Phosphorus tribromide → 3-(Bromomethyl)-2,5-dichlorothiophene

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Reaction Steps

To a solution of (2,5-dichlorothiophen-3-yl)methanol (280 mg, 1.5 mmol) in anhydrous dichloromethane (15 mL) was added dropwise phosphorus tribromide (285 μL, 3.0 mmol). The mixture was stirred at room temperature for 3 hours. Dichloromethane was evaporated. The residue was treated with a saturated sodium bicarbonate solution until no more gas evolved. The resultant mixture was extracted with EtOAc (3×20 mL). The organic extracts were combined, dried over MgSO4, filtered, evaporated, and dried in vacuo, affording 3-(bromomethyl)-2,5-dichlorothiophene (125 mg, 34% yield). The product was used without further purification.

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