Ethoxzolamide is used in the treatment of glaucoma, and is also used as a diuretic, acting as a carbonic anhydrase inhibitor.
alcohol dehydrogenase inhibitor, antidote
ChEBI: 1,3-Benzothiazole substituted a sulfonamide and an ethoxy group at positions 2 and 6, respectively. A carbonic anhydrase inhibitor, it has been used in the treatment of glaucoma, and as a diuretic.
Preparation of 6-Ethoxybenzothiazole-2-Sulfenamide: A solution prepared by
dissolving 21.0 grams (0.1 mol) of 6-ethoxybenzothiazole-2-thiol, Sebrell and
Boord, J. Am. Chem. Soc. 45: 2390 to 2399 (1923), in 75 ml of water
containing 5 grams of sodium hydroxide, and 75 ml of 10% sodium
hypochlorite solution were added simultaneously to 300 ml of concentrated
ammonium hydroxide which was cooled to 0°C, and vigorously stirred. During the addition the temperature was not allowed to rise above 5°C. The resulting
solid was recovered by filtration, washed thoroughly with water, and dried at
room temperature under reduced pressure. There was obtained 21 grams of
6-ethoxybenzothiazole-2-sulfenamide melting at 132° to 155°C
(decomposition). Recrystallization from ethyl acetate gave a product melting
at 140.5° to 143°C (decomposition).
Preparation of 6-Ethoxybenzothiazole-2-Sulfonamide: A solution of 3.39 grams
(0.015 mol) of the sulfenamide in 100 ml of acetone was treated dropwise,
with stirring, with a solution of 3.5 grams of potassium permanganate in 100
ml of water. The temperature rose to 42°C. After stirring an additional 10
minutes the reaction mixture was filtered to remove manganese dioxide, the
latter was washed with 100 ml of warm water, and the combined filtrates were
concentrated under reduced pressure to remove acetone. The residual solution
was treated with charcoal, filtered and acidified with concentrated hydrochloric
acid. After standing in the refrigerator for 4 hours the solid sulfonamide was
recovered by filtration, washed with water and dried. There was obtained 2.37
grams of 6-ethoxybenzothiazole-2-sulfonamide melting at 180° to 190°C.
Recrystallization from ethyl acetate-Skellysolve B gave 1.25 grams of material
melting at 188° to 190.5°C.
Diuretic, Cardiotonic, Smooth muscle relaxant,
Respiratory stimulant
6-Ethoxy-2-benzothiazolesulfonamide is a membrane permeable carbonic anhydrase inhibitor and its ocular disposition and pharmacology in normal albino rabbits has been investigated. It causes inhibition of insulin degradation in vitro.
Ethoxzolamide is another carbonic anhydrase inhibitor with properties and uses resembling those of acetazolamide.
