Process for removing sulfonyl groups from benzimidazole isomers
CA 1187889 A · Owner: Eli Lilly And Company · Inventors: Wikel, James H.; Morwick, Tina M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention concerns a process for removing a sulfonyl group from the l-position of a benzimidazole to allow conversion of 2-amino-1,5substituted-benzimidazole compounds into 2-amino- 1,6-substituted-benzimidazole compounds. The 5-isomer is reacted with an alkali metal hydroxide or carbonate in an inert aqueous organic solvent system. The reaction mixture is acidified to precipitate the base and form the intermediate benzimidazole tautomer. The intermediate is then reacted with a sulfonyl acylating agent or a haloalkyl isothiocyanate to form a mixture of 2-amino-1,5(6)-substituted-benzimidazole compounds. This invention also concerns the process for removing a sulfonyl group from the …
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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
- Granted May 28, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 28, 2002.
- 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
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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.