Asymmetric synthesis of benzoxazinones
CA 2275323 C · Owner: The Dupont Merck Pharmaceutical Company · Inventors: Choudhury, Anusuya; Pierce, Michael Ernest; Parsons, Rodney Lawrence Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides novel methods for the asymmetric synthesis of (S)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1benzoxazin-2-one of formula (VI-i) which is useful as a human immunodeficiency virus (HIV) reverse transcriptase inhibitor.
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 15, 1997 and granted April 8, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 15, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 15, 2019.
- 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.