Step 1: Synthesis of 2-bromo-5-(bromomethyl)thiazole. 2-Bromo-5-methylthiazole (1 g, 5.6 mmol) and N-bromosuccinimide (1.1 g, 6.18 mmol, 1.1 eq.) were dissolved in a solvent mixture of 40 mL of dichloromethane and 40 mL of water. The reaction mixture was stirred at 90 °C under UV irradiation. The reaction setup was a round-bottomed flask equipped with a reflux condenser and the reaction lasted for 3 hours. After completion of the reaction, the mixture was cooled to room temperature and transferred to a split funnel for extraction. The aqueous phase was extracted twice more with dichloromethane, and all organic phases were combined and dried with anhydrous magnesium sulfate. The dried organic phase was filtered through cotton, concentrated and purified by automated column chromatography using a gradient elution of hexane solution with 0% to 3% ethyl acetate to give the target product 2-bromo-5-(bromomethyl)thiazole 1.24 g in 78% yield. The product was confirmed by 1H NMR (400 MHz, CDCl3): δ 7.46 (d, J=0.9 Hz, 1H), 4.57 (d, J=0.9 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 141.92, 139.80, 137.39, 22.37; Mass Spectra (ESI): m/z 255.8 [M +H]+.
