- INVESTIGATION IN THE REGION OF THIOSULFONIC ACIDS. XXXII. REACTION OF ARYL ESTERS OF THIOSULFONIC ACIDS WITH SUBSTANCES CONTAINING AN ACTIVE METHYLENE GROUP
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The reactions of the aryl esters of thisulfonic acids with diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and acetylacetone in the presence of sodium alcoholates were investigated at various temperatures.Without heat the reaction takes place with the formation of sulfinates and arenesufenic esters, which form their thio derivatives when heated with substances containing an active methylene group in the presence of sodium alcoholates.It was thus demonstrated that under the investigated conditions thioarylating characteristics are exhibited not by the aryl esters of the thiosulfonic acids but by the esters of arenesufenic acids formed as the initial products of these reactions.
- Boldyrev, B. G.,Aristarkhova, L. N.,Stoyanovskaya, Ya. I.,Bilozor, T. K.
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p. 1160 - 1167
(2007/10/02)
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- Sulphur-oxygen versus carbon-oxygen bond fission in the solvolysis of benzyl sulphenates
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In contrast to p-anisyl trichloromethanesulphenate 1, which readily undergoes ethanolysis at room temperature with carbon-oxygen bond fission, the ethanolysis of the corresponding 2-nitrobenzenesulphenate 2 proceeds at a similar rate only at 100°, and involves sulphur-oxygen bond cleavage. While the solvolysis of 1 showed first-order kinetics, the solvolysis of 2 was second-order (first-order with respect to ester and to added base). The solvolysis rate of 2 decreases on going from 100% to 80% ethanol and by using pyridine instead of acetate as base, consistent with an SN2 type mechanism involving nucleophilic displacement at sulphur by the base or lyate ion. The rate of solvolysis of 1 is greatly enhanced in polar solvents and correlates satisfactorily with the ionization of p-methoxyneophyl tosylate. An ionization mechanism to some ion pair species is suggested for the solvolysis of 1.
- Braverman,Reisman
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p. 3891 - 3896
(2007/10/05)
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