Patent · US Expired

Synthesis of an intermediate for the preparation of 5,6-dihydro-(s)-4-(ethylamino)-(s)-6-methyl-4h-thieno [2,3-b]thiopyran-2-sulfonamide 7,7-dioxide intermediates and related compounds

US5574176A · kind A · utility

4Cited by
4References
5Claims
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Assignee

Inventors

Key dates

Filing dateApr 26, 1995
Grant dateNov 12, 1996
Priority date
Expiry dateApr 26, 2015

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07D333/34
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

This invention is concerned with an improved process for the synthesis of and intermediate en route to 5,6-dihydro-(s)-4-(ethylamino)-(s)-6-methyl-4h-thieno[2,3-b]thiopyran-2-su lfonamide 7,7-dioxide and related compounds. The instant process reduces the reaction time for the synthesis of the key intermediate from 3 to 4 days to from about 2 to about 4 hours while retaining the high enantiomeric purity of the product.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.