Cerebrovasodilatation through selective inhibition of the enzyme carbonic anhydrase. 3. 5-(Arylthio)-, 5-(arylsulfinyl)-, and 5-(arylsulfonyl)thiophene-2-sulfonamides.

A series of 5-(arylthio)-, 5-(arylsulfinyl)-, and 5-(arylsulfonyl)thiophene-2-sulfonamides is described and anticonvulsant activities are listed for the compounds. In most cases, the sulfones had the highest activity and the sulfides the least. Sulfones with 3- or 4-halo substituents generally had the highest activity, and one analogue, 5-[(4-fluorophenyl)sulfonyl]thiophene-2-sulfonamide (51, UK-17022), had an anticonvulsant ED50 fo 2 mg/kg when administered orally to mice. Compound 51 selectively increased cerebral blood flow in animals without an unacceptable level of diuresis.