Method of preparing an intermediate for the manufacture of bambuterol
CA 2045554 A1 · Owner: Aktiebolaget Astra · Inventors: Jaksch, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
57) Abstract, The present invention relates to an improved method for the preparation of an intermediate for bambuteroi? for the preparation of 2'-bromo-3,5-diN,N-dimethylcarbamoyloxyacetophenone (1) by reacting 3,5-dihydroxyacetophenone with N,Ndimethylcarbamoylchloride in ethyl acetate isopropylacetate butylacetate, ethylmethylketone or isobutylmethylketone as a solvent with small amount of pyridine as a catalyst and using crystallized potassium carbonate as a base quenching with water, removing the solvent and dissolving of the resulting 3,5-diN,N-dimethylcarbamoyloxyacetophenone in ethyl acetate to which, dissolved hydrogen bromide is added and then bromine whereupon the resulting …
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 29, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 29, 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.