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Enantioseparation of amino alcohols by reversed-phase high-performance liquid chromatography using cyanuric chloride-based chiral derivatizing reagents having amino acids and their amides as chiral auxiliaries

Bhushan R., Lal M.

Acta Chromatographica

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2014

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Vol. 26, no. 3

413--427

EN

A high-performance liquid chromatographic (HPLC) method was developed for enantioresolution of amino alcohols using an indirect approach. Two sets of chiral derivatizing reagents (CDRs) having amino acids (CDRs 1–4; set A) and their amides (CDRs 5–8; set B) as chiral auxiliaries in cyanuric chloride (CC) moiety were synthesized and characterized. Diastereomers of eight amino alcohols were synthesized, under microwave irradiation, using each of the eight CDRs. The resulting diastereomers were separated by reversed-phase high-performance liquid chromatography (RP-HPLC) using C18 column and eluting mixtures of acetonitrile with aqueous trifluoroacetic acid (aq.TFA) in a linear gradient (45 min) with UV detection at 230 nm. The results (in terms of resolution Rs and retention factor k) obtained for the two sets of diastereomers were compared among themselves and among the two groups. The effects of chiral auxiliaries (in terms of acid and amides variants), constituting CDRs, on separation were also evaluated. The elution order for the diastereomers was determined. The separation method was validated for limit of detection (LOD), linearity, accuracy, precision, and recovery.

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Synthesis of the Enantiomers of 1-{2-Hydroxy-3-[4-(2-hydroxy-phenyl)-piperazin-1-yl]-propyl}-pyrrolidin-2-one Using Soluble and Polystyrene Bound SalenCo(III)OAc Complexes as Catalysts of Hydrolytic Kinetic Resolution

Kulig K., Nowicki P., Malawska B.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 2

179-186

EN

The asymmetric synthesis of 1-{2-hydroxy-3-[4-(2-hydroxy-phenyl)-piperazin-1-yl]- propyl}-pyrrolidin-2-one 3 is described. Enantiomers of compound 3 were synthesized by hydrolytic kinetic resolution (HKR) of racemic 1-oxiranylmethyl-pyrrolidin-2-one rac-2 using soluble or polystyrene bound salenCo(III)OAc complexes folowing its aminolysis with 1-(2-hydroxy-phenyl)-piperazine. The enantiomeric purity of obtained dihydrochloride salts of compounds 3was determined by HPLC method with Chiralpack IA column. The ees determined for enantiomers of compound 3 were in range 92–96% and indicated that proposed methods are effective tools for the synthesis of aminoalcohols. The application of polystyrene bound catalyst of HKR enables its easy isolation from reaction mixture and recovery.

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Chrality Probing of Chlorotetrabutyratodiruthenium (II,III) Complexes with vic-amino Alcohols by Circular Dichroism Spectroscopy

Frelek J., Kamińska A., Pakulski Z., Szmigielski R., Priebe W.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 2

387-399

EN

The circular dichroism (CD) spectra of a variety of vic-amino alcohols in the presence of chlorotetrabutyratodiruthenium(II,III) as an auxiliary chromophore were measured in acetonitrile and chloroform. The method was tested in several model compounds containing acyclic and cyclic amino alcohols, and among them biologically important adrenergic drugs and amino sugars. The study demonstrated that the sign of the Cotton effects obtained is determined by the preferred helicity of the O-C-C-N unit in the chiral complex formed in situ. On this basis, a rule was formulated that correlates a positive (negative) sign of the O-C-C-N torsional angle with a positive (negative) Cotton effect arising around 350 nm and/or with negative (positive) signs of CD spectra bands occurring around 300 and 400 nm.

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Isoquinoline Syntheses via delta2-Oxazolines. Part VIII. Cyclization of 2-Acetamido-1,2-diphnylethan-1-ol Derivatives into Isoquinoline Systems

Kopczyński T.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 9

1317-1325

EN

(Received December 28th, 2000; revised manuscript April 25th, 2001) The results of the conversion of 2-acetamido-1,2-diphenylethan-1-ol derivatives (1) into 1-methyl-4-phenylisoquinoline derivatives (2) have been described. The mechanism proposed for these reaction assumes the existence of protonated 2-oxazolines (3), carbonium ions (4), and unsaturated amides (5 and 6) as intermediates.