Disclosed are merocyanine derivatives of formula R1 and R2 Independently from each other are branched C4-C22alkyl or branched C4-C12 alkenyl R3 and R4 independently from each other are cyano COR7, COOR7 CONR7R8: SO2(C8- C12)aryl C2-C12alk-l-enyl C3-C12cycloaik-1-enyl C2-C12alk-1-inyl C2-C12heteroalkyl C3- C5heterocycloalkyl C8-C10aryi or C1-C9heteroaryl wherein at least one of R3 and R4is cyano R5 and R8 independently from each other are hydrogen C1-C8aikyl C5-C8cydoalkyl which may be substituted by one or more than one C1-C4alkifl and R7 and Ra independently from each other are hydrogen: C1-C22alkyl C2-C12alkenyl C2- C12alkinyl C1-C12cydoalkyl C1-C12cycloalkenyl -(CH2),COOH C7-C12aralkyl C1- C12heteroalkyl C2-C11heteroaralkyl C6-C10aryl C1-C9heteroaryl. The compounds are useful as UV absorbers for protecting human hair and skin against the damaging effect of UV radiation.
