42880-08-0Relevant articles and documents
Process for preparing chromophore-substituted vinyl-halomethyl-s-triazines
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, (2008/06/13)
An improved method for the preparation of chromophore-substituted vinyl-halomethyl-s-triazines especially 2-(p-methoxystyryl)-4,6-bis-(trichloromethyl)-s-triazine. In the known preparation of these compounds, a two step procedure is utilized wherein an intermediate reaction product has to be isolated. This step of separating the intermediate is eliminated in the present process by dissolving the crude reaction product obtained in the first step in toluene, removing excess hydrogen chloride gas and catalysts by purging the reaction product solution with an inert gas, and then reacting p-anisaldehyde with the toluene solution of the reaction product mixture using piperidinium acetate catalyst to obtain 2-(p-methoxystyryl)-4,6-bis-(trichloromethyl)-s-triazine. As a further improvement of the art the Knoevenagel-type condensation is run until no further water is evolved. At this point the product formed is isolated by filtration and a like amount of catalyst as a second charge is added. Again, the reaction is carried out until no further water is evolved and further product is isolated by filtration.