GB471010A - Manufacture of aromatic sulphones and of tanning agents - Google Patents

Abstract

Hydroxy sulphones are prepared by heating in a vacuum a sulphonic acid of an aromatic hydrocarbon or of a phenol or phenol ether and an unsulphonated phenol or an unsulphonated derivative thereof containing at least one free hydroxy group, e.g. a hydroxy sulphone. The products, which may be condensed with formaldehyde and an aromatic oxy compound to give tanning agents have wetting properties and may be used for combatting pests. In examples: (1) phenol is sulphonated and heated in vacuo with phenol; water of reaction and also some phenol distils and dioxydiphenylsulphone crystallizes out; both the phenol which distils and the phenol sulphonic acid in solution may be used again; higher yields are obtained if a solvent, e.g. dichlorbenzene or a flux, e.g. a sulphonic acid of toluene, naphthalene or tetrahydronaphthalene, is employed; by adding cresol instead of phenol a mixed sulphone is obtained; (2) 4 : 4<1>-dioxy : 3 : 3<1>-dimethyldiphenylsulphone is obtained by using o-cresol and proceeding as in example (1); (3) m- or p-cresol is sulphonated with oleum and reacted with m- or p-cresol; (4) crude cresol D.A.B.4 is gradually added through a capillary tube to a sulphonated mixture prepared from crude cresol D.A.B.4; by determining the acidity or by observation of the water of reaction the desired proportion of cresolsulphonic acids and dioxyditolylsulphones is obtained; the product is diluted with water, allowed to stand overnight with formaldehyde and rendered weakly acid to congo by the addition of alkali lye; alternatively the product is rendered alkaline to phenolphthalein, the excess cresol removed by distillation and the residue reacted with formaldehyde; liquors directly suitable for tanning are thus prepared; (5) dicresylglycoletherdisulphonic acid is reacted with phenol, cresol or amylphenol; (6) dicresylglycolether is sulphonated and reacted with o-chlorphenol, 2 : 4dichlorphenol or dioxydiphenylsulphone; (7) dioxydiphenylsulphone is reacted with naphthalenesulphonic acid or tetrahydronaphthalenesulphonic acid in vacuo in the presence of sulphuric acid. Specifications 375,160,416,191, and 425,527 are referred to.