Benzenes sulphonation

The Schotten-Baumann reaction may also be carried out, using, for example, benzene sulphonyl chloride, CeH,SO,Cl (. e., the acid chloride of benzene sulphonic acid, C H5SOjOH) in place of benzoyl chloride, and similar deri a-tives are obtained. Thus when phenol is dissolved in an excess of 10% sodium hydroxide solution, and then shaken with a small excess of benzene sulphonyl... 

C) AMINO AROMATIC SULPHONIC ACIDS. Sulphanilic or p-amino-benzene sulphonic acid, NH2CJH4SO3H. 

The melting points of a number of sulphonacetamides are —benzene-sulphonic acid, 125° p-toluenesulphonic acid, 137° p-bromobenzene-sulphonic acid, 203° m-nitrobenzenesulphonic acid, 189° p-nitroben-zenesulphonic acid, 192° naphthalene-a-sulphonic acid, 185° and naphthalene-p-sulphonic acid, 146°. 

Benzene- sulphon- amlde /)-Tolu- enesul- phon- amlde Benzal Derivative Plcrate 3-Nltro- phthal- Imlde 2 4- Dinitro- phenyl Derivative Formyl Derivative Phenyl thio- urea... 

Bento amide Benzene- sulphon- amide p-Tolu- enesul- phon- amide Plcrate Formyl Derivative Other Derivatives... 

The value of the second-order rate constant for nitration of benzene-sulphonic acid in anhydrous sulphuric acid varies with the concentration of the aromatic substrate and with that of additives such as nitromethane and sulphuryl chloride. The effect seems to depend on the total concentration of non-electrolyte, moderate values of which (up to about 0-5 mol 1 ) depress the rate constant. More substantial concentrations of non-electrolytes can cause marked rate enhancements in this medium. Added hydrogen sulphate salts or bases such as pyridine... 

In the sulphonation process vaporised benzene is forced through a mist of sulphuric acid at 100-120°C and the benzene sulphonic acid formed is neutralised with soda ash to produce benzene sodium sulphonate. This is fused with a 25-30% excess of caustic soda at 300-400°C. The sodium phenate obtained is treated with sulphuric acid and the phenol produced is distilled with steam (Figure 23.1). 

That the sulphuric. acid act.s in the. ihove in.inner, md not merely as a dehydrating apciit appears not only fioin the form.ation of iniKccl ethers, but al.so fiom the f.ii t that the sulphuric acid m.ay be replaced by phiisphonc, arsenic and benzene sulphonic acids. 

Trehy et al. [5] determined linear alkyl benzene sulphonates in sediments in amounts down to 0.5mg kg-1 using this technique. 

This technique has been used to determine linear alkyl benzene sulphonates in sludges [9, 11]. 

Trehey et al. [9] determined alkyl benzene sulphonates and dialkyltetralin sulphonates in sediments by this technique with a detection limit of 0.5g kg 1. 

Uchiyama [11] applied this method to the determination of fluorescent whitening agents and alkyl benzenesulphonates and also methylene blue active substances in bottom sediment samples taken in a lake. The muds were filtered off with a suction filter and frozen until analyzed. About 20g of wet bottom mud was extracted three times with a methanol-benzene (1 1) mixture. After the solvent was evaporated using a water bath, the residue was dissolved in hot water and this solution used for analysis. Table 10.2 shows the analytical results for methylene blue active substances (MBAS), alkyl benzene-sulphonate (ABS), and fluorescent whitening agent (FWA) in bottom sediments. 

Station no. Methylene blue active substances (bgg 1 dry mud) Alkyl benzene- sulphonate (bg gdry mud) Fluorescent whitening agent (fJg gdry mud)... 

From (IV), chlorosulphonic acid (V) and benzene sulphonic acid (VI) are obtained by the replacement of H by Cl and C6H5 respectively Arguing along similar lines, (VIII) is phosphonic acid and (IX) is fluorophosphonic acid, hence (I) is diethyl chlorophosphonate. Th ... 

Compound (VI) is usually described as benzene sulphonic acid, but it k probably more correctly described as phenylsulphonic acid. Accordingly (X) is described as diethyl methylphosphonate. 

Primary and secondary amines are acylated by acid chlorides and anhydrides, in particular also by the chloride of benzene sulphonic add (p. 192). The preparation of acetanilide has already been described (pp. 125, 128). The acetyl- and benzoyl-derivatives of all the simpler primary amines of the benzene and naphthalene series are known, so that these derivatives can always serve for purposes of identification. 

The ease with which the sulphonic group enters into aromatic compounds depends on the nature of the substituents present, just as it does in nitration. Benzene is rather difficult to sulphonate, toluene and naphthalene are somewhat more easy, phenols and amines very easy. The sulphonation of nitrobenzene or the further sulphonation of the benzene sulphonic acids proceeds with more difficulty, and the action of the sulphuric acid must here be intensified by increasing its S03-content. 

In the preparation of benzenesulphonic acid, diphenylsulphone is produced as a by-product. The benzene sulphonic acid which is first formed itself acts on benzene, just as sulphuric acid does, and water... 

Fig. 46. Determination of molecular weight of poly [ 1 (2-hydroxyethylpyridinium benzene sulphonate methacrylate by extrapolation of (Kc/R0)0=o to zero polymer concentration in aq. KC1 of different molarity141) (a) 0.01 M, (b) 0.02 M, (c) 0.1 M, (d) 3.0 M. The resultant molecular weight is 4.3 x 106...

Orange GS 4-[[4-(phenylamino)phenyl]azo]-benzene-sulphonic acid monosodium salt... 

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