Ammonium Hydroxide → Ethoxzolamide

Participants

Reaction Conditions

Reaction Steps

A solution of ammonium hydroxide (650 mL) was cooled to 0° C. in an ice/methanol bath. A solution containing 6-ethoxy-2-mercapto-benzothiazole (16.0 g, 0.076 mol) in 170 mL of 5% NaOH and a solution of 5.25% NaOCl (150 mL) were added simultaneously to the ammonium hydroxide solution while maintaining a temperature of 0° C. The reaction was stirred for 15 min. upon completing the addition, and the sulfenamide was collected by vacuum filtration. The sulfenamide was dissolved in 1 L of acetone and oxidized by the addition of 450 mL of 5% KMn04 over 4 hours. The MnO2 was removed by filtering through Celite, and the acetone was removed under vacuum. The product was precipitated from solution by acidification with concentrated HCl to yield 11.7 g (59.7%) of 6-ethoxy-2-benzothiazolesulfonamide, which was purified by dissolving it in 5% NaOH, filtering, and precipitating with concentrated HCl; mp 190°-191° C.; MS, m/e 258 (M,calcd 258).

Provenance & Evidence