Dimethylformamide → 5-bromonaphthalene-2-sulfonyl Chloride

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Reaction Steps

To a round bottom flask was added 5-bromonaphthalene-2-sulfonic acid (5.00 g, 17.41 mmol), followed by DMF (17.41 mL) to generate a deep green heterogeneous solution. Thionyl chloride (2.54 mL, 34.8 mmol) was added dropwise using a syringe at rt, and the solution turned orange and heat was evolved. The solution became homogeneous. The solution was maintained at rt for 18 h. The resulting orange solution was poured into a separatory funnel containing ice and diluted with DCM (200 mL). When the ice melted, the mixture was shaken and then the resulting layers were separated. The aqueous layer was extracted with DCM (1×50 mL). The combined organic layers were washed with water (3×200 mL), then dried over Na2SO4 and concentrated to provide 5-bromonaphthalene-2-sulfonyl chloride (5.00 g, 16.36 mmol) as a brown oil, which was used immediately without further purification.

Provenance & Evidence