Patent ID: 7407648

Claim:
A method of protecting human and animal hair or skin from UV radiation, which comprises contacting said hair or skin with an effective UV-protective amount of a compound of formula wherein R 1 and R 2 are each independently of the other hydrogen; C 1 -C 22 alkyl; cyclo-C 3 -C 8 alkyl; or unsubstituted or C 1 -C 6 alkyl- or C 1 -C 6 alkoxy-substituted C 6 -C 20 aryl; or R 1 and R 2 together with the nitrogen atom linking them form a —(CH 2 ) m — ring which is uninterrupted or interrupted by —O— or by —NH—; R 3 is a cyano group; —COOR 5 ; —CONHR 5 ; —COR 5 ; —SO 2 R 5 ; or —CONR 1 R 5 ; R 4 is a cyano group; —COOR 6 ; —CONHR 6 ; —COR 6 ; —SO 2 R 6 ; or —CONR 2 R 6 ; R 5 and R 6 are each independently of the other C 1 -C 22 alkyl; cyclo-C 3 -C 8 alkyl; or unsubstituted or C 1 -C 6 alkyl-substituted C 6 -C 20 aryl; or R 3 and R 4 together or R 5 and R 6 together form a 5- to 7-membered, monocyclic, carbocyclic or heterocyclic ring; Z 1 and Z 2 are each independently of the other a —(CH 2 ) 1 — group which is uninterrupted or interrupted by —O—, —S—, or by —NR 7 —, and/or is unsubstituted or substituted by C 1 -C 6 alkyl; R 7 is C 1 -C 5 alkyl; l is a number from 1 to 4; m is a number from 1 to 7; n is a number from 1 to 4; when n=2, R 1 , R 5 or R 6 is a bivalent alkyl group; or R 1 and R 2 together with the 2 nitrogen atoms linking them form a —(CH 2 ) m — ring; when n=3, R 1 , R 5 or R 6 is a trivalent alkyl group; when n=4, R 1 , R 5 or R 6 is a tetravalent alkyl group; and R 1 and R 2 in formula (1) are not simultaneously hydrogen.