Sulphur dioxide sulphones

The 94% acid from the sulphur dioxide drying towers (above) is used here and its strength brought up to 98 %. This is concentrated sulphuric acid. Stronger acid up to 106% may also be made. This concentration is suitable for sulphonating in, for example, the detergent industry. 

Preparation of the sulphones. Dissolve the 2 4-dinitrophenyl-sulphide in the minimum volume of warm glacial acetic acid and add 3 per cent, potassium permanganate solution with shaking as fast as decolourisation occurs. Use a 50 per cent, excess of potassium permanganate if the sulphide tends to precipitate, add more acetic acid. Just decolourise the solution with sulphur dioxide (or with sodium bisulphite or alcohol) and add 2-3 volumes of crushed ice. Filter off the sulphone, dry, and recrystaUise from alcohol. 

Once the presence of a sulphonate group has been estabhshed (and, if possible, the phenol isolated), the compound may be characterised by the preparation of a derivative. It must be remembered that both sulphoxides RSOR and sulpJiones RSOjR yield sulphur dioxide on fusion with caustic alkali and acidification. 

Sulphur oxides G Sulphur dioxide Sulphur trioxide Coal distillation Combustion of coal and heavy fuel oil Detergents (sulphonation of alkyl benzenes) Electricity generation... 

Low substrate selectivity accompanying high positional selectivity was also found in isopropylation of a range of alkyl and halogenobenzenes by /-propyl bromide or propene in nitromethane, tetramethylene sulphone, sulphur dioxide, or carbon disulphide, as indicated by the relative rates in Table 86. The toluene benzene reactivity ratio was measured under a wide range of conditions, and varied with /-propyl bromide (at 25 °C) from 1.41 (aluminium chloride-sulphur... 

These topics are discussed in more detail in other chapters of this text. Formally, the pyrolytic elimination of sulphur dioxide from a sulphone, with the concomitant formation of a new carbon-carbon bond, constitutes a reduction at sulphur. These reductions have been valuable in the formation of new molecules, especially macrocycles and cyclophanes, and have been reviewed by Vogtle and Rossa205. Pyrolytic elimination of sulphur dioxide has been used by Julia and co workers in the formation of mixtures of isoprenoids206, and by Takayama and collaborators in the stereoselective synthesis of vitamin D, 19-alkanoic acids207. 

The photoextrusion of sulphur dioxide to form cyclophanes or other novel aromatic molecules has been reviewed and studied by Givens208-210, while the photodecomposition of aromatic sulphones to form products of radical coupling reactions has recently also received attention211. 

The lamp method involves combustion of a sample of sulphone in a closed system with an atmosphere of 30% oxygen and 70% carbon dioxide214. The mixture of sulphur dioxide and sulphur trioxide formed is converted in situ to sulphate by oxidation with hydrogen... 

It has already been recorded (p. 142) that hydrogen chloride and sulphur trioxide react to produce chlorosulphonic acid. The alkali chlorides, on the other hand, form chloropyrosulphonates, e.g. C1S02.0. S02.0Na, which are crystalline solids, decomposed by water 2 the alkali fluorides, however, yield the corresponding fluorosulphonates, such as F.S03Na3 (see p. 86). Sodium nitrite produces a nitrosotri-sulphonate, NQ2(S03)3Na.2 Alkali chlorides may be converted to sulphates with evolution of chlorine by the action at 300° to 600° C. of a mixture of sulphur trioxide and air. No fusion occurs nor does the evolved gas contain any sulphur dioxide.4... 

Amidosulphonie Acid, NH2.SOsH, may be obtained by the action of sulphur trioxide on dry ammonia.2 When an aqueous solution of hydroxylamine hydrochloride is saturated with sulphur dioxide and afterwards evaporated, amidosulphonie acid is obtained.3 Potassium imidosulphonate, NH(S03K)2, and potassium nitrilosulphonate, N(SOaK)a, are both decomposed by hot water with formation of potassium amido-sulphonate 4... 

Formation.—When sulphur dioxide is passed into ice-cold fuming nitric acid, crystals of nitrosulphonic. acid separate.1 The acid is also obtained when sulphuric acid is treated with excess of nitrogen peroxide.2 It is also formed by the interaction of sulphur dioxide and nitrogen peroxide both in the absence or presence of water,8 and by the addition in equimolecular proportion of liquid nitrogen tetroxide to chloro-sulphonic acid in the absence of moisture.4 Sulphuric acid acts on either nitrous anhydride or nitrosyl chloride with formation of nitrosulphonic acid, according to the equations ... 

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