Search results for "Cyclohexanol"
showing 10 items of 32 documents
Chemoselektive mono- und disilyletherbildung aus tertiären und sekundären silanen
1985
Abstract Tertiary and secondary silanes are O-selective. With alcohols the corresponding silyl ethers are formed. Cesium fluoride/imidazole (CsF/Im) is a better activating system than CsF alone. Primary OH groups are silylated remarkably faster under CsF/Im activation than secondary OH groups. Tertiary alcohols do not react. Primary OH groups are selectively protected also in the presence of secondary OH groups by silanes with bulky ligands such as triisopropylsilane ((i-Pr) 3 SiH ( 4 )). Ketones are neither reduced to silyl ethers nor transformed to silylenol ethers under the conditions employed. Secondary silanes form monosilyl ethers by amine activation; with CsF the formation of disilyl…
CCDC 834321: Experimental Crystal Structure Determination
2011
Related Article: R.Outouch, B.Boualy, M.A.Ali, L.E.Firdoussi, C.Rizzoli|2011|Acta Crystallogr.,Sect.E:Struct.Rep.Online|67|o1628|doi:10.1107/S1600536811021714
CCDC 647577: Experimental Crystal Structure Determination
2007
Related Article: A.Valkonen, R.Kauppinen, E.Kolehmainen|2007|Acta Crystallogr.,Sect.E:Struct.Rep.Online|63|o2461|doi:10.1107/S1600536807016650
CCDC 916954: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
Development of antimigraine transdermal delivery systems of pizotifen malate.
2015
Abstract The aim of this study was to develop and evaluate a transdermal delivery system of pizotifen malate. Pizotifen is frequently used in the preventive treatment of migraine, but is also indicated in eating disorders. In the course of the project, the effects of chemical enhancers such as ethanol, 1,8-cineole, limonene, azone and different fatty acids (decanoic, decenoic, dodecanoic, linoleic and oleic acids) were determined, first using a pizotifen solution. Steady state flux, diffusion and partition parameters were estimated by fitting the Scheuplein equation to the data obtained. Among the chemical enhancers studied, decenoic acid showed the highest enhancement activity, which seeme…
An overview of the clinical efficacy of mirtazapine
2002
Mirtazapine is at least as effective as the tricyclic antidepressants and trazodone in a wide range of patient subgroups including in- and out-patients with moderate to severe depression. It also appears to be at least as effective as the serotonin and noradrenaline reuptake inhibitor venlafaxine in the treatment of severely depressed melancholic patients. When compared with the selective serotonin reuptake inhibitors (SSRIs), mirtazapine shows a significantly earlier onset of action. Further analysis of a study comparing mirtazapine with the SSRI paroxetine indicated that early improvement was a highly sensitive predictor of later stable response for both drugs. The positive predictive val…
Cytotoxic activity of secondary metabolites derived from Artemisia annua L. towards cancer cells in comparison to its designated active constituent a…
2010
Artemisia annua L. (sweet wormwood, qinhao) has traditionally been used in Chinese medicine. The isolation of artemisinin from Artemisia annua and its worldwide accepted application in malaria therapy is one of the showcase success stories of phytomedicine during the past decades. Artemisinin-type compounds are also active towards other protozoal or viral diseases as well as cancer cells in vitro and in vivo. Nowadays, Artemisia annua tea is used as a self-reliant treatment in developing countries. The unsupervised use of Artemisia annua tea has been criticized to foster the development of artemisinin resistance in malaria and cancer due to insufficient artemisinin amounts in the plant as c…
Enantioselective Protonation of the Lithium Transient Enolate of2-Methyltetralone with 2-Sulfinyl Alcohols
2005
A new catalytic cycle for the enantioselective protonation of cyclic ketone enolates with sulfinyl alcohols has been developed. An enol trifluoroacetate that can be easily obtained from the corresponding ketone is used for the first time as an enolate precursor of a cyclic ketone enolate. In this method, the achiral alcohol plays two roles: it is involved, as is usual in catalytic asymmetric protonation reactions, in the turnover of the chiral proton source and also in the generation of a transient enolate through the reaction of its corresponding alkoxide with the enol trifluoroacetate precursor. Stereoselectivity is highly dependent on the structure of the achiral alcohol. High levels of …
Über die synthese von oligophenylenes mit einer o-verknüpfung. 10. Mitteilung
1960
Es werden zwei Wege zur Darstellung von Oligophenylenen mit einer o-Winkelung beschrieben. Als Ausgangssubstanzen dienen der Mono-enolather des Cyclohexandion (1,2) bzw. Cyclohexenoxyd. Die Darstellung des Mono-enolathylathers des Cyclohexandion (1,2) wird beschrieben. Durch Oxydation nach OPPENAUER mit Chinon als Wasserstoffacceptor konnen die als Zwischenprodukte der Oligophenylene erhaltenen Cyclohexanolderivate in 90%iger Ausbeute in die benotigten Ketone ubergefuhrt werden. Folgende o-gewinkelten Oligophenylene wurden synthetisiert : o-Terphenyl; 2o2-Quater-phenyl ; 32, 43-Dimethyl-2o2-quaterphenyl ; 3o2-Quinquiphenyl ; 12, 23-Dimethyl-3o2-quinquiphenyl ; 12, 23, 42, 53-Tetramethyl-3o2…
Über den einfluß des lösungsmittels beim thermischen zerfall des azoisobuttersäuredinitrils
1967
Der Zerfall des Azoisobuttersauredinitrils wurde in 10 verschiedenen Losungsmitteln kinetisch untersucht. Er ist streng eine Reaktion erster Ordnung. Die Zerfallsgeschwindigkeit ist in den einzelnen Losungsmitteln verschieden. Der maximale Unterschied betragt bei 60°C 40% (Malonsaurediathylester/Cyclohexanol), entsprechend einer Differenz der Freien Enthalpie des Ubergangszustandes von 250 cal/Mol. Die starkeren Anderungen der Aktivierungsenthalpie bis zu 1,5 kcal/Mol werden durch entsprechende Anderungen der Entropie des Ubergangszustandes kompensiert. The thermal decomposition of azo-bis-isobutyronitrile in a series of 10 solvents was investigated. The reaction is strictly of first order.…