Method of preparing distannanes
CA 2098338 C · Owner: Stewen, Ulrich · Inventors: Stewen, Ulrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of preparing hexaalkyl distannanes by converting bis-trialkyltinoxide with a stabilized solution of sodium borohydride in alcohol, preferably methanol in the, presence of an inert solvent. The resulting compounds of general formula: R1R2R3Sn - SnR1R2R3, wherein R1 R2 and R3, are similar or dissimilar, branched or unbranched and/or substituted alkyls, are obtained in almost quantitative yields.
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 June 14, 1993 and granted November 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 14, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 14, 2015.
- 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.