To a mixture of methyl 2-(4-(4-(5-aminopyridin-2-yl)phenyl)-2-oxabicyclo[2.2.2]octan-1-yl)acetate (286 mg, 0.812 mmol) in neat benzyl alcohol (6 mL, 57.9 mmol) was added titanium(IV) isopropoxide (1.5 mL, 5.12 mmol) and 4 A molecular sieves (5 g, 0.812 mmol). The reaction mixture was heated at 130° C. overnight. The reaction was quenched by saturated NaHCO3 and was extracted with EtOAc. The combined organic layer was filtered and washed with brine and dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by prep-HPLC (15 to 90% ACN-water (0.1% NH4OH) with X-bridge C18 column) to give the title compound after drying (150 mg, 43% yield). LC/MS, ESI-MS(+): 429.1, RT: 1.41 (Condition E).
