Sodium Hydroxide → 6-Hydroxybenzothiazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-aminobenzothiazole (1.0 g, 6.66 mmol) in water (22 mL) and H2SO4 (16 mL) at 5° C. was added a solution of sodium nitrite (460 mg, 6.72 mmol) in water (13 mL) keeping the temperature below 5° C. The resulting solution was allowed to stir for 15 minutes. The reaction mixture was heated to 160° C. and a solution of H2SO4 (50 mL) and water (38 mL) was slowly added. The resulting mixture was allowed to stir for 1 h. The mixture was allowed to cool and an aqueous solution of 50% sodium hydroxide was added until the pH=7. The mixture was extracted with ethyl acetate and washed with brine. The combined organic was dried over MgSO4 and evaporated to yield a semi-solid. The semi-solid was purified by column chromatography (40% ethyl acetate/hexanes) to yield benzothiazo-6-ol 16 as an off-white solid.

Provenance & Evidence