| abstract |
Benzofurans, benzothiophenes, indoles, naphthofurans and benzofuranobenzofurans which are substituted by 4-vinyl-phenyl groups wherein the 2-position of the vinyl is substituted by a monovalent aromatic radical having one to three aromatic rings are optical brightening agents useful for whitening and brightening natural and synthetic fibers, papers, resins and the like. The compounds are conveniently prepared by interacting benzofurans, benzothiophenes, indoles, naphthofurans or benzofuranobenzofurans which are substituted by a p-tolyl group, with an aromatic aldehyde or preferably the anil derivative thereof. |