Trifluoromethanesulfonic anhydride → (2-{5-[5-(5-chloro-2-oxo-2H-[1,2']bipyridinyl-5'-ylmethyl)-imidazol-1-ylmethyl]-2-cyano-phenoxy}-ethyl)-carbamic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To a cooled solution (-78° C.) of [2-(2-cyano-5-hydroxymethylphenoxy)-ethyl]-carbamic acid tert-butyl ester from step 3 (248 mg, 0.85 mmol) and 5-chloro-5'-(1-trityl-1H-imidazol-4-ylmethyl)-[1,2']bipyridinyl-2-one from Example 23, Step 5 (450 mg, 0.85 mmol) in CH2Cl2 (4.5 ml) was added DIEA (325 μl, 1.87 mmol) followed immediately by the addition of Tf2O (215 μl, 1.27 mmol). The reaction mixture stirred at -78° C. for 1 hour and was then transferred to an ice bath and stirred at 0° C. for another hour. The solvent was removed in vacuo. The residue was then dissolved in MeOH (4.5 ml) and heated to 60° C. for 4 hours. The MeOH was then removed in vacuo and the residue treated with saturated NaHCO3 and extracted with CH2Cl2. The organic layer was washed with brine, dried (MgSO4), filtered and concentrated. The residue was purified by flash chromatography with 0 to 4% MeOH(NH4OH 5%) in CH2Cl2 to yield the desired product.

Provenance & Evidence