9,10-Anthraquinone-2-sulfonyl chloride

Alkali sulfites have proved valuable for reduction of sulfonyl chlorides in the anthraquinone series.530... 

Excess Acid. The helpful function of excess sulfuric acid as an inexpensive, low-viscosity solvent for most sulfonic acids is often overlooked because of the difficulty of recovering a product dissolved in it, or because of the disposal problem often encountered. Sulfonation of most of the hydroxyl, amino, nitro, and carboxylic derivatives of benzene, naphthalene, and anthraquinone is facilitated in this manner by the presence of excess acid. The same effect applies to anthraquinone itself, to petroleum lubricant fractions during sulfonation to mahogany and green acids, and to the sulfation of fatty oils. Chlorosulfonic acid, used in large excess for the conversion of aromatic compounds to sulfonyl chlorides by chlorosulfona-tion, functions in a similar manner. 

Sulfonyl chloride, 221-5, Oxid - 9,10-anthraquinone, 286, Maleic anh adduct, 258 9... 

Procedure Into a 10-ml flask (ground-glass joint) provided with a reflux condenser 100 mg of anthraquinone-2-sulfonyl chloride and 0.5 ml of aniline are placed, and the mixture is refluxed on a boiling water bath for 1 hr. After cooling, 10 ml of hydrochloric acid 1 1 are added to the mixture, and the supension formed is thoroughly stirred. The anilide formed is filtered off under suction using a filtration crucible and washed twice with 5 ml of HCl 1 1, twice with 3 ml of water, 2 ml of ethanol, and 2 ml of ether. Yield, 65 mg mp, 197 — 199 C. After crystallization from 0.5 ml of nitrobenzene the product weighed 50 mg, mp 198 — 199 C. 

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