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Isopropyl Ester (isopropyl + ester)

Distribution by Scientific Domains
Chemistry60%
Medical Sciences40%

Kinds of Isopropyl Ester

  • acid isopropyl ester
    		•

    Selected Abstracts

    Comparative Reactivity of Hypervalent Iodine Oxidants in Metalloporphyrin-Catalyzed Oxygenation of Hydrocarbons: Iodosylbenzene Sulfate and 2-Iodylbenzoic Acid Ester as Safe and Convenient Alternatives to Iodosylbenzene

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009

    Abstract A comparative study of the reactivity of 2-iodylbenzoic acid isopropyl ester (IBX-ester), oligomeric iodosylbenzene sulfate [(PhIO)3,SO3]n, and iodosylbenzene in the oxygenation of anthracene in the presence of metal porphyrin or phthalocyanine complexes is reported. Results of this study demonstrate that oligomeric iodosylbenzene sulfate and the IBX-ester are the most reactive oxygenating reagents that can be used as a safe and convenient alternative to the thermally unstable and potentially explosive iodosylbenzene. [source]

    1,3-Dihydro-2H -imidazo[4,5- c]pyridin-2-one

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2006
    Jarle Holt
    A facile acid catalysed cyclisation method for the preparation of the cyclic urea 2H -imidazo[4,5- c]pyridin-2-one (2) in > 95 % yield is reported. The biologically active compound 2 can be obtained by heating (3-amino-4-pyridinyl)-carbamic acid methyl, ethyl or tert -butyl esters (1a-c) in sulfuric acid (0.1 %) or in aqueous HBF4 (3.5 equivalents) for 10 min. - 3 hrs at 90 °C. The corresponding microwave-promoted (MW) reactions afforded the pure product 2 within few minutes. The 6-butylamino-substituted analogue (2a) was correspondingly obtained by MW irradiation in 99 % yield by cyclisation of 2-(butylamino)-5-amino-4-pyridylcarbamic acid isopropyl ester (1d). Quantitative precipitation of product 2 was obtained by pH adjustment. The process represents a solvent-free, "green" method for the preparation of 2. [source]

    Formation of a defluorinated metabolite of a quinoxaline antiviral drug catalysed by human cytochrome P450 1A2

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2001
    Peter J. Mutch
    The in-vitro metabolism of GW420867X ((S)-2-ethyl-7-fluoro-3-oxo-3, 4-dihydro-2H-quinoxaline-1-carboxylic acid isopropyl ester), a quinoxaline drug for the potential treatment of HIV, has been studied with singly expressed human cytochromes P450 (CYP 450). No biotransformation of [14C]GW420867X was evident in the presence of any of the CYP 450 isoforms, with the exception of CYP 450 1A2, where a single metabolite was observed in the HPLC radiochromatograms of enzyme incubations with the test compound. The structure of this metabolite was determined by nuclear magnetic resonance spectroscopy and mass spectrometry, and was shown to correspond to the replacement of the aromatic fluorine of GW420867X with a hydroxyl group. Thus, it appeared that CYP 450 1A2 catalysed the specific defluorination of GW420867X, presumably during formation of an arene oxide intermediate during aromatic hydroxylation. [source]

    Changes of GABA receptors and dopamine turnover in the postmortem brains of parkinsonians with levodopa-induced motor complications

    MOVEMENT DISORDERS, Issue 3 2003
    Frédéric Calon PhD
    Abstract Brain samples from 14 Parkinson's disease patients, 10 of whom developed motor complications (dyskinesias and/or wearing-off) on dopaminomimetic therapy, and 11 controls were analyzed. Striatal 3,-(4- 125I-iodophenyl)tropane-2,-carboxylic acid isopropyl ester ([125I]RTI-121) -specific binding to dopamine transporter and concentration of dopamine were markedly decreased, but no association between level of denervation and development of motor complications was observed. The homovanillic acid/dopamine ratio of concentrations was higher in putamen of patients with wearing-off compared to those without. Striatal 35S-labeled t-butylbicyclophosphorothionate ([35S]TBPS) and [3H]flunitrazepam binding to GABAA receptors were unchanged in patients with Parkinson's disease, whereas [125I]CGP 64213 -specific binding to GABAB receptors was decreased in the putamen and external segment of the globus pallidus of parkinsonian patients compared with controls. [3H]Flunitrazepam binding was increased in the putamen of patients with wearing-off compared to those without. [35S]TBPS,specific binding was increased in the ventral internal globus pallidus of dyskinetic subjects. These data suggest altered dopamine metabolism and increased GABAA receptors in the putamen related to the pathophysiology of wearing-off. The present results also suggest that an up-regulation of GABAA receptors in the internal globus pallidus is linked to the pathogenesis of levodopa-induced dyskinesias. © 2002 Movement Disorder Society [source]

    Lipophilicity Plays a Major Role in Modulating the Inhibition of Monoamine Oxidase B by 7-Substituted Coumarins

    CHEMISTRY & BIODIVERSITY, Issue 2 2006
    Angelo Carotti
    Abstract A series of coumarin derivatives (1,22), bearing at the 7-position ether, ketone, ester, carbamate, or amide functions of varying size and lipophilicity, were synthesized and investigated for their in vitro monoamine oxidase-A and -B (MAO-A and -B) inhibitory activities. Most of the compounds acted preferentially as MAO-B inhibitors, with IC50 values in the micromolar to low-nanomolar range. A structure,activity-relationship (SAR) study highlighted lipophilicity as an important property modulating the MAO-B inhibition potency of 7-substituted coumarins, as shown by a linear correlation (n=20, r2=0.72) between pIC50 and calculated log P values. The stability of ester-containing coumarin derivatives in rat plasma provided information on factors that either favor (lipophilicity) or decrease (steric hindrance) esterase-catalyzed hydrolysis. Two compounds (14 and 22) were selected to investigate how lipophilicity and enzymatic stability may affect in vivo MAO activities, as assayed ex vivo in rat. The most-potent and -selective MAO-B inhibitor 22 (=7-[(3,4-difluorobenzyl)oxy]-3,4-dimethyl-1-benzopyran-2(2H)-one) within the examined series significantly inhibited (>60%) ex vivo rat-liver and striatal MAO-B activities 1,h after intraperitoneal administration of high doses (100 and 300,,mol kg,1), revealing its ability to cross the blood,brain barrier. At the same doses, liver and striatum MAO-A was less inhibited in vivo, somehow reflecting MAO-B selectivity, as assessed in vitro. In contrast, the metabolically less stable derivative 14, bearing an isopropyl ester in the lateral chain, had a weak effect on hepatic MAO-B activity in vivo, and none on striatal MAO-B, but, surprisingly, displayed inhibitory effects on MAO-A in both peripheral and brain tissues. [source]