Sulphonation with sulphites

Anthraquinone can be brominated, chlorinated directly to the tetrachloro (I, 4, 5, 8-) stage, nitrated easily in the 1-position, but gives the 1,5-and 1,8-dinitro-derivalives on prolonged nitration the nitro groups in these compounds are easily displaced by neutral solutions of alkali sulphites yielding the corresponding sulphonic acids. Sulphonation with 20-30 % oleum gives the 2- 2,6- and 2,7-derivatives in the presence of Hg the 1- 1,5- and 1,8- derivatives are formed. 

The second stage is sulphonation with sodium sulphite (Figure 4.13) which adds the sulphonate group across the double bond. This, too, is an exothermic reaction and care must be taken to limit the temperature rise to avoid discolouration of the sulphosuccinate. 

Epoxides also react with sulphite, or hydrogen sulphite, to form hydroxy sulphonate... 

NajS 2-aminoanthraquinone with sulphite gives only the 3-sulphonate. The lower selectivity with hydroxyquinones is attributed to partial ionization of the OH group in the reaction medium. 

Ingles, D.L. The formation of sulphonic acids from the reaction of reducing sugars with sulphite, A jf. J. 

Perhaps the most widely utilized su henyl derivatives are the S-sulphonates [160] which can be prepared by oxidative sulphitolysis of a disulphide bond with sodium sulphite and sodium tetrathionate at pH 7-9 [161], by the oxidation of disulphides or thiols with sulphite ion and copper(ll) [160], by the use of small amounts of cysteine together with oxygen and sulphite [162], or by the reaction of halides with sodium... 

This direct sulphonation should be compared with the indirect methods for the preparation of aliphatic sulphonic acids, e.g., oxidation of a thiol (RSH -> RSOjH), and interaction of an alkyl halide with sodium sulphite to give the sodium sulphonate (RBr + Na,SO, -> RSO,Na + NaBr). 

Benzenediazonium chloride reacts in solution with sodium sulphite to give benzenediazonium sodium sulphonate, which when treated with sulphurous acid undergoes reduction to phenylhydrazine sodium sulphonate. The latter readily hydrolyses in the presence of concentrated hydrochloric acid to give... 

Sodium mlphanilate.—Burns with difficulty, leaving a residue of (chiefly) sodium sulphide. Add dil. HCl, and confirm without delay the evolution of HjS by means of a filter-pa per moistened with lead acetate solution. Typical of salts of the sulphonic acids. Acetone sodium bisulphite.—Almost non-inflammable, leaving a colourless residue of sodium sulphite and sulphate. Transfer residue to a test-tube, add dil. HCl, warm, and confirm the SO2 evolved. 

Obtemperanskaya and Kareva25 determined a, /J-unsaturated ketones and sulphones by adding sodium sulphite to the sample in p-dioxan. After 5-10 min they titrated with standard sulphuric acid potentiometrically or to thymolphthalein ... 

Gutfelt et al. (1997) have evaluated various ME formulations as reaction media for synthesis of decyl sulphonate from decylbromide and sodium sulphite. The reaction rate was fast both in water-in-oil and in bicontinuous ME based on non-ionic surfactants. A comparison was made with this reaction being conducted in a two-phase. system with quats as phase-transfer catalyst but was found to be much less efficient. However, when two other nucleophiles, NaCN and NaNOj, were used the PTC method was almost as efficient as the ME media. It seems that in the case of decyl sulphonate there is a strong ion pair formation between the product and the PTC. The rate in the ME media could be further increased by addition of a small amount of a cationic surfactant. 

The sulphite aftertreatment is particularly important with permonosulphuric acid treatment. Evidence for the underlying mechanism is available from analysis of sulphur oxidation products formed in the various processes (Table 10.34). It is evident from these results that the concentration of RSS()5 anionic groups necessary to change the hydration of the fibre surface is achieved by the reaction of bisulphite with cystine monoxide residues to give the required cysteine-S-sulphonate groups [311]. 

The crude product contains isomers other than that required and also nitrated phenolic compounds resulting from side reactions. The usual method of purification is to treat the crude product with sodium sulphite, which converts asymmetric trinitro compounds to sulphonic acid derivatives, and to wash out the resulting soluble products with alkaline water. The purity of the product is determined by the melting point, the minimum value for Grade I TNT commonly being 80-2°C. Unless adequate purity is achieved, slow exudation of impurities can occur during storage and the TNT then becomes insensitive. 

