Adduct-aldehyde and its use for the preparation of a vitamin-d compound
CA 2018769 C · Owner: Halkes, Sebastianus J. · Inventors: Overbeek, Wilhelmus R. M.; Halkes, Sebastianus J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to an adduct-aldehyde of the general formula, (see figure I), wherein R is a hydrogen atom or an optionally etherified or esterified hydroxy group, R1 is an optionally etherified or esterified hydroxy group and, Z is a sulphonyl group or a group of the general formula (see figure II), ), wherein A and B are equal or different and represent C1-C4 alkoxy groups, or wherein A and B together constitute a phenylimino group or a o-phenylene group. The invention also relates to a method of preparing said adduct-aldehyde and to the use of said aldehyde as an intermediate for the preparation of vitamin-D compounds.
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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 June 12, 1990 and granted December 18, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 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.
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.