Method for preparing .alpha.-(4-isobutylphenyl)propionic acid or its precursor
CA 2023679 C · Owner: Tokumoto, Yuuichi · Inventors: Inoue, Satoru; Tokumoto, Yuuichi; Shimizu, Isoo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preparing .alpha.-(4-isobutylphenyl)propionic acid or its precursor is here disclosed which comprises the following steps (I), (II) and (III):, step (I): subjecting isobutylbenzene and a polyalkylbenzene to disproportionation reaction in order to form p-isobutylethylbenzene, step (II): dehydrogenating p-isobutylethylbenzene obtained in the step (I) to form p-isobutylstyrene and, step (III): the following step (IIIa) or (IIIb): step (IIIa): reacting p-isobutylstyrene obtained in the step (II) with carbon monoxide and hydrogen to prepare .alpha.-(4-isobutylphenyl)propionaldehyde or, step (IIIb): reacting p-isobutylstyrene obtained in the preceding step (II) with carbon monoxide …
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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
- Filed August 21, 1990 and granted August 18, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 21, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.