To a solution of 2-dimethylaminoethanol (0.46 mL, 4.56 mmol) in hexane (7.0 mL, HPLC grade) cooled at −5° C. was added drop wise n-BuLi (1.60 M, 5.70 mL, 9.12 mmol) under nitrogen atmosphere. After 30 min at 0° C., 4-pyridin-2-yl-morpholine (0.25 g, 1.52 mmol) in hexane (2.0 mL) was added drop wise. After stirring the reaction mixture for 1 h at 0-5° C., the reaction medium was cooled to −78° C. followed by drop wise addition of tributyl tin chloride (1.03 mL, 3.70 mmol). The resulting reaction mixture was stirred at −78° C. for 30 min and then allowed to stir at 0-5° C. for 2 h. The reaction mixture was then allowed to come to room temperature. After the completion of reaction (TLC monitoring), the reaction mass was cooled to 0° C. and water was added slowly. The aqueous phase was extracted with diethyl ether (3×20 mL). The combined organic layers were dried over anhydrous Na2SO4, and evaporated to dryness. The crude residue was purified over silica gel (230-400 M) using EtOAc-Hexane (2:98) to provide the compound as yellow oil (0.050 g, 7.20%).
