Hydrochloric Acid → 4-Bromo-3-chlorobenzenethiol

Participants

Reaction Conditions

Reaction Steps

4-Bromo-3-chloro-benzenesulfonyl chloride (3.78 g, 13.0 mmol) was dissolved in dichloromethane (40 ml) and DMF (1.0 ml) was added. The mixture was cooled to 0° C. under argon and triphenylphosphine (10.26 g, 39.0 mmol) was added slowly, then the mixture was allowed to return to room temperature with stirring over 16 h. Hydrochloric acid (1 M, 75 ml) was added and the layers were separated. The organic layer was concentrated and the residue suspended in 1 M aqueous sodium hydroxide (75 ml) and filtered. The filtrate was extracted with Et2O (×2), then neutralised (1 M HCl, 75 ml). The mixture was then extracted (Et2O×3) and the combined organic layers were dried (Na2SO4) and concentrated to afford the title compound as a colourless oil (0.94 g, 32%). 1H NMR (CDCl3 400 MHz) 3.49 (1H, s), 7.02 (1H, dd, J=8.35, 2.24 Hz), 7.38 (1H, d, J=2.18 Hz), 7.45 (1H, d, J=8.35 Hz).

Provenance & Evidence