The invention relates to ultraviolet light absorbing compounds, their preparation and uses as protective agents and stabilizers in coatings, plastics and topically applied products. The compounds are ketone derivatives of 2-(2-hydroxyphenol)benzotriazole of formula I, where R1 is hydrogen atom, or a halogen atom, or a straight-chain or branched lower alkyl or lower alkoxy of 1 to 4 carbon atoms; R2 is an unsubtituted or substituted aryl group or an unsubstituted or substituted straight-chain or branched alkyl having 1 to 18 carbon atoms or a cycloaliphatic group having 5 to 6 carbon atoms; and R3 is a straight-chain or branched alkyl or alkylaryl group or alkoxyl or phenyl or phenyl substituted with alkyl, cycloalkyl, carboalkoxy, chlorine or arylalkyl groups.