Patent GB-589051-A (GB)
Title: Improvements relating to the preparation of alkylhydroxyphenyl dialkylaminophenyl sulphides
IPC: C11B5/00
Filed: 1944-08-17
Abstract: Alkylhydroxyphenyl-dialkylaminophenyl sulphides, of the general formula <FORM:0589051/IV/1> in which R1 and R2 represent hydrogen or alkyl groups of from 1 to 20 carbon atoms, at least one being an alkyl group and the two together preferably containing not more than 20 (e.g. 8 to 14) carbon atoms, R3 and R4 represent alkyl groups of from 1 to 5 carbon atoms each, and n is 1 or 2, are manufactured by reacting an alkylphenol containing groups R1 and R2 and an N-dialkylaniline C6H5-NR3R4 with sulphur chloride (in which case n=2) or sulphur dichloride (n=1).  The reaction may be carried out in a solvent, e.g. carbon disulphide or, preferably, a chlorinated solvent such as ethylene dichloride, trichlorethylene, carbon tetrachloride or chloroform, at or preferably below room temperature, but if necessary with heating, e.g. to 40-50 DEG  C., to complete the reaction, i.e. until hydrogen chloride is no longer evolved.  The products may be recovered by adding a dilute solution of mild alkali, removing the aqueous layer and evaporating the solvent, if necessary under reduced pressure in the last stages.  They may be converted into metal salts by adding a metal hydroxide, e.g. barium, calcium, sodium or potassium hydroxide, and heating to remove the water of reaction, by reaction with a metal, e.g. powdered aluminium, magnesium turnings or metallic calcium, by heating with an alcoholate of a low boiling alcohol such as methanol; other metal salts are obtainable by double decomposition, e.g. by heating the sodium salt with a compound such as zinc chloride, aluminium sulphate or copper nitrate.  The products are useful as corrosion inhibitors, e.g. in hydrocarbon oils, as inhibitors in metal pickling baths, as antioxidants, e.g. for rubber, vegetable oils and gasoline, or, especially in the form of metal salts, as detergents.  In examples: (1) diethylaniline and 2 : 4-di-tert.-amylphenol are treated with sulphur monochloride in ethylene dichloride to produce 2-hydroxy-3 : 5-di-tert.-amyl-41-diethylaminodiphenyl disulphide, which is converted into its barium salt by heating with barium hydroxide octahydrate and n-butyl alcohol; (2) the diethylaniline in (1) is replaced by dimethylaniline; (3) dimethylaniline and p-tert.-octylphenol are treated as in (1); (4) diethylaniline and 2 : 4 - di - tert. - octylphenol (obtainable by condensing phenol with two molecular proportions of di-isobutylene in the presence of aluminium chloride) are similarly treated; (5) the di-tert.-octylphenol in (4) is replaced by p-dodecylphenol; (6) dimethylaniline and 2 : 4-di-tert.-amylphenol are treated with sulphur dichloride in ethylene dichloride, yielding 2 - hydroxy - 3 : 5 - di - tert. - amyl - 41-dimethylaminodiphenyl sulphide; (7) dimethylaniline and p-tert.-butyl-o-cresol are treated as in (1), and the reaction mixture, after washing with sodium carbonate solution and addition of n-butyl alcohol, is mixed with S.A.E. #10 oil and the solvents are distilled off under reduced pressure.  Additional starting materials specified are: p-cresol, 2 : 4-dimethylphenol and p-octadecylphenol; methylethylaniline, dipropylaniline, methylbutylaniline and diamylaniline.ALSO:As inhibitors in metal pickling baths may be employed alkylhydroxyphenyl - dialkylamino - phenyl sulphides of the general formula <FORM:0589051/II/1> (wherein R1 and R2 represent hydrogen or alkyl groups of from 1 to 20 carbon atoms, at least one being an alkyl group and the two together preferably containing not more than 20, e.g., 8 to 14, carbon atoms, R3 and R4 represent alkyl groups of 1 to 5 carbon atoms each, and n is 1 or 2), or metal salts thereof.ALSO:As antioxidants for rubber may be employed alkylhydroxyphenyl - dialkylaminophenyl sulphides of the general formula <FORM:0589051/V/1> (where R1 and R2 represent hydrogen or alkyl groups of from 1 to 20 carbon atoms, at least one being an alkyl group and the two together preferably containing not more that 20, e.g., 8 to 14, carbon atoms, R3 and R4 represent alkyl groups of 1 to 5 carbon atoms each, and n is 1 or 2), or metal salts thereof.