96-77-5Relevant academic research and scientific papers
NMR Characterization of Sulfonation Products of Phenylchloroformate with Verification of NOE Effects by Molecular Modeling
Kwoh, David,Kerschner, Judith L.,Jensen, Arnold,Cece, Anthony
, p. 407 - 412 (1995)
In the trial scale-up of the sulfonation of phenylchloroformate and subsequent formation of sulfonated phenyl carbonates, samples from the batch process showed a number of unexpected by-products.Because they were suspected to have an unusual ring substitution pattern, phenylchloroformate sulfonation was studied by 1H and two-dimensional nuclear magnetic resonance (NMR) techniques.Distance geometry was used to compute internuclear distances, which were used to substantiate the observation of the nuclear Overhauser effect.The reaction mechanism leading to these by-products is proposed.Index Headings: Phenylchloroformate; Sulfonation; 1H NMR; Two-dimensional NMR; Potential energy computation.
A fluorescent molecule based on 1,8- naphthalic anhydride: Synthesis, spectral properties, and studying the conductance in solution
Al-Aqar, Roza
, p. 4227 - 4233 (2020/12/09)
In this paper, the compound of (4-bromo-3-nitro-1,8 -naphthalic anhydride) and the dopant material (4-hydroxy-m-benzene-disulfonic acid) were synthesized. The UV- Vis absorption and emission spectra of the compound were recorded. 4-bromo-1,8- naphthalic anhydride was used as a starting material to prepare the compound (4-bromo-3-nitro-1,8 -naphthalic anhydride) in the presence of concentrated sulphuric acid and sodium nitrate. The dopant material (4-hydroxy-m-benzene-disulfonic acid) was prepared by using phenol in concentrated sulfuric acid. The absorption bands depend on the solvent polarity, which the compound shows significant red shift in DMSO solvent compared to in ethanol solvent. The fluorescence spectra of this compound were sensitive to the solvent polarity, the calculated result indicates that the maximum peak is shifted to red in polar solvent, to the excited states of the polar ICT, which leads to decrease the energy of the excited states. The effect of the dopant material on the conductivities (ionic and specific) of the compound was studied, the ionic conductance was increased as the weight of the dopant material increases.
THE DESULFONATION OF PHENOLSULFONIC ACIDS IN AQUEOUS SODIUM HYDROGEN SULFATE MIXTURES
Jason, Mark E.
, p. 55 - 64 (2007/10/02)
Phenol and phenolsulfonic acids are rapidly sulfonated and desulfonated in aqueous sodium hydrogen sulfate, with or without added sulfuric acid.At temperatures above 130 deg C, desulfonation competes with sulfonation sufficiently to allow steam stripping of phenol from the reaction mixtures, even under conditions of low water content.Above 170 deg C removal of phenol is less efficient because the water content is very low and the predominant species in the reaction mixture is 2,4,6-phenoltrisulfonate.Key words: Phenol; phenolsulfonic acid sulfonation; desulfonation; sodium hydrogen sulfate; kinetics; HPLC.
On the intermediacy of phenyl hydrogen sulfates in the sulfonation of phenols. Sulfonation of phenol, anisole, methyl phenyl sulfate, the 2-halogenophenols, a series of phenyl methanesulfonates together with 2,6-dimethylaniline and its N-methylsulfonyl derivative
de Wit, Peter,Woldhuis, Alex F.,Cerfontain, Hans
, p. 668 - 675 (2007/10/02)
The sulfonation of methyl phenyl sulfate (4) with concentrated aqueous sulfuric acid at 25 deg C yields the 4-sulfonic acid.This initial product then decomposes to give phenol-4-sulfonic acid, which is subsequently sulfonated to phenol-2,4-disulfonic acid.From the first-order-rate coefficients obtained for sulfonation of phenyl methanesulfonate (3) and (4) in 93,2percent H2SO4, for which acid concentration the sulfonating entity is H2S2O7, the ?p+ values of the OSO2Me and OSO2OMe substituents have been determined to be 0.40 and 0.46, respectively.The sulfonation of both 2-chlorophenyl (10) and 2-methylphenyl methanesulfonate (14) with 2.0 equiv of SO3 in nitromethane at 0.0 deg C yields the 4-sulfonic acid as the exclusive product, whereas 2-methoxyphenyl methanesulfonate (13), under the same conditions, forms exclusively the 5-sulfonic acid. 2-Chloro- (6), 2-bromo- (7) and 2-iodophenol (8) with 1.0 and 4.0 equiv of SO3 in nitromethane yield exclusively the 4-sulfonic acid, while 2-fluorophenol (5) with 2.0 and 5.0 equiv of SO3 yields in addition the 5-sulfonic acid to the extent of 4 and 30percent, respectively.In the reactions of 2,6-dimethylphenol (15) and 2,6-dimethylaniline (17) with at least 1 equiv of SO3 in nitromethane, the 3-SO3H/4-SO3H ratio was found to increase on increasing the relative amount of SO3.For both 15 and 17, the limiting 3-SO3H/4-SO3H ratio at high SO3/ArOH ratios is 86/14 and this value is considered to be the ratio for the sulfonation of both 2,6-dimethylphenyl hydrogen sulfate and 2,6-dimethylaniline-N-sulfonic acid.This assumption is supported by the observation that the sulfonation of 2,6-dimethylphenyl methanesulfonate (16) and N-(methylsulfonyl)-2,6-dimethylaniline (18) with SO3 leads to a similar 3-SO3H/4-SO3H ratio.
