- NITRATION OF AROMATIC COMPOUNDS
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The present invention provides a process for nitrating aromatic compounds without the need for a solid catalyst and/or any organic solvents and/or any other additives. A typical process includes combining or admixing a nitric acid and an anhydride compound under conditions sufficient to produce a reactive intermediate. The aromatic compound to be nitrated is then added to this reactive intermediate to produce a nitroaromatic compound. The nitroaromatic compound can be substituted with one or more, typically, one to three, and often one or two nitrate (-NO2) groups.
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Paragraph 0049
(2016/08/17)
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- Regioselective dinitration of simple aromatics over zeolite Hβ/nitric acid/acid anhydride systems
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Various nitration systems comprising nitric acid, acid anhydride and zeolite H£] in the absence of solvent are described. Direct double nitration of toluene with a nitric acid, propanoic anhydride and zeolite Hβ system has been developed to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of 123:1. This system also nitrates activated mono-substituted benzenes (anisole and phenetole) and moderately activated mono-substituted benzenes (ethylbenzene and propylbenzene) to give mainly 2,4-dinitro derivatives. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used. ARKAT-USA, Inc.
- Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
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p. 107 - 123
(2014/04/17)
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- Highly regioselective dinitration of toluene over reusable zeolite Hβ
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A nitration system comprising nitric acid, propanoic anhydride, and zeolite Hβ has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4-dinitration of toluene; the catalyst is reusable, solvent is not needed, and an aqueous work-up is not required.
- Smith, Keith,Alotaibi, Mohammad Hayal,El-Hiti, Gamal A.
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p. 244 - 247
(2013/02/22)
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- METHODS FOR THE NITRATION OF AROMATIC COMPOUNDS
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According to the invention there is provided a method for the nitration of an aromatic compound including the step of reacting the aromatic compound with nitric acid in the presence of an acid anhydride and an aluminosilicate catalyst, in which the acid anhydride is at least one of: ((CnH2n+1)CO)20, where n is 1 to 4 and the moiety CnH2n+1 can be straight or branched chain; ((CHpClq)CO)20, where p is 0 to 2, q is 1 to 3, and p+q = 3; and oxoiane -2, 5-dione, with the proviso that when the acid anhydride is (CH3CO)20, the aromatic compound is toluene, 2-nitrotoluene or 4-nitrotoluene, and the nitration is performed to produce 2,4-dinitrotoluene.
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Page/Page column 13
(2012/05/04)
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- PHOSPHODIESTERASE 10 INHIBITORS
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The present invention if directed to certain cinnoline compounds that are PDE10 inhibitors, pharmaceutical compositions containing such compounds and processes for preparing such compounds. The invention is also directed to methods of treating diseases mediated by PDE10 enzyme, such as obesity, non-insulin dependent diabetes, schizophrenia, bipolar disorder, obsessive-compulsive disorder, and the like.
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Page/Page column 56
(2008/06/13)
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- CINNOLINE AND QUINAZOLINE DERIVATES AS PHOSPHODIESTERASE 10 INHIBITORS
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The present invention is directed to cinnoline and quinazoline compounds of formula (I) that are PDE10 inhibitors, pharmaceutical compounds containing the same and processes for preparing the same. The invention is also directed to methods of treating diseases mediated by PDE10 enzyme such as obesity, non-insulin dependent diabetes, schizophrenia or bipolar disorder, obsessive-compulsive disorder, and the like.
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Page/Page column 53
(2010/11/28)
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- Cross-coupling of aryl halides and triflates with intramolecularly stabilized group 13-metal alkylating reagents in the presence of mixed-metal catalysts
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In the presence of tertiary phosphines, the palladium-containing mixed-metal complexes [(CO)4Fe(μ-PPh2)Pd(μ-Cl)]2(1) and [(CO)3Co]2(μ-CO)Pd[μ-(Ph2PCH 2)2] (2) catalyze the cross-coupling of aryl triflates and halides (including chlorides) with intramolecularly stabilized dialkylaluminum, -gallium and -indium reagents 3-8. The reactions are high yielding, and homocoupling and hydrodehalogenation processes are minimal even when the alkyl moieties of the alkylating reagents contain β-hydrogen atoms. As the components of the mixed-metal complexes are either poor catalysts, or completely inactive, the high catalytic activity of 1 and 2 is attributed to synergism between the different metal nuclei of the catalysts.
- Shenglof, Margarita,Gelman, Dmitri,Heymer, Bernd,Schumann, Herbert,Molander, Gary A.,Blum, Jochanan
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p. 302 - 306
(2007/10/03)
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- Palladium-catalyzed cross-methylation of aryl chlorides by stabilized dimethylaluminium and -gallium reagents
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Two methods for palladium-catalyzed cross-methylation of aryl chlorides by intramolecularly stabilized dialkylaluminium and -gallium complexes 6-13 have been studied. In one method, in which either tetrakis(triphenylphosphine)palladium (1) or dichloro- bis(triphenylphosphine)palladium (2) is used as the catalyst at 80-90°C, the activation of the chlorine atom is affected by introduction of strong electron-withdrawing groups into the aromatic moiety. The second method is based on the application of either [1,3- bis(diisopropylphosphino)propane)]palladium (4) or homologous electron-rich palladium complexes as catalysts. Although 4 promotes smooth cross-alkylation of aryl chlorides it fails to activate simple aryl bromides.
- Blum, Jochanan,Berlin, Olga,Milstein, David,Ben-David, Yehoshua,Wassermann, Birgit C.,Schutte, Stefan,Schumann, Herbert
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p. 571 - 575
(2007/10/03)
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