Patent ID: 8450499

Claim:
A process for the preparation of the compound of formula I which process comprises a) reacting the compound of formula II with cyclopentadiene in the presence of an alkylnitrite and an inert solvent to a compound of formula III b) reacting the compound of formula III in the presence of an oxidant and an inert solvent to the compound of formula IV c) hydrogenating the compound of formula IV in the presence of a metal catalyst and an inert solvent under hydrogen atmosphere to the compound of formula V d) reacting the compound of formula V in the presence of a Brönsted acid followed by a reducing agent to the compound of formula VI e) reacting the compound of formula VI with a compound of formula VII in the presence of a base to a compound of formula VIII f) converting the compound of formula VIII in the presence of an oxidising agent to the compound of formula IX and g) reacting the compound of formula IX in the presence of triphenylphosphane/carbon tetrachloride or triphenylphosphane/bromotrichloromethane to the compound of formula I.