Aromatic Sulphonation. Part 91. The Sulphonation of Anisole, Phenol, Phenyl Methanesulphonate, Potassium Phenyl Sulphate, and a Series of Methyl-, Bromo-, and Chloro-substituted Anisoles and Phenols in Concentrated Aqueous Sulphuric Acid
Cerfontain, Hans,Lambrechts, Hans J. A.,Schaasberg-Nienhuis, Zwaan R. H.,Coombes, Robert G.,Hadjigeorgiou, Panicos,Tucker, Geoffrey
, p. 659 - 668 (2007/10/02)
The (homogeneous) sulphonation of a number of aromatic ethers and alcohols, viz. anisole (1), 3-methyl- (2), 4-methyl- (3), 2-bromo- (4), 4-bromo- (5), 2-chloro- (6), and 4-chloro-anisole (7), phenol (8), 2-methyl- (9), 3-methyl- (10), 4-methyl- (11), 4-bromo- (12), 2-chloro- (13), and 4-chloro-phenol (14), phenyl methanesulphonate (15), and potassium phenyl sulphate (16) in concentrated aqueous sulphuric acid at 25.0 deg C has been studied, and rates and isomer distributions have been determined.The sulphonation is first-order in the aromatic substrate, and from the rate measurements it is concluded that the species undergoing sulphonation in the phenyl ring is an unprotonated substrate species.In the lower acid concentrations the sulphonating entity is H3SO4(1+).With increasing sulphuric acid concentration there is a gradual change-over in the sulphonating entity from H3SO4(1+) to H2S2O7.The acid concentrations of equal rate contribution by the two entities for anisole and phenol are 87 and 90 +/- 1percent, respectively.Sulphonation on the oxygen atom (i.e., sulphation) does not occur.The o/p-ratios for (1) and (8) do not vary over the studied sulphuric acid range of 75-90percent H2SO4.Partial rate factors for the 2- and 4-position of (1) and (8) are reported.The very low partial rate factors for the 4-substitution of (1) and (8) and the observed extreme suppression and compression of the reactivities of the substrates (1)-(14) are ascribed to hydrogen bonding of the substrates with the acidic solvent species present.It is tentatively suggested that the relatively high contents of sulphonation ortho to -OR with anisole (36percent) and phenol (48percent) are due to specific complexation of the substrates with the sulphonating electrophile.
Aromatic Sulfonation. Part 94. Sulphonation and Sulphation of the Three 2- and 4-Hydroxy- and 2- and 4-Methoxy-benzenesulphonic Acids in Concentrated Sulphuric Acid
Koeberg-Telder, Ankie,Lambrechts, Hans J. A.,Cerfontain, Hans
, p. 1241 - 1246 (2007/10/02)
The sulphonation of 2-methoxy- (1) and 4-methoxy-benzene sulphonate (2) and 1- (3), 3- (4), and 4-hydroxybenzenesulphonate (5) in 86.9-98.5percent H2SO4 at 25 deg C has been studied.Substrates (1)-(3) and (5) all yield the corresponding 2,4-disulphonic acid as the exclusive product, whereas (4) yields a mixture of 2-hydroxybenzene-1,4- and 4-hydroxybenzene-1,2disulphonic acid. 3- and 4-Hydroxy-benzenesulphonic acids in sulphuric acid (>87percent H2SO4) are present in part as their hydrogen sulphates and the sulphuric acid concentration of 50percent sulphation is 97.5 and 100.5 +/- 0.2percent H2SO4.The sulphonation is first order in the aromatic substrate.From the rate dependence on the sulphuric acid concentration it is concluded that the substrate species undergoing ring sulphonation is the -O3SC6H4OR (R = H; Me) species with H2S2O7 as the sulphonating entity.From the observed proportionality between -O3SC6H4OSO3H>/-O3SC6H4OH> and aSO3 it is concluded that the aromatic species undergoing sulphation is again -O3SC6H4OH.
Aromatic Sulphonation. Part 93. Sulphonation of the Three t-Butylphenols, Four Di-t-butylphenols, and 2,4,6-Tri-t-butylphenol
Lambrechts, Hans J. A.,Mul, John,Cerfontain, Hans
, p. 677 - 682 (2007/10/02)
The (homogeneous) sulphonation of the three t-butyl-phenols, 2,4-, 2,5-, 2,6-, and 3,5-di-t-butylphenol, and 2,4,6-tri-t-butylphenol with a number of sulphonating reagents has been studied, and product compositions have been determined.The formation of the several initial and eventual sulphonation products is explained in terms of sulphodeprotonation, protiode-t-butylation, sulphode-t-butylation, and isomerization, the relative importance of which is discussed for the various substrates. 2- (1) and 4-t-butylphenol (3), 2,4- (4), and 2,6-di-t-butylphenol (6), and 2,4,6-tri-t-butylphenol (8) in 98.5percent H2SO4 at 35 deg C after 10 days of reaction all yield 50 +/- 2percent 4-t-butylphenol-2,6- (9) and 50 +/- 2percent phenol-2,4-disulphonic acid (10).With both (1) and (6) the initial step is a rapid 1,3-shift of the t-butyl group from the 2- to the 4-position.With (1) this is then followed by sulphodeprotonation at the 2- and 6- position and with (6) by protiode-t-butylation at the 6-position followed by sulphodeprotonation at the 2- and 6-position.The formation of (9) from the substrates (3), (4), and (8) and the formation of (10) from (1), (3), (4), (6), and (8) is explained by protiode-t-butylation and subsequent sulphodeprotonation.
