[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][OH:9])[CH:5]=[N:6][CH:7]=1.C(N(CC)CC)C.[CH3:17][S:18](Cl)(=[O:20])=[O:19]>C(Cl)Cl>[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][O:9][S:18]([CH3:17])(=[O:20])=[O:19])[CH:5]=[N:6][CH:7]=1To the stirred solution (5-bromo-pyridin-3-yl)-methanol (3.0 g, 16 mmol) in CH2Cl2 (30 mL) is added triethylamine (2.4 g, 24 mmol). The reaction mixture is cooled to 0° C., methanesulfonyl chloride (2.2 g, 19 mmol) is added slowly at 0° C. Then the reaction mixture is warmed up to room temperature for 3 hrs. Ice cold water is added and the mixture is extracted with CH2Cl2. Organic layers are combined, dried over Na2SO4 and concentrated to give 3.0 g of the crude methanesulfonic acid 5-bromo-pyridin-3-ylmethyl ester which is used without purification.
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