Process for preparing bisindenylalkanes

Abstract

The present invention relates to a process for preparing bisindenylalkanes of formula I: 1 wherein R1, R2, R3, and R4 independently represent H or a C1-C6 hydrocarbon group or R1 and R2 or R1 and R3 or R3 and R4 together with the carbon atoms to which they are attached form a saturated or unsaturated 5- or 6-membered ring, said ring being optionally substituted with a C1-C4 hydrocarbon group, and R5 represents a C1-C6 hydrocarbon group, comprising reacting, at a temperature which does not exceed about 5° C., a metallated indene of formula II with a disubstituted hydrocarbon of formula III: 2 wherein R1, R2, R3, R4, and R5 have the same meaning as defined above, M represents a metal ion, and X independently represents a suitable leaving group, in a suitable reaction medium wherein the molar ratio of II to III is 2.05 or higher. The process is particularly suitable for preparing bisindenylethane, i.e., R1-R4 represent H and R5 represents an ethylene group.

Dependencies are inferred from the claim text.