[Cl:1][C:2]1[CH:7]=[C:6]([OH:8])[C:5]([Cl:9])=[CH:4][N:3]=1.CC(C)([O-])C.[Na+].Br[CH2:17][CH:18]1[CH2:21][CH2:20][CH2:19]1>C1COCC1.CN(C=O)C>[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH2:17][CH:18]2[CH2:21][CH2:20][CH2:19]2)[C:5]([Cl:9])=[CH:4][N:3]=1To a solution of 2,5-dichloro-4-pyridinol (CAN 847664-65-7, 660 mg, 4.02 mmol) in THF (20 mL) and DMF (20 mL) was added with stirring sodium tert-butoxide (1.16 g, 12.1 mmol) and (bromomethyl)-cyclobutane (CAN 17247-58-4, 2.26 mL, 20.1 mmol). The resulting mixture was stirred at 80° C. for 20 h, cooled and concentrated. The residue was partitioned between water and ethyl acetate; the organic portions were combined, dried over Na2SO4, filtered and concentrated. The crude material was purified by flash chromatography (silica, heptane/ethyl acetate gradient) to give the title compound (466 mg, 50%) as white solid. LC-MS (UV peak area, m/z) 97.8%, 232.0293 (MH+).
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