Method for preparing a-(4-isobutylphenyl) propionic acid or its precursor
CA 2005845 C · Owner: Nippon Petrochemicals Co. Ltd. · Inventors: Shimizu, Isoo; Tokumoto, Yuichi; Kazumichi, Uchida
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 a step (I) of dehydrogenating p-isobutylethyl-benzene in a gaseous phase in the presence of a dehydrogenating metal catalyst to form p-isobutylstyrene and at least one unsaturated hydrocarbon compound selected from the group consisting of 4-(2'-methyl-1'propenyl)ethylbenzene, 4-(2'-methyl-1'-propenyl) vinylbenzene, 4-(2'-methyl-2'-propenyl)ethylbenzene and, 4-(2'-methyl-2'-propenyl)vinylbenzene; a step (II) of reacting p-isobutyl-styrene obtained in the step (I) with carbon monoxide and hydrogen or with carbon monoxide and water or a lower alcohol in the presence of a …
Read the whole patent
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 December 18, 1989 and granted January 9, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 18, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 18, 2011.
- 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.