| 摘要 |
The present invention relates to one-pot process for the preparation of 6-substituted-4-oxo-thieno[2,3b]thiopyran-2-sulfonic acid of formula (I), which comprises, reacting 2-thienylthiol with alkenyl acid in the presence of an aromatic hydrocarbon solvent and a base, cyclization of the resulting compound and further reacting with an acid anhydride and sulfuric acid to get the desired compound of formula (I). The compound of formula (I) is the key intermediate in the preparation of (S,S)-5,6-dihydro-4-alkyylamino-6-substituted-4H-thieno[2,3-b]thiopyran-2-sulfonamide-7,7-dioxide and analogs thereof.
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