|
| ||
|
|
||
Acid Isopropyl Ester (acid + isopropyl_ester)
Selected AbstractsComparative Reactivity of Hypervalent Iodine Oxidants in Metalloporphyrin-Catalyzed Oxygenation of Hydrocarbons: Iodosylbenzene Sulfate and 2-Iodylbenzoic Acid Ester as Safe and Convenient Alternatives to IodosylbenzeneADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009Abstract 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-oneJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2006Jarle 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 1A2JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2001Peter 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 complicationsMOVEMENT DISORDERS, Issue 3 2003Frédéric 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] | |||||||||||||