Large scale, non-chromatographic purification of chromogenic cryptahemispherands (1.1) and (2.1)
CA 2037281 A1 · Owner: Technicon Instruments Corporation · Inventors: Czech, Bronislaw P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for the non-chromatographic purification of chromogenic cryptahemispherands of the following general formula (II) which are capable of selective binding of sodium ion in aqueous solution:, (II), wherein:, R, same or different is hydrogen, lower alkyl, lower alkylidene lower alkenyl, allyl, aryl or benzyl;, R' same or different, is lower alkyl, lower alkylidene lower, alkenyl, allyl, aryl or benzyl; R", same or different, is hydrogen, lower alkyl lower, alkylidene, lower alkenyl, allyl aryl or benzyl;, Z is halogen;, Y is electron withdrawing group e.g. CN, NO2, CF3, COOR;, m is 1 to 3; n is 1 to 3;, a is 1 to 3;, b is 1 to 3; k is 1 to 2;, 1 is 1 to 2;, k and 1 are …
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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 February 28, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 2013.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.