Process for the preparation of enantiomerically pure pyrethroid insecticides
CA 2413472 C · Owner: Syngenta Participations Ag · Inventors: Gott, Brian David; Brown, Stephen Martin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing compounds of formula (VIIa) and (VIIb) wherein X is a leaving group; Y and Y1 are idependently Cl or Br; and Z is Cl Br or a , haloalkyl group which process comprises a) reacting a compound of formula (VII) wherein X, Y, Y1 and Z are as defined for compounds (VIIa) and (VIIb) with a substantially optically pure chiral amine in a solvent to form a diastereoisomeric salt; b) separating the diastereomeric salt of each enantiomer; c) converting the diastereomeric salt of each anantiomer separately to compounds of formulae (VIIa) and (VIIb) respectively by acid or base hydrolysis, the use of the compounds in making pyrethroid insecticides and novel intermediates.
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 July 16, 2001 and granted April 19, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 16, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 2023.
- 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.