Process for the production of an indene compound and its use for the production of a metallocene catalyst

A very effective catalyst system for olefin polymerization comprising a cocatalyst, preferably an aluminoxane and a metallocene of formula I wherein preferably M {SUP, 1} is Zr or Hf, R {SUP, 1} YR {SUP, 2} are alkyl or halogen, R {sup 3} is hydrogen, R {SUP, 4} AR {SUP, 6} are alkyl or aryl, - (CR {SUP, 8} R {SUP, 9}) {SUB , M} R {SUP, 7} - (CR {SUP, 8} R {SUP, 9}) {SUB, N} is a string of one or more members, wherein R {SUP, 7} CAN BE A hetero-atom (n.), YM + N is zero or 1.