- Resolution of racemic flurbiprofen by lipase-mediated esterification in organic solvent
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Resolution of rac-flurbiprofen, 2-fluoro-α-methyl-[1,1'-biphenyl]-4-acetic acid (1), by biocatalytic methodologies has been studied. Enzymatic hydrolysis of rac-flurbiprofen methyl ester (2) in aqueous-organic medium gave poor results. Transesterification of the same ester mediated by immobilized lipase from Candida antarctica (Novozym 435) in organic solvent proceeded with good enantiomeric excess but the isolation of the product required chromographic separation and therefore was unsuitable for large scale preparation. Direct esterification of 1 with methanol in acetronitrile promoted by Novozym 435 proved to be the best method since it gave, via a twofold kinetic resolution, S-flurbiprofen with excellent enantiomeric excess. The R-flurbiprofen methyl ester formed in the reaction can be converted into the starting rac-flurbiprofen by alkaline hydrolysis or, alternatively, into R-flurbiprofen by hydrolysis with acid.
- Morrone,Nicolosi,Patti,Piattelli
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- Suzuki-Miyaura coupling of aryl carbamates, carbonates, and sulfamates
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(Chemical Equation Presented) The first Suzuki-Miyaura cross-couplings of carbamates, carbonates, and sulfamates is described. The method provides a powerful means of using simple derivatives of phenol as precursors to polysubstituted aromatic compounds, as exemplified by a concise synthesis of the anti-inflammatory drug flurbiprofen.
- Quasdorf, Kyle W.,Riener, Michelle,Petrova, Krastina V.,Garg, Neil K.
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supporting information; experimental part
p. 17748 - 17749
(2010/04/01)
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- ESTERS OF ARYLPROPIONIC ACIDS WITH 1,2:5,6-DI-O-ISOPROPYLIDENE- AND 1,2-O-ISOPROLYLIDENE-α-D-GLUCOFURANOSE
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On fractional crystallization of 3-O-(2-(2-fluoro-4-biphenylyl)propionyl-, 3-O-(2-(4-isobutylphenyl)propionyl)- and 3-O-(2-(6-methoxy-2-naphthyl)propionyl)-1,2:5,6-di-O-isopropylidene-α-D-glucofuranoses V - VII optically pure R-diastereoisomers were isolated.The derivatives of 1,2-O-isopropylidene-α-D-glucofuranose obtained on partial deacetylation of esters V - VII were separated chromatographically to R and S-diastereoisomers.Their hydrolysis or transesterification afforded optically pure arylpropionic acids or their methyl esters, respectively.Kinetic resolutionof the acids gives rise to esters V - VII enriched in R-diastereoisomer.
- Svoboda, Jiri,Capek, Karel,Palecek, Jaroslav
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p. 766 - 774
(2007/10/02)
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