Kinetics of hydrolysis and cyclization of ethyl 2-(aminosulfonyl)benzoate to saccharin
The cyclization of ethyl 2-(aminosulfonyl)benzoate (ASB) to give saccharin was investigated in aqueous solutions at pH between 5.2 and 9.5 and in the temperature range of 296.2-334.2 K. The initial concentration of the reactant was varied between 1.45 × 10-5 and 3.86 × 10-4 M. Ultraviolet spectrosco...
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| Autores principales: | , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00456535_v49_n3_p353_DiLoreto |
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| Sumario: | The cyclization of ethyl 2-(aminosulfonyl)benzoate (ASB) to give saccharin was investigated in aqueous solutions at pH between 5.2 and 9.5 and in the temperature range of 296.2-334.2 K. The initial concentration of the reactant was varied between 1.45 × 10-5 and 3.86 × 10-4 M. Ultraviolet spectroscopy was used to obtain the kinetic data. The reaction is acid catalyzed and follows pseudo-first-order kinetics. The experimental rate constant, kobs, increases with temperature and pH. Its dependence on the temperature and pH is well described by: kobs = k1[OH-] = [(2.52 ± 0.9) × 1016 exp(-20.2 ± 1 kcalmol-1/RT) s-1][OH-] A mechanism is proposed and the half-life of ethyl ASB is calculated. © 2002 Elsevier Science Ltd. All rights reserved. |
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