BENZOFURAN DERIVATIVES, PROCESS FOR THEIR PREPARATION AND THEIR USE AS OPTICAL BRIGHTENERS

摘要

Novel benzofuran containing a benzimidazolyl group are obtained by reacting a benzofuran containing a carboxylic acid halide group with either an ortho-phenylene diamine or an ortho-nitro-aniline derivative, in the latter case reducing the nitro intermediate to the corresponding (aminophenyl)-amide and splitting off water by closing the imidazole ring. The products are optical brighteners, especially for acrylonitrile polymers.