Process for the preparation of tert-alkyl esters

A process for the preparation of a tert-alkyl ester of the formula I ##STR13## in which m is 1 or 2, R is C.sub.4 -C.sub.12 tert-alkyl and X, when m=1, is unsubstituted or halogen-substituted alkyl, cycloalkyl, unsubstituted or substituted aryl or aralkyl, or an aromatic heterocyclic radical and, when m=2, is a direct bond, --CH.sub.2).sub.n, in which n can be an integer from 1 to 8, or 1,2-, 1,3- or 1,4-phenylene, by reaction of an ester of the formula II ##STR14## in which m and X are as defined above and R.sub.1 is methyl or ethyl, with m.times.2 to m.times.10 mol of an alcohol of the formula ROH, in which R is as defined above, in the presence of catalytic amounts of a catalyst chosen from the group consisting of dibutyltin oxide, lithium amide, aluminium tert-butylate, potassium tert-butylate, sodium, lithium, potassium, sodium methylate, sodium ethylate and titanium alcoholates, the methanol or ethanol formed being simultaneously distilled off.