- Influence of the aromatic substitutes in the thermal and kinetic behavior of mesoionic compounds of the 1,3-thiazole-5-tiolate system
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In this work, three mesoionic compounds of the 1,3-thiazole-5-tiolat system were studied, derived from amino acids of the glycerin through 1,3-dipolar cyclo-addition/reversion reaction. The mesoionic compounds were characterized as: MI-1 (mesoionic 2-(4-chlorophenyl)-3-methyl-4-phenyl-1,3-thiazole-5-tiolat); MI-2 (mesoionic 2-(4-chlorophenyl)-3-methyl-4-(4-isopropylphenyl)-1,3-thiazole-5-tiolat) and MI-3 (Mesoionic 2-(4-clorophenyl)-3-methyl-4-(methoxyphenyl)-1,3-thiazole-5-tiolate). These compounds were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), thermogravimetry (TG) and differential scanning calorimeter (DSC). Also, the kinetic study of the thermal decomposition by non-isothermal thermogravimetry has been realized, presenting, the kinetic and thermal behavior of these compounds. The results of the spectroscopic analysis confirmed the structure of the synthesized mesoionic compounds. The DSC curves of the mesoionic compounds MI-1, MI-2, and MI-3 indicated the fusion of two of them followed by a subsequent decomposition. The TG/DTG curves showed that the decomposition of the mesoionic compounds MI-1, MI-2 and MI-3 occurred in several steps.
- de Morais, Soraya Alves,da Silva Morais, Crislene Rodrigues,Filho, Petr?nio Filgueiras de Athayde,Lira, Bruno Freitas,Souza, Marcos Antonio feitosa de
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experimental part
p. 598 - 602
(2010/08/21)
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- Synthesis, characterization and crystallographic studies of three 2-aryl-3-methyl-4-aryl-1,3-thiazolium-5-thiolates
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Mesoionic 2,4-diphenyl-3-methyl-1,3-thiazolium-5-thiolate, 2-(4′-chlorophenyl)-3-methyl-4-phenyl-1,3-thiazolium-5-thiolate and 2-(4′-chlorophenyl)-3-methyl-4-(4′-isopropyl-phenyl)-1,3- thiazolium-5-thiolate were synthesized via N-methyl-C-aryl-glycines, i
- De Athayde-Filho, Petronio Filgueiras,Miller, Joseph,Simas, Alfredo Mayall,Lira, Bruno Freitas,De Souza Luis, José Alixandre,Zuckerman-Schpector, Júlio
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p. 685 - 690
(2007/10/03)
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- Tandem 1,3-dipolar cycloadditions of muenchnones. Syntheses and molecular structures of 10-azatetracyclo[6.3.0.04,11.05,9]undecanes and azahomopentaprismane
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Photocyclization of 10-benzyl-9,11-diphenyl-10-azatetracyclo[6.3.0.04,11.0 5,9]undeca-2,6-diene 11, prepared in one step from muenchnone 7 and cycloocta-1,3,5,7-tetraene 10, gives azahomopentaprismane 12.
- Gribble, Gordon W.,Sponholtz III, William R.,Switzer, Frank L.,D'Amato, Ferdinando J.,Byrn, Marianne P.
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p. 993 - 994
(2007/10/03)
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- PHOTOCHEMICAL AND THERMAL REACTIONS OF HETEROCYCLES. IV. PHOTO-OXIDATION REACTIONS OF MESOIONIC DITHIOLIUMOLATE, THIAZOLIUMOLATE, AND RELATED HETEROCYCLES. SOLVENT EFFECTS ON THE COURSE OF THE PHOTO-OXIDATION
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Photo-oxidation of mesoionic 1,3-dithiolium-4-olates (1) gave diacyl disulfide (2), and that of a mesoionic thiazolium-4-olate (6) and oxazolium-5-olate (9) gave diacylamides as the main products.The formation of these products was rationalized by a route involving fragmentation of the corresponding endoperoxides, which are formed by cycloaddition of singlet oxygen on the mesoionic rings.Photo-oxidation of 5(4H)-oxazolones (12) and a 5(4H)-thiazolone (17) in dichloromethane gave the corresponding dehydro-dimers, while that of the former in dimethylformamide gave mainly diacylamides.The acylamides were considered to arise via the endoperoxides of the mesoionic tautomers.
- Kato, Hiroshi,Tani, Kazue,Kurumisawa, Haruki,Tamura, Yoshiko
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p. 1313 - 1322
(2007/10/02)
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