10234-03-4Relevant academic research and scientific papers
Sulfonation of anisole, phenol, toluene and related alkyl and alkoxy derivatives with SO3. The influence of the solvent system on the reactivity and the sulfonic acid product distribution
Ansink, Harold R. W.,Cerfontain, Hans
, p. 183 - 187 (2007/10/02)
The reactions of anisole (1), phenol (2), the alkoxy- and alkylphenyl ethers 3-11, toluene (12) and the o-dialkylbenzenes 13-15 with sulfur trioxide in dichloromethane or trichlorofluoromethane have been studied.Our results have been compared with those obtained with the same substrates upon reaction with SO3 in nitromethane and dioxane.We show that ortho substitution is enhanced for sterically unhindered phenyl ethers and phenols due to complex formation between SO3 and the C(sp2)-bonded oxygen when dichloromethane is used as solvent instead of nitromethane or dioxane.This is mainly as a result of intramolecular SO3 transfer from the oxygen to the ortho carbon and subsequent conversion of the resulting ?-complex into the ortho sulfonic acid.
Methyl Transfers. 8. The Marcus Equation and Transfer between Arenesulfonates
Lewis, Edward S.,Hu, Daniel D.
, p. 3292 - 3296 (2007/10/02)
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.
Solutes in sulfuric acid. Part VIII. Protonation of phenol, 4-fluorophenol and the 2- and 4-sulfonates of anisole and phenol in concentrated aqueous sulfuric acid; determination of pKa values by means of 13C NMR
Koeberg-Telder, Ankie,Lambrechts, Hans J. A.,Cerfontain, Hans
, p. 293 - 298 (2007/10/02)
The protonation of phenol (2), 4-fluorophenol (3), phenyl methanesulfonate, potassium phenyl sulfate and the potassium 2- and -4-sulfonates of both phenol and anisole in concentrated aqueous sulfuric acid at 30 deg C has been investigated using 13C NMR spectroscopy.The results show that phenol and 4-fluorophenol are protonated predominantly on the oxygen atom.This protonation is governed by the Hoa acidity function.The pKa of the oxonium ions of 2 and 3 are -6.40 +/- 0.05 and -6.41 +/- 0.05, respectively.The protonation of phenyl methanesulfonate occurs at acid concentrations > 100percent.Potassium phenyl sulfate in >/= 20percent H2SO4 hydrolyses very rapidly to give phenol.The 2- and 4-sulfonates of both phenol and anisole are protonated on both the -OR (R = H, Me) and the SO3- groups; the sulfuric acid concentrations of half-protonation have been determined to be between 80.0 and 83.3percent H2SO4, corresponding with pKa's of the conjugate acids between -6.34 and -6.66 based on the Hoa scale.
SENSITIZED PHOTO-OXIDATION OF THIOPHENOLATES A SINGLET OXYGEN REACTION
Jongsma, Simon J.,Cornelisse, Jan
, p. 2919 - 2922 (2007/10/02)
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.
