741719-53-9Relevant academic research and scientific papers
A smart library of epoxide hydrolase variants and the top hits for synthesis of (S)-β-blocker precursors
Kong, Xu-Dong,Ma, Qian,Zhou, Jiahai,Zeng, Bu-Bing,Xu, Jian-He
, p. 6641 - 6644 (2014/07/08)
Microtuning of the enzyme active pocket has led to a smart library of epoxide hydrolase variants with an expanded substrate spectrum covering a series of typical β-blocker precursors. Improved activities of 6- to 430-fold were achieved by redesigning the active site at two predicted hot spots. This study represents a breakthrough in protein engineering of epoxide hydrolases and resulted in enhanced activity toward bulky substrates. Hot pockets: Microtuning of the enzyme active pocket gives a smart library of epoxide hydrolase variants with an expanded substrate spectrum covering a series of typical β-blocker precursors. Improved activities of 6- to 430-fold were achieved by redesigning the active site at two predicted hot spots, and enhanced activity toward bulky substrates was found.
Process for preparing R-(+)-3-morpholino-4-(3- tert-butylamino-2-hydroxypropoxy)-1,2,5-thiadiazole
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Page/Page column 5-6, (2011/05/03)
The present invention provides a process for preparing optically active timolol. The process comprises the following steps. Firstly, reacting 3-hydroxy-4-morpholino-1,2,5-thiadiazole with an optically active epichlorohydrin in the presence of a solvent system, which has a first volume and a catalyst optionally in the presence of a suitable base to obtain an optically active intermediate product. Secondly, treating the optically active intermediate product with a solution, which has a second volume and comprises tert-butylamine to obtain an optically active timolol. The solvent system used in the first step can be an amide solvent, sulfoxide solvent, cyclic hydrocarbon solvent, ketone solvent, or a heterocyclic solvent. The catalyst used in the first step can be an alkali metal hydroxide, alkali metal carbonate, alkali metal hydrogen carbonate, piperidine, pyridine, triethylamine, potassium hydroxide, sodium hydroxide, potassium carbonate, and other heterocyclic bases.
Enantioselective synthesis of (S)-timolol via kinetic resolution of terminal epoxides and dihydroxylation of allylamines
Narina, Srinivasarao V.,Sudalai, Arumugam
, p. 3026 - 3030 (2007/10/03)
An efficient enantioselective synthesis of (S)-timolol has been described using chiral Co-salen-catalyzed kinetic resolution of less expensive (±)-epichlorohydrin with 3-hydroxy-4-(N-morpholino)-1,2,5-thiadiazole in good overall yield (55%) and excellent enantioselectivity (98%). Synthesis of (S)-timolol has also been achieved using hydrolytic kinetic resolution as well as asymmetric dihydroxylation routes in 90% ee and 56% ee, respectively.
Biocatalytic asymmetric synthesis of (S)- and (R)-Timolol
Tosi, Giovanni,Zironi, Federica,Caselli, Emilia,Forni, Arrigo,Prati, Fabio
, p. 1625 - 1628 (2007/10/03)
A new biocatalytic route for the synthesis of both enantiomers of Timolol (1) is described. Starting from 3,4-dichloro-1,2,5-thiadiazole (2), (R)- and (S)-Timolol (87% ee) were obtained in 35% and 30% overall yield, respectively. Asymmetric reduction of the intermediate haloketone 5 with baker's yeast afforded the corresponding halohydrin 6 in the optically active form (87% ee), which gave the R enantiomer (distomer) of Timolol. The S enantiomer (eutomer) was obtained via inversion of configuration of the halohydrin following the Mitsunobu procedure.
Arenesulfonate Derivatives of Homochiral Glycidol: Versatile Chiral Building Blocks for Organic Synthesis
Klunder, Janice M.,Onami, Tetsuo,Sharpless, K. Barry
, p. 1295 - 1304 (2007/10/02)
The preparation of a series of crystalline arenesulfonate derivatives of enantiomerically enriched glycidol is described.The enhancement of optical purity by recrystallization was particularly successful for two of these derivatives, glycidyl tosylate and glycidyl 3-nitrobenzenesulfonate, which were obtained in 97 percent ee and 99 percent ee, respectively.Very high regioselectivity was observed in the reactions of these compounds with a variety of nucleophiles, including aryl oxides, Et2AlCN, organometallic reagents, and BH3-NaBH4.The application of this methodology to the synthesis of homochiral β-adrenergic blocking agents and homochiral terminal epoxides is discussed.
