GB1020460A - Alkylation of hydroxy aromatic compounds - Google Patents

Abstract

In the alkylation of aromatic hydroxy compounds by reaction with an olefine in the presence of an acid-reacting refractory inorganic oxide catalyst, a small proportion of water (0.08-5%) is included in the reaction mixture, whereby the proportion of p-alkylated product relative to the total alkylated product is increased. Specified aromatic hydroxy compounds which may be treated are phenol, resorcinol, catechol, o- and m-cresol, o- and m-ethylphenol, o- and m-propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and undecylphenols, o- and m-methoxy, ethoxy, propoxy and butyloxyphenols, 2,6- and 2,3-dimethoxy- or diethoxyphenols, o- and m-cyclopentoxy, cyclohexoxy and cycloheptoxyphenols and o- and m-halo-and nitro-phenols. Reference is made also to the alkylation of polynuclear aromatic hydroxy compounds. Specified olefines are ethylene, propylene, 1- and 2-butenes, isobutylene, pentenes, hexenes and heptenes and mixtures thereof, propylene trimer, tetramer and pentamer, butadiene and isoprene. Reference is made also to the use of non-conjugated diolefines, olefines obtained in the thermal and catalytic cracking of oil, products from the dehydrogenation of paraffinic hydrocarbons, and products from the dehydration of alcohols. Specified catalysts are alumina treated with hydrogen fluoride, hydrogen chloride or boron fluoride, silica-alumina, silica-magnesia, titanium dioxide, zirconium dioxide, chromia, zinc oxide, silica-alumina-magnesia, silica-aluminazirconia, chromia-alumina, alumina-boria and silica-zirconia. The oxides may be treated with an acid. The alkylation may be effected at 25-250 DEG C. under a pressure ranging from atmospheric up to 100 atm., and the process may be a batch process or a continuous process, several methods of procedure being indicated. Examples are given in which (1) phenol and nonene are reacted at 185 DEG C. and 17.7 atm. pressure in the presence of a silica-alumina catalyst and 0.1% by weight of water to give an alkylation product containing 87% by weight of p-nonylphenol; if the proportion of water is raised to 0.5%, a product containing 97% of p-nonylphenol is obtained; (2) o-cresol and isobutylene are reacted at 250 DEG C. and 34 atm. pressure in the presence of an aluminaboron fluoride catalyst and 0.2% by weight of water; a product rich in the p-butylcresol isomer is obtained; (3) o-cresol and propylene trimer are reacted at 150 DEG C. and 20.4 atm. pressure in the presence of an alumina-boria catalyst and 0.75% by weight of water to yield p-nonylcresol.