Production of substituted phenols

摘要

Phenols are substituted in the nucleus by passing a mixture comprising a phenol having at least one free ortho or para position and an alkylating, cycloalkylating or alkenylating agent through a thermally lagged bed of a particulate catalyst for the substitution reaction, and correlating (a) the initial composition and temperature of the reaction mixture fed to the bed, (b) the heat transfer to and from the thermally lagged bed of catalyst and (c) the rate at which the reacted mixture is withdrawn from the bed of catalyst so as to provide a predetermined rising temperature gradient from entry to exit from the bed and a predetermined temperature at the exit. The temperatures of the reaction mixture entering the reactor and the temperature of crude mixture withdrawn from the reactor are preferably at least 40 DEG C. and at least 80 DEG C., respectively. The rate of flow of mixture is selected to produce a degree of reaction completeness of at least 30%, and preferably 80%. The temperature increase along the reactor should be at least 1 DEG C. for each 8% by weight decrease in the percentage of substituting reagent as the reaction mixture passes through the reactor. Catalysts which may be used in the process include sulphonated coal and, preferably, sulphonated cross-linked polymers of a monovinyl aryl compound. Specified phenolic compounds which may be substituted are phenol, the cresols, the ethyl and propyl phenols, the xylenols, carvacrol, thymol, pyrocatechol, resorcinol, pyrogallol, phloroglucinol, guaicacol, orcinol and hydroquinone. Substituting reagents which may be used are straight chain, secondary and tertiary olefine hydrocarbons, e.g. n-amylene, n-nonene, secondary amylene, tertiary butylene and the polymers of propylene and butylene; cycloaliphatic olefines, e.g. cyclohexene; aromatic hydrocarbon olefines, e.g. styrene; olefinic aliphatic acids, e.g. oleic acid; diolefines, e.g. butadiene; and halogenated olefines. Compounds which are readily transformed into olefines, e.g. secondary and tertiary alcohols, alkyl halides and ethers, may also be used. The process is advantageously carried out under substantially anhydrous conditions. In examples phenol is reacted with propylene polymers. Specification 981,828 is referred to.