CATALYTIC DEHYDROGENATION OF IMINODIBENZYL TO IMINOSTILBENE - A COMPARISON OF POTASSIUM-PROMOTED MANGANESE, IRON AND COBALT OXIDE CATALYSTS

The dehydrogenation of iminodibenzyl (10,11-dihydro-5-dibenz[b.f]azepi ne) to iminostilbene (5H-dibenz[b.f]azepine) was investigated over pot assium-promoted oxides of manganese, iron and cobalt. Both unsupported oxides as well as corresponding oxides supported on magnesium oxide w ere examined. Catalytic tests were carried out in a continuous fixed-b ed reactor in the presence of steam in the temperature range of 400-55 0 degrees C and at atmospheric pressure. Unsupported, potassium-promot ed iron oxide proved to be the most suitable catalyst for the dehydrog enation of iminodibenzyl, yielding iminostilbene with 80% selectivity at nearly 100% conversion.