| abstract |
Novel benzofuranyl benzimidazoles of the formula ##STR1## wherein R 1 represents a hydrogen atom, an alkenyloxy or cycloalkloxy radical, an unsubstituted or substituted alkoxy, phenylalkoxy or phenoxy radical, each of n R 2 and R 3 independently represents a hydrogen atom, an alkyl or alkoxy radical, a halogen atom, or, if R 1 represents hydrogen, together in the ortho-position to each other they represent a radical of the formula --CH═CH--CH═CH--, --O--CH 2 --O-- or --O--CH 2 --CH 2 --O--, n R 4 represents a hydrogen atom, an alkyl, alkoxy or phenyl radical, n R 5 represents a sulpho or carboxyl group or the functional derivatives thereof including the cyano group or the trifluoromethyl group, n R 6 represents a hydrogen or halogen atom, an alkyl or alkoxy radical, n R 7 represents a cycloalkyl, alkenyl, or unsubstituted or substituted alkyl, phenyl or phenylalkyl radical, or, if n is O, also represents a hydrogen atom, n R 8 represents a hydrogen atom, a cycloalkyl, alkenyl, or unsubstituted or substituted alkyl or phenylalkyl radical, n A w ⊖ represents a colorless anion of an inorganic or organic acid and n w represents the valency of the anion A, and n n is 0 or 1, n their preparation as well as their use as optical brighteners are disclosed. |