- On the positional reactivity order in the sulfur trioxide sulfonation of benzene, halogenobenzenes, halogenonaphthalenes, and chloroanthracenes
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The reaction of sulfur trioxide with benzene, the four halogenobenzenes, and six halogenonaphthalenes in dichloromethane as solvent, and with four chlorinated anthracenes in nitromethane as solvent, has been studied by analysis of the resulting mixture of the sulfo derivatives with 1H NMR. The sulfonation of benzene yields initially benzenesulfonic acid and subsequently the 1,3-disulfonic acid (1,3-S2). The initial sulfonation of the four halogenobenzenes yields ? 98% of the 4-S. Their subsequent sulfonation gives the 2,4-S2 and in the case of fluoro- and iodobenzene also the 2,4,6-S3. Monosulfonation of 1-fluoronaphthalene yields only the 4-S, whereas the three other 1-halogenonapthalenese yield in addition some 5-S. Further sulfonation on any of the four 1-halogenonaphthalene-4-sulfonic acids yields a mixture of the 2,4-S2 and 4,7-S2, and eventually also some 2,4,7-S3, whereas the 1-halogeno-5-sulfonic acids give the corresponding 5,7-S2. Sulfonation of 2-chloro- and 2-bromonaphthalene yields initially 85% 8-S and 15% 4-S, which are subsequently converted into the 6,8-S2 and 4,7-S2, respectively. On reaction with 1.0 mol-equiv. of SO3, 2-chloroanthracene gives the 9-S, and 9-chloroanthracene gives an 18:82 mixture of the 4-S and 10-S. Both 1,5- and 1,8-dichloroanthracene yield initially the 4-S and subsequently the 4,8-S2 and 4,5-S2, respectively.
- Cerfontain,Zou,Bakker,van de Griendt
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p. 1966 - 1971
(2007/10/02)
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- Methyl Transfers. 8. The Marcus Equation and Transfer between Arenesulfonates
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Using a 35S label, rates of identity methyl-transfer reactions XC6H4*SO3(1-) + CH3O3SC6H4X -> XC6H4*SO3CH3 + XC6H4SO3(1-) in sulfolane have been measured.For all five cases, these identity rates fit the Hammett equation with the rather large ρ of +0.6.Rates and equilibria for XC6H5SO3Me + 3,4-Cl2C6H3SO3(1-) have been measured.The fit to the Marcus equation using averages of the experimental identity rates for the intrinsic rate is perfect, within experimental error.The absolute values of ρ for the forward and reverse reactions differ by an amount quantitatively consistent with the nonzero identity reaction ρ.The significance of the identity reaction ρ > 0 is discussed.
- Lewis, Edward S.,Hu, Daniel D.
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p. 3292 - 3296
(2007/10/02)
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- SENSITIZED PHOTO-OXIDATION OF THIOPHENOLATES A SINGLET OXYGEN REACTION
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Tetraphenylporphyrin-sensitized photo-oxidation of thiophenolates leads to the corresponding benzenesulfonates.The reaction proceeds via attack of singlet oxygen on the thiophenolate anion.A reaction mechanism is proposed.
- Jongsma, Simon J.,Cornelisse, Jan
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p. 2919 - 2922
(2007/10/02)
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