New 4-(tert. butyl)-4'-methoxydibenzoyl methane derivatives, useful for protecting skin or hair, are photostable, photoactivatable sunscreens with high UV absorption capacity

4-(Tert. butyl)-4'-methoxydibenzoyl methane derivatives (I) are new. Dibenzoylmethane derivatives of formula (I) and their salts and solvates are new. [Image] R 1-R 4, R' 1-R' 4H, 1-4C alkyl, 2-4C alkenyl, 2-4C alkynyl, 1-4C alkoxy, halo, OH, NH 2, NO 2, amido or -CO-T; Y : OH, OR or SR; R : 1-4C alkyl; and R 5, R' 5H, 1-4C alkyl, 2-4C alkenyl, 2-4C alkynyl, 5-20C linear or branched, saturated or unsaturated, acylic carbon chain (optionally terminally functionalized and/or interrupted by N (in an amide or amine function) and/or O (in an ether or carboxy function). An independent claim is included for the preparation of (I). N.B. In the disclosure the parent compound 4-(tert. butyl)-4'-methoxydibenzoyl methane, i.e. the keto form of (I; R 1- R 5, R' 1- R' 5= H) or Parsol 1789(RTM), is stated to be known; and the claimed preparation of (I) implies that R 5and/or R' 5must be other than H. La présente invention concerne des composés dérivés de dibenzoylméthane de formule I,ainsi que leurs sels ou solvates, et leur procédé de préparation.Elle concerne également l'utilisation d'un composé de formule (I) en tant qu'agent de protection de la peau ou des cheveux contre les rayonnements UV et un produit cosmétique et/ou dermatologique caractérisé en ce qu'il comprend en tant que principe actif, un composé de formule (I).