Method for producing 2,4-dihydroxyquinoline derivatives
CA 1308415 C · Owner: Imaki, Naoshi · Inventors: Oishi, Mari; Takuma, Yuki; Imaki, Naoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a 2,4-dihydroxyquinoline derivative of the formula:, (II), wherein each of R1 R2, R3 and R4 is a hydrogen atom, a, lower alkyl group a lower alkoxy group or a halogen atom and its tautomer, which comprises cyclizing an aryl malonic acid amide ester derivative of the formula: (I), wherein R1, R2, R3 and R4 are as defined above and R5 is, a lower alkyl group, by means of polyphosphoric acid.
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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 October 6, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 6, 2009.
- 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
Timeline From CIPO dates
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.