Hybrid process for preparing a tri-substituted triazine

Abstract

The prior art solvent process for the manufacture of an oxo-piperazinyl triazine (PIP-T) compound required carrying out the reaction between an appropriately hindered cyclic amine and cyanuric chloride in the presence of caustic catalyst, in alkylbenzene solution, typically toluene. The chloride ions generated during the reaction, in presence of water present in the reaction zone, produced serious corrosion and resulted in off-color product which had a melt absorptivity greater than 3.5 mL/gm.cm. This 'color' in the product made the product generally unmarketable. Another process to make a PIP-T termed 'the solventless' process used no toluene solvent, and no caustic but required such a very large excess of amine that the catalytic function of the amine.HCl salt went unnoticed. In the novel process, referred to as the 'hybrid' process, this catalytic function allows the use of only as much toluene in the reactor as is needed to keep the product formed and the excess amine in solution, and the use of less than a two-fold molar excess over the molar amount to displace each chlorine atom of the cyanuric chloride. The result is exceptionally high purity and yield with color no greater than that which the marketplace accepts.