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Expired European patentEurope

A process for the preparation of dihydro-4,4-dimethyl-2,3-furandion

EP 0006156 B1 · Applicant: F. HOFFMANN-LA ROCHE & CO. Aktiengesellschaft

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed May 30, 1979 and granted July 1, 1981. A European patent lasts at most 20 years from filing, so its term ended May 30, 1999.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by November 30, 2004.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledMay 30, 1979
PublishedJanuary 9, 1980
GrantedJuly 1, 1981
Term endedMay 30, 1999
Application numberEP 79101658
Classification (CPC)C07D307/60

Timeline

Timeline From EPO dates

1980198219841986198819901992199419961998Application filedMay 30, 1979PublishedJan 9, 1980Patent grantedJuly 1, 1981Term endedMay 30, 1999

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.