Chemistry of hydrocarbon compounds – Compound or reaction product mixture – Aromatic
Reexamination Certificate
2002-02-27
2002-12-03
Shaver, Paul F. (Department: 1621)
Chemistry of hydrocarbon compounds
Compound or reaction product mixture
Aromatic
Reexamination Certificate
active
06489526
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the synthesis of hydrocarbyl-bridged indenes.
DEFINITION
Hydrocarbyl Bridged Indene—means collectively all isomers of a compound of Formula I:
wherein “R” is a hydrocarbyl group.
1,2-bis(indenyl)ethane or EBI—means collectively all isomers of Formula II:
in which the symbol ″(″ indicates a 1,2-bis(indenyl-1)ethane which has a 1,2, 1,2′ double bond (thermodynamic EBI, BRN No. 3055002, CAS RN No. 18657-57-3) or a 2,3 2′,3′ double bond (kinetic EBI, BRN No. 3083835, CAS RN Nos. 15721-07-0, 18686-04-9, 18686-05-0). atoms are asymmetric when substituted.
Each of the ring substituents may be hydrogen or any one to ten carbon atom hydrocarbyl group. Each ring substituent may be the same as or different from any other ring substituent. One to ten carbon atom alkyl groups are preferred. 2,2′ methyl and 4,7, 4′7′ dimethyl EBIs are representative.
BACKGROUND OF THE INVENTION
Meso and rac (racemic) forms of kinetic EBI and thermal isomerization of kinetic to thermodynamic EBI are known phenomena. Maréchal, et al,
Bulletin de la Societe Chimique de France
(1967) 8:2954-2961.
Kinetic and thermodynamic EBI are interchangeably useful separately and in mixtures as ligands for metallocene olefin polymerization catalysts. However, the large-scale production of kinetic EBI is constrained because the thermodynamic isomer is produced at temperatures below about −70° C.; whereas, at higher temperatures low yields of kinetic EBI consequent from Spiro indene and vinylindene impurities may result. See, e.g., Yang, et al.,
SYNLETT
(1996) 147 and Collins, et al.,
J. Organometallic Chem
. (1988) 342:21 (thermodynamic EBI synthesized at −78° C. stirred overnight and warmed to room temperature). See also Ewen, J., et al.,
J.Am.Chem.Soc
. (1987) 109:6544-6545 and Grossman, R., et al.,
Organometallics
(1991) 10:1501-1505 (50% to 80% recrystallized yields of thermodynamic isomer because of the formation of spiroindene by-product).
SUMMARY OF THE INVENTION
This invention provides a method for the synthesis of 1,2-bis(indenyl) hydrocarbyl compounds, typically 1,2-bis(indenyl) alkanes. Pursuant to one aspect of the invention, an indenyl lithenide is treated with a terminal dihaloalkane and tetrahydrofuran (THF) wherein a reaction mixture containing a hydrocarbyl bridged indene is produced. The reaction is illustrated by Equation 1:
Equation 1
DESCRIPTION OF THE INVENTION
In general, the synthesis of hydrocarbyl bridged indenes pursuant to this invention may be accomplished by treating an indenyl alkali metalide compounds of formula XZX, in which Z is any hydrocarbyl and X is any halogen, e.g., chlorine, preferably in a non-interfering medium, preferably diethyl ether and THF. Preferably, Z is —(CH
2
)
n
—; n=1-20.
The indenyl alkali metalide is prepared treating indene with an alkali metal alkyl in an ether medium at a temperature of −10 to −20° C. Alkali metal alkyls useful in this invention have the formula MOR, wherein M is any alkali metal and R is an alkyl group, typically a C
1
to C
10
alkyl group. N-butyllithium is preferred.
The alkali metalide synthesis reaction mixture typically comprises the selected alkali metal alkyl and the ether medium in which it is produced. Hydrocarbyl bridged indenes may be produced by combining a selected terminal dibromoalkane and THF with an appropriate metalide synthesis reaction mixture. Alternatively, the alkali metalide may first be isolated from the reaction mixture in which it is synthesized. According to one embodiment of the invention, the isolated indenide alkali metalide and THF are then reacted with a dibromoalkane, typically at room temperature, wherein a reaction mixture containing a hydrocarbyl bridged indene is produced. No reaction occurs upon combination of the dibromoalkane with the alkali metalide reaction mixture in ethyl ether.
REFERENCES:
patent: 5866706 (1999-02-01), Gately
patent: 6291699 (2001-09-01), Birmingham et al.
Boulder Scientific Company
Irons Edward S.
Shaver Paul F.
LandOfFree
Method for synthesis of hydrocarbyl bridged indenes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for synthesis of hydrocarbyl bridged indenes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for synthesis of hydrocarbyl bridged indenes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2977668