Selective 6-acylation of sucrose mediated by cyclic adducts of dialkyltin oxides and diols
CA 2038740 C · Owner: Vernon, Nicholas M. · Inventors: Walkup, Robert E.; Wingard, Robert E. Jr.; Vernon, Nicholas M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a process which comprises the steps of:, (a) reacting a di(hydrocarbyl)tin oxide such as a dialkyltin oxide with a dihydric alcohol alkanolamine, or, an enolizable .alpha.-hydroxy ketone in an inert organic reaction vehicle, with removal of water at a temperature, and for a period of time sufficient to produce a cyclic adduct of said dialkyltin oxide and said dihydric alcohol alkanolamine, or enolizable .alpha.-hydroxy ketone; (b) reacting said cyclic adduct product of Step (a) with sucrose in an inert organic reaction vehicle such as a dipolar aprotic liquid, at a temperature and for a period of time sufficient to produce a 6-O-dihydrocarbyl- (hydroxy- or amino- or …
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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
- Filed March 21, 1991 and granted October 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 21, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 21, 2013.
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