can be prepared using the Mitsunobu reaction conditions. To a solution of diethyl azodicarboxylate (2.0 mmol) and 3-nitrobenzoic acid (2.0 mmol) in 2.0 mL of THF is added dropwise a solution of the biphenyl hydroxy triazole (2.0 mmol, obtained from Step 1 of Example 3224), and triphenylphosphine (2.0 mmol) in 1.0 mL of THF at room temperature. The resulting solution is stirred at room temperature until the reaction is complete. The resulting mixture is diluted with ether or ethyl acetate, and washed with water. The extracts are dried (MgSO4) and concentrated in vacuo to give the biphenyl indolizinyl nitrobenzoate. The crude benzoate is hydrolyzed with LiOH in aqueous THF at room temperature and purified to give the biphenyl trans-hydroxy triazole.
