Abstract: A method for preparing sterically hindered bis- or polyphenols of the formula: ##STR1## wherein R' is hydrogen, a C.sub.1 -C.sub.4 alkyl; R" and R"' the same or different and are each: ##STR2## wherein R is a tertiary C.sub.4 -C.sub.8 alkyl, R.sub.1 and R.sub.2 are the same or different and represent a C.sub.1 -C.sub.8 alkyl or a C.sub.6 -C.sub.8 cycloalkyl, or a C.sub.7 -C.sub.9 aralkyl, which comprises reacting the starting sterically hindered 2,4,6-trialkylphenols of the formula: ##STR3## wherein A is a C.sub.1 -C.sub.8 alkyl or a C.sub.6 -C.sub.8 cycloalkyl or a C.sub.7 -C.sub.9 aralkyl or a 3,5-dialkyl-2-hydroxybenzyl of the formula: ##STR4## B is a C.sub.1 -C.sub.8 alkyl, or a C.sub.6 -C.sub.8 cycloalkyl, or a C.sub.7 -C.sub.9 aralkyl, or a 3,5-dialkyl-4-hydroxybenzyl of the formula: ##STR5## wherein R.sub.1 and R are as identified above, with acetals, aldehydes or donors of C.sub.1 -C.sub.5 aldehydes in an acidic medium at a temperature within the range of from 60.degree. to 200.degree. C.

Abstract: A method for the production of 2,4,6-tri(3,5-ditertiary butyl-4-hydroxybenzyl)mesitylene which resides in treating a mesitylene solution in chloroalkane simultaneously with sulfuric acid used as a catalyst and a solution of 2,6-ditertiary butyl-4-methoxymethylphenol or bis-3,5-ditertiary butyl-4-hydroxybenzyl ether in chloroalkane at a temperature of -20.degree. to +20.degree. C. This results in a reaction mixture consisting of an acid phase and an organic phase including the target product. The phases are separated. The organic phase is subjected to neutralization by the treatment thereof with gaseous ammonia used as an alkaline agent. The precipitate of ammonium sulfate is separated and chloroalkane is removed from the remaining solution.The proposed method makes it possible to obtain the target product with a yield of 88 to 90% and a melting temperature of 239.degree. to 239.5.degree. C.The method prevents the formation of effluents, and the amount of phenol wastes is considerably reduced.

Abstract: Method of removing aluminum-containing catalyst from phenol alkylation products comprises treating phenol alkylation products with water at a temperature of 165.degree.-250.degree. C., with water being in molar excess to aluminum in a range of 3-20. The resulting residue of meta-aluminate is easily separated by filtration.The present invention allows eliminating constant control of aluminum content in alkylation products, easily removing the catalyst therefrom and eliminating the loss of phenol alkylation products.