A mixture of Example 9E (200 mg, 0.5 mmol), ethyl 3-(piperidin-4-yl)benzoate (125 mg, 0.56 mmol) in dichloroethane (20 mL) was added titanium(IV) isopropoxide (0.6 ml, 2.03 mmol) at room temperature. The mixture was stirred at room temperature for 12 hours. Sodium borohydride (96.7 mg, 2.54 mmol) and methanol (1 mL) were added to the reaction mixture and stirred for another 2 hours. LC-MS indicated that the reaction was complete. Aqueous Sodium bicarbonate (20 mL) was added to the reaction mixture. The reaction mixture was extracted with dichloromethane (3×30 mL). The organic fractions were dried with sodium sulfate, filtered, and concentrated. The residue was purified by chromatography (eluent: 20 to 80% ethylacetate in petroleum ether) on silica to give a mixture of the title compound and isopropyl benzoate.
