3,3-d1-substituted phthalides and intermediates and processes
CA 1088938 A · Owner: Sterling Drug Inc. · Inventors: Crounse, Nathan N.; Schmidt, Paul J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process comprises the combination of the three steps of condemsing 3-N(R)2-4-X-benzoic acid with an aromatic or heterocyclic aldehyde, YiCHO, under acidic conditions to produce 3-Y-5- X-6-N(R)2phthalide (II), condensing said phthalide with a compound of the formula Z-H under alkaline or acid conditions to produce 2-(.alpha.-Y-.alpha.-Z)methyl-4-X-5-N(R)2benzoic acid (III) and oxidizing, said benzoic acid to produce 3-Y-3-Z-5-X-6-N(R)2phthalide (I) where: R is hydrogen, non-tertiary alkyl of one to four carbon atoms, benzyl or substituted benzyl; X is hydrogen or halo; Y is 4-R1-3-R2-2-R1-phenyl, 1-R5-2-R6-5/6-R4-3-indolyl 9-R7-3-, carbazolyl, 9-julolidinyl, 3,4-dioxymethylenephenyl …
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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 4, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 4, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.