- Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XIII. Sulfur Inversion in 9,9-Dilakyl-10-mesitylthioxanthenium Salts
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The sulfur-inversion in the title compound (alkyl=ethyl) was found to take place with the following activation parameters by dynamic NMR spectroscopy: ΔH(act)=23.8+/-0.2 kcal mol-1, ΔS(act)=2.6+/-0.4 cal mol-1 K-1.The significance of the near zero entropy of activation is discussed.The mesityl group in the title compounds also showed restricted rotation of which barrier to rotation was estimated to be 14 kcal mol-1 at 318 K fo the compound where the alkyl is a methyl.
- Oki, Michinori,Yamada, Yasuhisa
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- REAGENT FOR ENHANCING GENERATION OF CHEMICAL SPECIES
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A reagent that enhances acid generation of a photoacid generator and composition containing such a reagent is described.
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Paragraph 0071
(2015/04/15)
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- A facile general synthesis of 9-position functionalised heteroniumanthracene salts
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Heteroniumanthracenes react selectively as the cations (1a) or as the corresponding carbinol bases (9b,c) with benzotriazole to give the corresponding 9H-(benzotriazol-1-yl)heterocycles (10a-c). As novel heterocyclic anion precursors, (10a-c) undergo smoo
- Katritzky, Alan R.,Denisenko, Sergey N.,Czerney, Peter
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p. 2413 - 2423
(2007/10/03)
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- Facile synthesis of 1,2-diaryl- and triarylethenes with supported fluoride bases
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Differently substituted arenecarbaldehydes, mainly benzaldehydes, can be very efficiently condensed with a wide variety of methylbenzenes having an electron-withdrawing group in the para-position, as well as with fluorenes, xanthene, cyclopentadienes and indenes by using a standardized KF- or CsF-Al2O3 base system in dimethylformamide.
- Hellwinkel,Goke,Karle
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p. 973 - 978
(2007/10/02)
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- TRICYCLIC NEUROLEPTICS: SYNTHESIS OF METABOLITES OF ISOFLOXYTHEPIN AND SOME RELATED COMPOUNDS
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The isofloxythepin(I) metabolite IV was synthesized via the acids IX and XI and the esters X and XII.The enamine VIII was prepared from 3-fluoro-8-(2-propyl)dibenzothiepin-10(11H)-one by two methods and was reduced to I.Cloflumide (II) was obtained by reaction of 2,10-dichloro-7-fluoro-10,11-dihydrodibenzothiepin with 3-(1-piperazinyl)propionamide and was oxidized to the sulfoxide XVI.The unsaturated analogue XVII of clopithepin (III) was prepared from 2-chlorodibenzothiepin-10(11H)-one by reaction with 2-bromoethanol in the presence of 4-toluenesulfonic acid in boiling benzene and by the following substitution reaction with 2-(1-piperazinyl)ethanol.An improved synthesis of 6-methyldibenzothiepin-10(11H)-one (XIX) was elaborated.The acid XXVII was synthesized and cyclized with polyphosphate ester.A mixture of compounds was formed from which the ketone XXXVI was isolated and processed by reaction with formamide and formic acid at 200 deg C.One of the products was characterized as the formamide XXXIII and was reduced with lithium aluminium hydride to a basic product supposed to be XXXIV.A series of by-products was isolated and characterized.The enamine VIII (VUFB-17156) was found to be a strong neuroleptic agent, similar to isofloxythepin (I).The enol ether XVII (VUFB-17733) was characterized as a mild, practically noncataleptic neuroleptic agent.
- Sindelar, Karel,Jilek, Jiri,Pomykacek, Josef,Valenta, Vladimir,Hrubantova, Marta,et al.
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p. 2282 - 2303
(2007/10/02)
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