Process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine

摘要

The invention provides a process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine, which comprises the two following steps (a) and (b): (a) treatment of a toluidine isomer mixture or of the not intended toluidine isomer or of one of the not intended toluidine isomers with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type, (b) isolation of the intended isomer or one of the intended isomers from the isomer mixture formed in step (a) by selective adsorption to a medium-pore or large-pore zeolite and subsequent desorption, furthermore discharge of the isolated isomer and recycling of the remaining isomer mixture to step (a).