A suitable example is Cl Acid Blue 27 (6.37 X = NHCH3), which is made from 4-bromo-l-methylaminoanthraquinone by nucleophilic displacement followed by sulphonation. Some commercial acid dyes based on 1,4-diaminoanthraquinone contain substituents in both the 2- and the 3-positions. Thus, for example, Cl Acid Violet 41 (6.38) is produced by the condensation of l,4-diamino-2,3-dichloroanthraquinone with phenol in the presence of sodium sulphite and manganese dioxide. 

In the sulphite pulping process wood cut into pieces is subjected to kiering in a calcium bisulphite solution under a pressure of 3-8 kg/cm2, at 120-145°C for 7-30 hr. The higher the temperature, the shorter the time of boiling. Substances accompanying cellulose dissolve in the liquor. Lignin is converted into a soluble lignin sulphonic acid. Cellulose is isolated from the solution, known as sulphite cellulose lye, and washed with water. 

F. Raschig mixed a mol of potassium nitrite dissolved in as little water as possible with a well-cooled soln. of 2 mols of potassium hydrosulphite, and added a cold sat. soln. of about 2 mols of potassium chloride. In 24 hrs., the needle-like crystals of nitrilosulphonate were separated from the crystalline crust of the nitrilo-disulphonate by washing. The latter salt can be purified by crystallization from warm water rendered alkaline by ammonia or potassium hydroxide. A. Claus also made the salt by mixing 4 mols of potassium sulphite and one of potassium nitrite. The soln. is filtered from the crystals of nitrilosulphonate, and in about 10-12 hrs. it deposits crystals of dipotassium nitrilodisulphonate. He also made the same salt by crystallization from a soln. of potassium nitrosyl sulphonate in warm water. 

Isomeric Sulphites.—The evidence is this —Sulphur alcohol or ethyl-hydrosulphide (also termed mercaptan ), when oxidised by boiling with dilute nitric acid, is converted into ethyl-sulphonic acid, thus ... 

Chemistry and general properties. The main challenge in the manufacture of paraffin sulphonates is the lack of a reactive function in the paraffin (alkane) hydrophobe but this is overcome by using the Strecker reaction or a variant of it. The classical Strecker reaction (shown in Figure 4.10) uses a chloroalkane (which can be made by the reaction of a chlorinating agent with an alcohol) and sodium sulphite. 

One of the typical reactions of aromatic nitro compounds with two or more nitro groups is that with sodium sulphite. Here one of the nitro groups is replaced by a sulphonic group (as its sodium salt) and sodium nitrate is formed ... 

As Muraour [103] found, the reaction of sodium sulphite was not confined to unsymmetrical trinitro derivatives of toluene, a- Trinitrotoluene also reacted with Na2S03 to form dinitrotoluene sulphonic acid, the difference lying in the fact that the reaction proceeds much more slowly than with unsymmetrical isomers. A 3% solution of Na2S03, acting for 1 hr, dissolves at room temperature about 1% of a- trinitrotoluene. 

Muraour observed the important fact that trinitro-m-xylene reacts with sodium sulphite only with great difficulty, while trinitromesitylene does not react with it at all. Tetranitromethane, which is a common impurity of TNT, reacts with sodium sulphite to yield a water-soluble salt of sulphonic acid (p. 339). 

Schwicker s procedure for making the compounds was to neutralize potassium hydrogen sulphite with sodium carbonate, and sodium hydrogen sulphite with potassium carbonate. The first isomeride is represented as potassium sodio-sulphonate, and crystallizes with two molecules of water the second is assumed to be sodium potassio-sidphonaie, and crystallizes with one molecule of water. 

Reaction of nitrosyl disulphonate, 0N(S03), with hydroxylamine-N-sulphonate is reported to be subject to catalysis by ferric salts at low concentrations, and to depend on the alkalinity through the hydrolysis of the catalyst . In mildly alkaline solution (pH 6-11), the rates of decomposition of this sul-phonate have been shown to be consistent with the existence of two reaction paths, one forming NO and the other sulphite radicals . The processes are assumed to represent bimolecular nucleophilic substitution by water. 

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