Patent ID: 7030250

Claim:
A process for obtaining 4-(N-alkylamino)-5,6-dihydro-4H-thien-(2,3-b)-thiopyran-2-sulfonamide-7,7-dioxides of general formula (I) wherein R 1 is H or C 1-5 alkyl, and R 2 is C 1-5 alkyl, their individual cis or trans diastereomers, their individual levo or dextro enantiomers, or isomeric mixtures thereof, and pharmaceutically acceptable salts thereof, which comprises a) protecting the nitrogen present in the aminosulfone of formula (II) wherein R 1 and R 2 have been defined earlier, with a nitrogen protecting group to obtain an N-protected aminosulfone of formula (III) wherein R 1 and R 2 are as previously defined and P is a nitrogen protecting group; b) introducing a sulfonamide group at position 2 of said N-protected aminosulfone (III) to obtain the sulfonamide intermediate of formula (VI) wherein R 1 and R 2 are as previously defined and P is a nitrogen protecting group; and c) eliminating the nitrogen protecting group to obtain the compound of formula (I).