Process for the preparation of diaminoresorcinol
CA 2178832 A1 · Owner: Pews, Richard Garth · Inventors: Pews, Richard Garth; Lysenko, Zenon; Vosejpka, Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of producing 4,6-diaminoresorcinol comprising: a) reducing a dinitroarylether of formula (I), wherein R is hydrogen C1-C6 alkyl, cycloalkyl or CH=CH2, R' is hydrogen or CH2-R each A is independently Cl, Br, or l, and n is 0 1 or 2; to form a diaminoarylether; and b) cleaving the ether group(s) from the diaminoarylether under conditions such that 4,6diaminoresorcinol is formed as a salt or other stabilized form thereof.
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 November 15, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 15, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 15, 2016.
- 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.