The present invention relates to a process for preparing bisindenylalkanes of formula I:
1
wherein R
1
, R
2
, R
3
, and R
4
independently represent H or a C
1
-C
6
hydrocarbon group or R
1
and R
2
or R
1
and R
3
or R
3
and R
4
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 C
1
-C
4
hydrocarbon group, and R
5
represents a C
1
-C
6
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 R
1
, R
2
, R
3
, R
4
, and R
5
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., R
1
-R
4
represent H and R
5
represents an ethylene group.
本发明涉及一种制备式I的双烷基联
吡啶的方法:其中R1、R2、R3和R4独立地代表H或C1-C6烃基,或者R1和R2或R1和R3或R3和R4与它们连接的碳原子一起形成饱和或不饱和的5-或6元环,该环可以选修饰有C1-C4烃基,R5代表C1-C6烃基,包括在不超过约5°C的温度下,在适当的反应介质中,使式II的
金属化联
吡啶与式III的二取代烃反应:其中R1、R2、R3、R4和R5的含义如上所定义,M代表
金属离子,X独立地代表适当的离去基,其中II与III的摩尔比为2.05或更高。该方法特别适用于制备双联
吡啶乙烷,即R1-R4代表H,R5代表
乙烯基。