4-Chlorobenzenesulfonyl chloride

Chlorobenzenesulfonyl chloride [98-60-2] M 211.1, m 53 , b 141 /15mm. Crystd from ether in powdered Dry-ice, after soln had been washed with 10% NaOH until colourless and dried with Na2S04. 

Nitro Dyes. 2-Nitrodiphenylamines are readily obtained by condensation of derivatives of 2-nitrochlorobenzene 88-73-3] with suitable aromatic amines. Because of their accessibility and good lightfastness, these dyes became very important for dyeing cellulose acetate and, more recently, have gained a solid position as disperse dyes for polyester fibers. This is especially true for the reaction product of 1 mol of 3-nitro-4-chlorobenzenesulfonyl chloride [97-08-5] and 2 mol of aniline. An exhaustive review of the constitution and color of nitro dyes is given by Merian [40], The yellow nitroacridones may also be classified in this group. 

Zinc dust (120 g.) is added (30 minutes) with stirring to a mixture of 72 g. (0.34 mole) of p-chlorobenzenesulfonyl chloride (p. 72),... 

The reaction mixture was allowed to warm gradually to 50°C. The reaction was quenched by pouring into ice water. The aqueous suspension was heated to hydrolyze p-chlorobenzenesulfonyl chloride (II) to the water-soluble sulfonic acid. The desired product was filtered and washed with water until essentially neutral. Bis (4-chlorophenyl) sulfone was purified by recrystallization from benzene—m.p. 145°-147°C (4). Extremely low yields were obtained by this process. By contrast, yields in excess of 90% have been reported in processes that involve the reaction of chlorobenzene with sulfur trioxide and dimethyl or diethyl sulfate (5, 6). 

Chlorobenzenedisulfonic acid This is best prepared by heating /7-chlorobenzenesulfonyl chloride and sulfuric acid monohydrate (4 parts) slowly to 160-180°, and then until evolution of hydrogen chloride ceases. The mixture is poured into water and worked up by chalking as described above. 

Chlorobenzenesulfonyl chloride 216 Chlorobenzene (20 g) is added from a dropping funnel, during 2 h, to chlorosulfuric acid (60 g), which is cooled to —15°. The mixture is set aside with occasional shaking for 2 h at —5° to —10° and then for 12 h at room temperature, after which it is poured on ice. The oil is separated and distilled in a vacuum. The sulfonyl chloride (22 g m.p. 53°) passes over at 144°/15 mm recrystallization of the residue from glacial acetic acid gives pure bis-(/ -chlorophenyl) sulfone (5 g). 

The sulfonate (1) is prepared by the reaction of 6-chloro-N-hydroxybenzo-triazole with p-chlorobenzenesulfonyl chloride under Schotten-Baumann conditions. ... 

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