To a solution of tert-butyl (2-chloro-3-formylpyridin-4-yl)carbamate (3-1, 30.5 g, 118.9 mmol) and 1-[4-(1,3-dioxolan-2-yl)phenyl]-2-phenylethanone (3-2, 29.0 g, 108.1 mmol) in anhydrous THF (300 mL) at room temperature was added LHMDS (1M in THF, 248 mL) in a stream. The reaction mixture was stirred at room temperature overnight and then it was refluxed for 24 hr. It was cooled and concentrated to a syrup and treated with NaHCO3 (saturated, 50 mL) and water (300 mL) to form a solid which was collected via filtration. The solid was dried, washed with ether and further dried with toluene azeotropically to give the title compound. LRMS m/z (M+1) Calcd: 389.1. Found 389.1.
