Bayer Aktiengesellschaft

Peter Ziemek

Hans-Josef Buysch

Roderich Raue

Erhard Schellmann

Hans J Hennig

The present invention relates to a process for the preparation of compounds selected from the group consisting of a polyisocyanate containing urea groups and a polyisocyanate containing biuret groups comprising

Process for the preparation of organic polyisocyanates containing urea

Process for the preparation of organic polyisocyanates containing biuret

Polyaminopolyarylmethanes and a monoarylamine are heated in water in the presence of a solid acid catalyst insoluble in the reaction mixture to convert the polyarylaminopolyarylmethanes into diaminodiarylmethanes.

Process for converting polyaminopolyaryl-methanes into

Polyaminopolyarylmethanes and an aromatic monoamine unsubstituted in an ortho or a para position to the amino group are heated in water to produce diaminodiarylmethanes.

Process for the preparation of heterocyclic compounds of the general formula ##SPC1## By condensation of an o-substituted amine of the general formula ##SPC2## With a carbonyl compound of the general formula ##EQU1## in the presence of a hydrazine of the general formula ##EQU2## followed by quaternization if appropriate. In the formulae the radicals have the meaning as indicated below.

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Cologne, Germany

Peter Ziemek