Process for the preparation of sterically hindered hydroxphenylcarboxylic acid esters
AssigneeCiba-Geigy Corporation
InventorsIvan Orban, Eduard Troxler
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Abstract
If the transesterification of esters of the formula ##STR1## with alcohols of the formula III A--(OH).sub.m is catalyzed by successive treatment with catalytic amounts (a) of a tin compound of a metal of the fourth main group or the fourth sub-group of the periodic system and (b) of an acid earth, compounds of the formula I ##STR2## are obtained in virtually quantitative yield. The products thus obtained contain no troublesome by-products and do not have to be additionally purified. R is methyl or ethyl, A is a radical derived from an m-hydric aliphatic alcohol, n is 0 to 2, and m is 1 to 4.
Claims8
A process for the preparation of a compound of formula I ##STR11## in which n is a number from 0 to 2, m is a number from 1 to 4 and A is a radical which has 2 to 18 carbon atoms and is derived from an m-hydric aliphatic alcohol, by transesterifying about m mols of an ester of formula (II) ##STR12## in which R is methyl or ethyl, with an alcohol of formula III
- A--OH).sub.m (III)
- which comprises catalysing the transesterification by successive treatment under atmospheric pressure in the presence of an inert solvent with a catalytic amount of (a) a tin compound of formula V ##STR13## in which R.sub.2 is C.sub.4 -C.sub.18 -alkyl, and (b) an acid earth.
Dependencies are inferred from the claim text.