The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 30, 2014
Filed:
Nov. 30, 2009
Ivars Kalvinsh, Ikshkile, LV;
Antons Lebedevs, Riga, LV;
Aleksandrs Chernobrovijs, Riga, LV;
Grigory Veinberg, Riga, LV;
Maksims Vorona, Riga, LV;
Agnija Ievina, Riga, LV;
Ivars Kalvinsh, Ikshkile, LV;
Antons Lebedevs, Riga, LV;
Aleksandrs Chernobrovijs, Riga, LV;
Grigory Veinberg, Riga, LV;
Maksims Vorona, Riga, LV;
Agnija Ievina, Riga, LV;
Latvian Institute of Organic Synthesis, Riga, LV;
Abstract
The present invention provides a method for regeneration of chiral 2,2'-cyclopropylidene-bis(oxazolines), such as (3&R,3′aR,8aS,8′aS)-2,2′-cyclopropylidenebis-[3a,8a]-dihydro-8H-indeno-[1,2-d]-oxazole and (45,4′5,5R,5′R)-2,2′-cyclopropylidenebis-4,5-diphenyldihydro-4,5-oxazole, used as a part of complex catalysts for e.g. stereoselective addition reactions, from the reaction mixtures, by selective sorption of 2,2′-cyclopropylidene-bis(oxazolines) on a sorbent, such as silica gel, isolation of the sorbent from reaction mixture, desorption of 2,2′-cyclopropylidene-bis(oxazolines) from the sorbent with suitable organic solvent and final recovery of 2,2′-cyclopropylidene-bis(oxazolines) from the organic solvent used for desorption process. Catalytic quality of recovered compounds does not differ from those in freshly prepared catalysts.