50896-04-3Relevant academic research and scientific papers
Isothiourea-Catalyzed Acylative Kinetic Resolution of Tertiary α-Hydroxy Esters
Greenhalgh, Mark D.,Laina-Martín, Víctor,Neyyappadath, Rifahath M.,Qu, Shen,Smith, Andrew D.,Smith, Samuel M.
supporting information, p. 16572 - 16578 (2020/09/09)
A highly enantioselective isothiourea-catalyzed acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiary carbinol centre. For more sterically congested alcohols, the use of a recently-developed isoselenourea catalyst was optimal, with equivalent enantioselectivity but higher conversion achieved in comparison to the isothiourea HyperBTM. Diastereomeric acylation transition state models are proposed to rationalize the origins of enantiodiscrimination in this process. This KR procedure was also translated to a continuous-flow process using a polymer-supported variant of the catalyst.
Intermolecular Radical Addition to Ketoacids Enabled by Boron Activation
Xie, Shasha,Li, Defang,Huang, Hanchu,Zhang, Fuyuan,Chen, Yiyun
, p. 16237 - 16242 (2019/10/14)
The intermolecular radical addition to the carbonyl group is difficult due to the facile fragmentation of the resulting alkoxyl radical. To date, the intermolecular radical addition to ketones, a valuable approach to construct quaternary carbon centers, remains a formidable synthetic challenge. Here, we report the first visible-light-induced intermolecular alkyl boronic acid addition to α-ketoacids enabled by the Lewis acid activation. The in situ boron complex formation is confirmed by various spectroscopic measurements and mechanistic probing experiments, which facilitates various alkyl boronic acid addition to the carbonyl group and prevents the cleavage of the newly formed C-C bond. Diversely substituted lactates can be synthesized from readily available alkyl boronic acids and ketoacids at room temperature merely under visible light irradiation, without any additional reagent. This boron activation approach can be extended to alkyl dihydropyridines as radical precursors with external boron reagents for primary, secondary, and tertiary alkyl radical additions. The pharmaceutically useful anticholinergic precursors are easily scaled up in multigrams under metal-free conditions in flow reactors.
Conclusive identification of the oxybutynin-hydrolyzing enzyme in human liver
Sato, Yuichiro,Miyashita, Aiji,Iwatsubo, Takafumi,Usui, Takashi
experimental part, p. 902 - 906 (2012/07/14)
The aim of this study was to conclusively determine the enzyme responsible for the hydrolysis of oxybutynin in human liver. Hydrolysis in human liver microsomes (HLMs) and human liver cytosol (HLC) followed Michaelis-Menten kinetics with similar Km values. In recombinant human carboxylesterase (CES)-expressing microsomes, CES1 was much more efficient than CES2 and yielded a Km value more comparable with that found in HLMs or HLC than did CES2. A correlation analysis using a set of individual HLMs, in which both CESs acted independently showed that the hydrolysis rate of oxybutynin, correlated significantly with a CES1 marker reaction, clopidogrel hydrolysis, but not with a CES2 marker reaction, irinotecan (CPT-11) hydrolysis. Chemical inhibition studies using bis-(p-nitrophenyl) phosphate, clopidogrel, nordihydroguaiaretic acid, procainamide, physostigmine, and loperamide revealed that the effects of these compounds in HLMs, HLC, and recombinant CES1-expressing microsomes were similar, whereas those in CES2-expressing microsomes were clearly different. These results strongly suggest that CES1, rather than CES2, is the principal enzyme responsible for the hydrolysis of oxybutynin in human liver. Copyright
SUBSTITUTED PHENYLCYCLOHEXYLGLYCOLATES
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Page/Page column 53, (2009/10/06)
Disclosed herein are substituted phenylcyclohexylglycolate-based muscarinic acetylcholine receptor modulators of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and methods of use thereof.
OLIGOMER-ANTICHOLINERGIC AGENT CONJUGATES
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Page/Page column 38, (2008/12/07)
The invention provides anticholinergic agents that are chemically modified by covalent attachment of a water-soluble oligomer. A conjugate of the invention, when administered by any of a number of administration routes, exhibits characteristics that are different as compared to the characteristics of the anticholinergic agent not attached to the water-soluble oligomer.
Synthesis and optimization of novel and selective muscarinic M3 receptor antagonists
Kumar, Naresh,Kaur, Kirandeep,Aeron, Shelly,Dharmarajan, Sankaranarayanan,Silamkoti, Arun D.V.,Mehta, Anita,Gupta, Suman,Chugh, Anita,Gupta, Jang B.,Salman, Mohammad,Palle, Venkata P.,Cliffe, Ian A.
, p. 5256 - 5260 (2008/02/11)
A series of constrained piperidine analogues were synthesized as novel muscarinic M3 receptor antagonists. Evaluation of these compounds in binding assays revealed that they not only have high affinity for the M3 receptor but also have high selectivity over the M2 receptor.
High performance liquid chromatographic determination of oxeladin citrate and oxybutynin hydrochloride and their degradation products
El-Gindy, Alaa
, p. 689 - 699 (2007/10/03)
Two high performance liquid chromatographic (HPLC) methods are presented for the determination of oxeladin citrate (OL) and oxybutynin hydrochloride (OB) and their degradation products. The first method was based on HPLC separation of OL from its degradation product using a Nucleosil C18 column with a mobile phase consisting of acetonitrile -0.1% phosphoric acid (60:40 v/v). The second method was based on HPLC separation of OB from its degradation product using a VP-ODS C18 column with a mobile phase consisting of acetonitrile/0.01:M potassium dihydrogen phosphate/diethylamine (60:40:0.2). Quantitation was achieved with UV detection at 220:nm based on peak area. The two HPLC methods were applied for the determination of OL or OB, their degradation products, methylparaben and propylparaben in pharmaceutical preparations. The proposed methods were used to investigate the kinetics of acidic and alkaline degradation processes of OL and OB at different temperatures and the apparent pseudofirst-order rate constant, half-life and activation energy were calculated. The pH-rate profiles of degradation of OL and OB in Britton-Robinson buffer solutions within the pH range 2-12 were studied.
3,6-DISUBSTITUTED AZABICYCLO [3.1.0]HEXANE DERIVATIVES USEFUL AS MUSCARINIC RECEPTOR ANTAGONISTS
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Page 13, (2008/06/13)
This invention generally relates to the derivatives of 3,6 disubstituted azabicyclo[3.1.0]hexanes. The compounds of this invention are muscarinic receptor antagonists which are useful, inter-alia, for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to a process for the preparation of compounds of the present invention, pharmaceutical compositions containing the compounds of the present invention and the methods for treating the diseases mediated through muscarinic receptors.
Production method of 2-cyclohexyl- 2-hydroxy-2-phenylacetic acid intermediate therefor and production method thereof
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, (2008/06/13)
The present invention relates to production of 2-cyclohexyl-2-hydroxy-2-phenylacetic acid useful as an intermediate for pharmaceutical products, by an industrial means, economically, safely in a good yield. Novel 2-(2′-cyclohexen-1′-yl)-2-hydroxy-2-phenylacetic acid ester obtained by reacting cyclohexene and benzoylformic acid ester in the presence of a Lewis acid is hydrolyzed and reduced to give 2-cyclohexyl-2-hydroxy-2-phenylacetic acid.
