Patent ID: 7253292

Claim:
A process for preparing a cyclopentadiene derivative having formula (I) wherein T 1 is selected from the group consisting of oxygen (O), sulphur (S) and NR, wherein R is selected from the group consisting of linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -atkylaryl, and C 7 -C 20 -arylalky radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 1 , R 2 , equal to or different from each other are hydrogen or a linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl or C 7 -C 20 -arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or they can form a C 4 -C 7 ring optionally containing O, S, N, P or Si atoms that can bear substituents; W is a moiety of formula (a) or (b) wherein T 2 , T 3 , T 4 , T 5 equal to or different from each other are selected from the group consisting of nitrogen (N) and CR 3 wherein R 3 is hydrogen or a linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -atkylaryl or C 7 -C 20 -arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or two adjacent R 3 groups can form a C 4 -C 7 ring optionally containing O, S, N, P or Si atoms, wherein said ring can bear substituents; T 6 has the same meaning as T 1 ; T 7 and T 8 equal to or different from each other are selected from N and CR 3 wherein R 3 is hydrogen or a linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl or C 7 -C 20 -arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; optionally two adjacent R 3 groups can form a C 4 -C 7 ring optionally containing O, S, N, P or Si atoms, said ring can bear substituents; with the proviso that when T 6 is different from NR, T 7 and T 8 are both CR 3; said process comprising the following steps: a) reacting a compound of formula (II) with a compound of formula (III) in the presence of a coupling system, wherein X is selected from the group consisting of chlorine, iodine, and bromine; thereby forming a compound of formula (IV) b) contacting the compound of formula (IV) with a carbonylating system; thereby forming a compound of formula (IVa) and; c) treating the compound of formula (IVa) with a reducing agent.