Methyl phenol sulphone

Sodium petroleum sulphonates or calcium dinonylnaphthalene sulphonate can be applied as rust preventing additives and the catalytic effect of copper can be retarded by 2-mercaptobenzothiazole. Depending on operating temperature, various oxidation inhibitors may be used. Thus, 2,6-di-fert-butyl-4-methyl phenol is an effective inhibitor below 120 C while phenyl-alpha-naphthylamine is widely used in greases at low temperatures and above 120" C and phenothiazine is effective especially at temperatures above 150" C. Special compounds used as oxidation inhibitors for greases in the food industry are dilauryl thiodipropionate or citric acid. 

Usually prepared from the corresponding sulphonic acids by alkali fusion, methylation of phenol or from the aminotoluene by treatment with nitrous acid followed by boiling. Both o- and p-cresol are used as end components in azo dyes. 

Poly(ethylene terephtlhalate) Phenol-formaldehyde Polyimide Polyisobutylene Poly(methyl methacrylate), acrylic Poly-4-methylpentene-1 Polyoxymethylene polyformaldehyde, acetal Polypropylene Polyphenylene ether Polyphenylene oxide Poly(phenylene sulphide) Poly(phenylene sulphone) Polystyrene Polysulfone Polytetrafluoroethylene Polyurethane Poly(vinyl acetate) Poly(vinyl alcohol) Poly(vinyl butyral) Poly(vinyl chloride) Poly(vinylidene chloride) Poly(vinylidene fluoride) Poly(vinyl formal) Polyvinylcarbazole Styrene Acrylonitrile Styrene butadiene rubber Styrene-butadiene-styrene Urea-formaldehyde Unsaturated polyester... 

Solid esters are easily crystallisable materials. It is important to note that esters of alcohols must be recrystallised either from non-hydroxylic solvents (e.g. toluene) or from the alcohol from which the ester is derived. Thus methyl esters should be crystallised from methanol or methanol/toluene, but not from ethanol, n-butanol or other alcohols, in order to avoid alcohol exchange and contamination of the ester with a second ester. Useful solvents for crystallisation are the corresponding alcohols or aqueous alcohols, toluene, toluene/petroleum ether, and chloroform (ethanol-free)/toluene. Carboxylic acid esters derived from phenols are more difficult to hydrolyse and exchange, hence any alcoholic solvent can be used freely. Sulphonic acid esters of phenols are even more resistant to hydrolysis they can safely be crystallised not only from the above solvents but also from acetic acid, aqueous acetic acid or boiling n-butanol. 

Treatment of (31) with crotyl chloride-potassium carbonate in DMF afforded (33), which was converted into (34) by heating in a sealed tube. Methylation of the phenol (34) with methyl iodide-potassium carbonate gave (35). Osmic acid-sodium periodate oxidation produced the keto-aldehyde (36). Acetalization by standard methods gave the diacetal (37). Reduction of (37) with lithium in liquid ammonia and subsequent toluene-p-sulphonic acid work-up afforded (38) in a yield of 50 %. A vinylogous aldol condensation was effected with methan-olic potassium hydroxide. The resulting mixture was oxidized with chromium... 

Birch reduction of 12-methoxypodocarpa-8,l l,13-trien-19-ol has been investigated and methods have been developed for converting the C-12 ketones into C-13 ketones. An alternative approachhas been used to transpose the aromatic oxygen function from C-12 to C-13. The best route involved mononitration of methyl podocarpate (57), reduction of the nitrophenol toluene-p-sulphonate (58) to an amine (59) with stannous chloride and then Raney nickel, and finally diazotization with isopentenyl nitrite in cold acidic methanol to atTord the phenol ether. 

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