Hydrochloric Acid → 1-Naphthalenesulfinic acid

Participants

Reaction Steps

To a vigorously stirred solution of sodium bicarbonate (8.4 g, 100 mmol) and anhydrous sodium sulphite (12 g, 95 mmol) in water (50 ml) at 70°-80° C., was added naphthalene-1-sulphonyl chloride (11.5 g, 50 mmol) in portions and with vigorous stirring. The temperature was kept at 70°-80° C. by intermittent heating. When the addition was complete, the mixture was heated and stirred at 70°-80° C. for a further hour. The mixture was then allowed to cool to room temperature over 4 hours and acidified with 2M hydrochloric acid. The precipitated solid was collected by filtration, washed with water, air dried and then recrystallised from aqueous ethanol to give naphthalene-1-sulphinic acid as a solid (6.0 g), m.p. 86 87° C.

Provenance & Evidence