CYCLISATION SUBSTRATES, CYCLISATION PROCESS AND RELATED 11.beta.-AXIALLY-SUBSTITUTED STEROIDS
CA 1134812 A · Owner: Akzona Incorporated · Inventors: Broess, Arnoldus I.A.; Zeelen, Filippus J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
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The cyclisation of compounds of the formula: (I), wherein:, (a) R1 is H or alkyl of one to four carbon atoms; (b) R2 is H or alkyl of one to four carbon atoms with the proviso that R1 is H when R2 is alkyl and with the proviso that R2 is H when R1 is alkyl; (c) R3 is a suitable leaving group selected from the group consisting of hydroxy, alkoxy of one to four carbons, alkoxyalkoxy of two to four carbons acyloxy of one to about seven carbon atoms and, trialkylsilyloxy of less than fifteen carbons; (d) R4 is H, hydrocarbyl of one to fourteen carbons carboxyacyl of two to twelve carbons, trialkylsilyl of less than fifteen carbons, or heterocyclic of five to seven atoms and four to six carbons; …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted November 2, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 2, 1999.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.