1,4-Dibromobenzene → 2,5-Dibromobenzenesulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

A modification of the published procedures of Moroni et al. in Macromolecules 1994, 27, 562 was used. A 300 mL round-bottom flask equipped with a reflux condenser, stirring bar, and gas inlet was charged with 1,4-dibromobenzene (50 g, 0.21 moles) and chlorosulfonic acid (100 mL). The mixture was heated to 90° C. for 2 hours under nitrogen to give a clear solution. The solution was cooled to room temperature and carefully poured onto ice (1 kg) to give a precipitate. The solids were collected by vacuum filtration, washed well with water, and air dried on the filter then dried under vacuum at 50° C. to give 68.36 g. The product was recrystallized from cyclohexane after treating with decolorizing carbon, collected by vacuum filtration, and dried at 50° C. under vacuum to give 55.37 g (79% yield) of 2,5-dibromobenzenesulfonyl chloride. 1H NMR (CDCl3): 7.66 (dd, 8.4, 2.3 Hz, 1H), 7.72 (d, 8.4 Hz, 1H), 8.30 (d, 2.3 Hz, 1H).

Provenance & Evidence