BIOCIDAL BENZYLBIPHENYL DERIVATIVES

This invention concerns compounds of formula.stereochemically isomeric forms thereof, acid or base addition salts thereof, N-oxides thereof, or quaternary ammonium derivatives thereof, wherein the dotted line is an optional bond; X is a direct bond when the dotted line represents a bond, or X is hydrogen or hydroxy, when the dotted line does not represent a bond; R1, R2, R5 and R6 are each independently selected from hydrogen, halo, hydroxy, C1-4alkyl, C1-4alkyloxy, -SO3H, and the like; R3 and R4 are each independently selected from hydrogen, halo, hydroxy, C1-4alkyl, C1-4alkyloxy, nitro, amino, cyano, trifluoromethyl, or trifluoromethoxy; L is a radical of formulawherein A1 is a direct bond or C1-6alkanediyl; A2 is C2-6alkanediyl; and R7 to R11 are hydrogen, C1-6alkyl, aminoC1-6alkyl and the like; having biocidal properties; their preparation, compositions containing them and their use as a biocide.