Improvements in or relating to the alkylation of phenols and naphthols

摘要

Phenols having at least one unsubstituted ortho or para position such as phenol, cresols and xylenols, and naphthols having at least one corresponding position unsubstituted, i.e. a -naphthol having the 2- and/or 4-position unsubstituted or a b -naphthol having a 2-, 3- and/or 6-position unsubstituted, are alkylated by reaction with an olefine in the presence of a cation exchange resin of the sulphonated polymer type as a catalyst. Specified olefines include aliphatic olefines of the type R.(CH3).C=CHR1 where R and R1 may be hydrogen atoms or alkyl groups of 1-5 carbon atoms, e.g. propylene, iso-butene, amylenes and octenes, cycloaliphatic olefines such as cyclohexenes and cyclopentenes which may be substituted by alkyl groups and aromatic olefines such as styrene or a -methylstyrene. Particularly suitable cation exchange resins are those of the sulphonated polystyrene and phenol/sodium bisulphite/formaldehyde type. In examples: "Zeokarb" (Registered Trade Mark) and "Amberlite" (Registered Trade Mark) cation-exchange resins comprising nuclear sulphonated phenolic, sulphonated polystyrene or phenol/sodium bisulphite/formaldehyde resins are used as catalysts in the reaction between (1) p-cresol and iso-butene to give 4-methyl-6-tert-butylphenol; (2) p-cresol and cyclohexene to give 4-methyl-2-cyclohexyl phenol; (3) phenol and diisobutene to give octylphenol; (4) p-cresol and 1-methylcyclohexene to give 2 - a - methylcyclohexyl - 4 - methylphenol; (5) a mixture of 2 : 4- and 2 : 5-dimethylphenol and isobutene to give 6-tert-butyl-2 : 4-dimethylphenol and tert-butyl-2 : 5-dimethylphenol; (6) p-cresol and 1-methylcyclohexene to give 2-a -methylcyclohexyl-4-methylphenol. Diisobutene is prepared by treating tertiary butanol with sulphuric acid.