22033-07-4Relevant articles and documents
Sustainable access to sulfonic acids from halides and thiourea dioxide with air
Zhang, Hui,Wang, Ming,Jiang, Xuefeng
supporting information, p. 8238 - 8242 (2020/12/29)
A sustainable and mild one-step strategy is explored for the synthesis of aryl and alkyl sulfonic acids using a facile combination of halides and sulfur dioxide surrogates under air. The cheap industrial material thiourea dioxide was employed as an eco-friendly and easy-handling sulfur dioxide surrogate, while air was used as a green oxidant. Both aryl and alkyl sulfonic acids were obtained under transition metal-catalyzed or transition metal-free conditions. Mechanistic studies demonstrated that sulfinate was involved as an intermediate in this transformation. Notably, this protocol has been applied to the late-stage sulfonation of the drugs naproxen, isoxepac and ibuprofen.
Acid-catalyzed hydrolysis of benzenesulfonamides. Rate enhancements by ortho-alkyl substituents
Wagenaar, Anno,Kirby, Anthony J.,Engberts, Jan B. F. N.
, p. 203 - 205 (2007/10/02)
Pseudo-first-order rate constants have been measured for the acid-catalyzed hydrolysis of a series of N,N-dimethyl- and N-methyl-N-phenylbenzenesulfonamides in 70 percent (v/v) CF3CO2H/H2O at 99 deg C.Analysis of the effect of the alkyl substituents in the benzene ring shows a remarkable rate enhancement by ortho-alkyl groups, in the contrast with a rate retardation of similar substituents in the corresponding benzamides.The rate enhancement in the sulfonamides is attributed to relief of initalstate strain in the transition state for hydrolysis.When the sulfonamide moiety is contained in a five-membered ring fused to a phenyl ring, the rate of hydrolysis is markedly reduced by an ortho-methyl substituent.
SULFONATION OF CUMENE WITH SULFURIC AND HALOGENOSULFONIC ACIDS
Krylov, E.N.,Odintsova, G.N.
, p. 1695 - 1701 (2007/10/02)
The sulfonation of cumene by sulfuric and chloro- and fluorosulfonic acids in the range of 0-100 deg C under heterogenous and heterogenous-homogenous conditions gives mixtures of isomeric sulfonyl halides and/or sulfonic acids, in which the para isomer predominates (90-95percent of the total isomers at temperatures above 75 deg C and/or with the addition of the sulfonating agent to the cumene).If the reagents are mixed in the opposite order and at low temperatures (0-25 deg C), the proportion of the ortho isomer in the mixture of sulfo products increases to 20-22percent.The yield of the sulfonyl halides show an extremal relationship with temperature.The composition of the sulfonic acids and their halides formed under the conditions of a single experiment with the halogenosulfonic acids differ as a result, probably, of the nonequilibrium nature of the process and of the presence of several paths to the formation of the acid halides.
