[Br:1][C:2]1[S:3][C:4]([CH2:8][OH:9])=[C:5]([CH3:7])[N:6]=1.C(N(CC)CC)C.[CH3:17][S:18](Cl)(=[O:20])=[O:19].O>ClCCl>[Br:1][C:2]1[S:3][C:4]([CH2:8][O:9][S:18]([CH3:17])(=[O:20])=[O:19])=[C:5]([CH3:7])[N:6]=1To an ice-cold solution of (2-Bromo-4-methyl-thiazol-5-yl)-methanol (3.2 g, 15.6 mmol) and triethylamine (3.2 mL, 23.4 mmol) in dichloromethane (80 mL) is slowly added a solution of methanesulfonyl chloride (2.1 g, 18.7 mmol) in dichloromethane (20 mL). The mixture is kept at this temperature for 45 minutes and afterwards allowed to warm to room temperature. Water (30 mL) is added after 3 hours and the mixture is extracted with ethylacetate. The organic phase is separated and dried over MgSO4. The organic solvent is removed under reduced pressure to give 3.0 g of Methanesulfonic acid 2-bromo-4-methyl-thiazol-5-ylmethyl ester, which was used without further purification.
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