Hydrochloric Acid → 6-chloronaphthalene-2-sulfonic Acid

Participants

Reaction Steps

6-Amino-2-napthalenesulfonic acid (88.0 g, 0.4 mol) was suspended in 5 N HCl (200 mL) and water (150 mL) and cooled to 3° C. A solution of sodium nitrite (27.0 g, 0.4 mol) in water (50 mL) was added dropwise over two hours. After one additional hour, the mixture was poured in several portions into a stirred suspension of copper(I) chloride (39.6 g, 60.6 mmol) in 5 N HCl (200 mL). Considerable foaming occurred during this addition. After standing overnight at room temperature, the mixture was concentrated on a rotary evaporator to a brown solid that was then dried in a vacuum oven overnight at 100° C. to provide the acid (111.9 g).

Provenance & Evidence