- Cyanodibenzo[1,4]dioxines: A new family of synthons for substituted dibenzo[1,4]dioxines
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Cyanodibenzo[1,4]dioxines, previously unreported, are prepared quantitatively from catechols by nucleophilic fluorodisplacement from 2,3- and 3,4-difluorobenzonitriles, involving meta-fluorodisplacement, in DMF at 130 °C in the presence of potassium carbonate; the cyano-substituted dioxines can be transformed to other substituted dibenzo[1,4]dioxines.
- Eastmond, Geoffrey C.,Paprotny, Jerzy
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- METHODS OF TREATING LIVER FIBROSIS USING CALPAIN INHIBITORS
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Disclosed herein are methods of treating liver fibrosis by administering calpain inhibitors to subjects in need thereof.
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Paragraph 0180
(2020/01/24)
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- CALPAIN MODULATORS AND THERAPEUTIC USES THEREOF
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Small molecule calpain modulator compositions and pharmaceutical compositions can be prepared and used as therapeutic agents. Exemplary compositions include non-macrocyclic a-keto amide derivatives. The therarapeutic agents can be used for treating fibrot
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Paragraph 0238
(2019/01/10)
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- Synthesis of cyanodibenzo[1,4]dioxines and their derivatives by cyano-activated fluoro displacement reactions
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A new group of cyanodibenzo[1,4]dioxines have been synthesized by cyano-activated fluoro displacement reactions between cyanodifluorobenzenes and catechols in DMF at 130°C in the presence of potassium carbonate. This route is exemplified by the synthesis of cyanodibenzo[1,4]dioxines from several substituted catechols. The reactions are virtually quantitative. Cyanodibenzo[1,4]dioxines were hydrolysed with potassium hydroxide in ethylene glycol or converted into amide derivatives to yield additional substituted dibenzo[1,4]dioxines. Cyanodibenzo[1,4]-dioxines are fluorescent and excitation and emission data are presented. Improved syntheses of 4,5-diphenyl-veratrole and 3,6-dimethylcatechol, the latter involving reduction of a phenolic Mannich base at atmospheric pressure, have been elaborated.
- Eastmond,Paprotny,Steiner,Swanson
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p. 379 - 384
(2007/10/03)
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- Syntheses of dibenzodioxin derivatives via iron complexes, and further functionalizations via directed metallation
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Double nucleophilic aromatic substitution reactions between (cyclopentadienyl)(η6-1,2-dichlorobenzene)iron(1 +) salts and substituted 1,2-benzenediols have been carried out under mild conditions to prepare 6-dibenzodioxin>iron(1 +) complexes functionalized in the 1- or 2-position with an alkyl, aldehyde, carboxylic acid, methoxycarbonyl, carboxamide, or hydroxy group. 3-Methyl- and 4-methyl-(η6-1,2-dichlorobenzene)iron complexes were treated with substituted 1,2-benzenediols to effect functionalization of both aromatic rings of the heterocycle.The dibenzodioxin ligands were liberated routinely by irradiation with ultraviolet light.Directed deprotonation of the free functionalized dibenzodioxins with an alkyllithium reagent followed by quenching with a variety of electrophiles yielded further derivatives, including two new isoindolone systems.
- Cambie, Richard C.,Janssen, Sally J.,Rutledge, Peter S.,Woodgate, Paul D.
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p. 387 - 418
(2007/10/02)
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- An Improved Synthesis of Substituted Dibenzodioxines
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An improved general synthesis of substituted dibenzodioxines by reaction of catechol and substituted 1,2-dichloro- or 2-chloronitro-benzenes with metallic potassium in hexamethylphosphoramide is reported.The yields are generally superior to those in published methods, and in particular the reaction appears the one of choice for the synthesis of both the parent dibenzodioxine and the 1-carboxy derivative.
- Lee, Ho H.,Denny, William A.
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p. 1071 - 1074
(2007/10/02)
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- Aromatic Lithiation Directed by the Carboxylic Acid Groups. Synthesis of 9-Substituted Dibenzodioxin-1-carboxylic Acids and 6-Substituted Phenoxathiin-4-carboxylic Acids
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An efficient procedure has been developed for the regiospecific synthesis of 9-substituted dibenzodioxin-1-carboxylic acid derivatives.Lithiation of dibenzodioxin-1-carboxylic acid forms the lithium carboxylate, which directs subsequent metalation exclusively to the 9-position.Conditions for the controlled mono- and dilithiation of dibenzodioxin itself, leading to the direct synthesis of the corresponding mono- and isomeric dimethyl esters, are also described.
- Palmer, Brian D.,Boyd, Maruta,Denny, William A.
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p. 438 - 441
(2007/10/02)
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