2-Aminothiophenol → 2-(4-Bromophenyl)benzothiazole

Participants

Reaction Steps

A solution of 15.0 g of 4-bromobenzoic acid (74 mmol) and 13.9 g of 2-aminothiophenol (110 mmol) in 250 mL of dry toluene was heated to 45° C. and 10.1 mL of phosphorus trichloride (110 mmol) was slowly added to the reaction mixture via syringe. The mixture was allowed to reflux for 4 h. The reaction mixture was cooled to room temperature, filtered and the filtrate was concentrated under reduced pressure to afford a yellow solid. The solid was slowly added to 500 mL of saturated aq. NaHCO3 and the aqueous solution was extracted with 2×200 mL of ethyl acetate. The combined organic solutions were washed with water (3x), dried over sodium sulfate and concentrated to dryness. The crude product was purified by column chromatography to afford 6.0 g of 2-(4-bromophenyl)benzothiazole.

Provenance & Evidence