WO2000007968A1

WO2000007968A1 - Coupling reactions of 2-substituted, 7-haloindenes with aryl substituents to produce metallocene catalyst ligands

Info

Publication number: WO2000007968A1
Application number: PCT/US1999/017519
Authority: WO
Inventors: Jeffrey M. Sullivan; Hamlin H. Barnes
Original assignee: Boulder Scientific Company
Priority date: 1998-08-03
Filing date: 1999-08-03
Publication date: 2000-02-17
Also published as: EP1027314A4; US6465700B1; AU5332499A; CA2305363A1; JP2002522405A; EP1027314A1; NZ503655A; AU764843B2

Abstract

Novel 2-substituted 7-haloindenes and methods for synthesizing such indenes are described. The 2-substituted 7-haloindenes may be coupled with any aryl group to produce a metallocene catalyst intermediate.

Description

COUPLING REACTIONS OF 2-SUBSTITUTED, 7-HALOINDENES WITH ARYL SUBSTITUENTS TO PRODUCE METALLOCENE CATALYST LIGANDS

This application is a continuation of Serial No . 09/127,796 filed 03 August 1998 and, in turn, a continuation-in-part of application Serial No. 08/795,019 filed 05 February 1997.

FIELD OF THE INVENTION This invention relates to 2-substituted 7- haloindenes useful in coupling reactions to produce a wide variety of metallocene olefin polymerization catalyst intermediates and to metallocene catalysts derived rom such intermediates .

BACKGROUND OF THE INVENTION Metallocenes which comprise indene systems are well known -olefin polymerization catalysts. Substitution patterns in such indene systems significantly influence poly- -olefin properties , including tacticity and molecular weight.

Spaleck, et al . , Orσanometallies (1994) 13:954-963 describes bridged zirconocene catalysts including indene systems illustrated by Compound 4 of "Scheme 1" (p. 955) which yield highly isotactic polypropylene when used with methylaluminoxane as a cocatalyst. As shown by "Scheme 2", Compound 10, Spaleck's synthesis requires an expensive 2- (bromomethyl) biphenyl starting material.

This invention provides a more cost effective synthesis of metallocene catalysts which comprise indene systems .

DESCRIPTION OF THE FIGURES Figure 1 illustrates a scheme for the synthesis of the Formula I compound, 2-methyl-7-chloroindene. Figure 2 is a NMR spectrum of 2-methyl-7- chloroindene produced by the Figure 2 scheme as shown by Example 1.

Figure 3 illustrates a scheme for the synthesis of the Formula I compound, 2-ethyl-7-chloroindene.

Figure 4 illustrates a scheme for Grignard reagent coupling a Formula I compound to provide a Formula II compound.

SUMMARY OF THE INVENTION One aspect of this invention provides novel 2- substituted, 7-haloindenes of Formula I:

or 1(a), i.e., the same compound to which different, but structurally identical ring position numbers are assigned:

Hereinafter the Formula I position numbers will be used. In Formula I and I (a) , Q is a hydrocarbyl group and X is a halogen, i.e., fluorine, chlorine, bromine or iodine. Q may be an alkyl group R_x which may be any straight or branched chain alkyl group having 1 to 10 carbon atoms . Q may also be any aryl group Ar . Specific Ar groups include phenyl, napthyl and anthracyl groups . Phenyl and substituted phenyl groups are preferred. Substitution may be at any one or more available ring positions by an alkyl group, e.g.,

or by an aryl group or any other substituent including a halogen .

Preferred embodiments of this aspect of the invention are substituted or unsubstituted 2-methyl-7- chloroindene and 2-phenyl-7-chloroindene.

Another aspect of the invention includes coupling of

Formula I indenes with a Grignard reagent having the formula ArMgX to produce the novel compounds of

Formula II :

in which Q and Ar are as defined. The invention accordingly comprises the novel

Formula I and II compounds per se, procedures for the synthesis thereof, procedures for the conversion of

Formula II compounds to intermediates for the production of metallocene catalysts and for the use of such catalysts to polymerize , e.g., an α-olefin .

DETAILED DESCRIPTION OF THE INVENTION

PREPARATION OF FORMULA I COMPOUNDS

Either of two methods, as shown by Examples 1 and 2 and Figures 1 and 3, may be used to prepare Formula I compounds .

THE EXAMPLE 1 METHOD

The starting material for the Example 1 method is a malonic acid diester having the Formula III :

Q

I

III . RjOOC — CH — COOR₃

in which Q (which is the same Q as in the Formula I and II compounds) , R_? and R₃ are the same or optionally different straight or branched chain alkyl groups having 1 to 10 carbon atoms . Alkyl groups specifically useful in this aspect of the invention include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl , nonyl , isononyl , decyl and isodecyl groups . Preferred diesters are methyl or phenyl diethyl malonate in which R is methyl and R₂ and R₃ are ethyl.

The malonic acid diester of Formula III is reacted with an alkali metal hydride MH, in which M is an alkali metal, i.e., lithium, sodium or potassium, to provide an intermediate compound in which the "H" of the Formula III diester is replaced by Z+, e.g., Na+. This reaction is appropriately carried out by adding a 40% to 60% dispersion of an alkali metal hydride in mineral oil to a non-interfering solvent such as tetrahydrofuran (THF) in a reaction vessel positioned in an ice bath. The malonic diester is added slowly while the temperature is maintained below 10°C. Hydrogen evolution is monitored. Upon completion of the addition of the diester, the reaction vessel is removed from the ice bath, and the reaction mixture containing the intermediate compound is stirred, e.g., for about 1 to 4 hours, preferably about 2 hours . When the addition is complete, the reaction mixture containing the intermediate compound and which may contain THF is cooled to a temperature of 0°C to 10°C, preferably 5°C, and a 2-halobenzylhalide, preferably a 2- chloro or 2-bromobenzyl halide, is added over a time period of 0.5 to 1.5 hours to provide a reaction mixture containing a Formula IV compound. This reaction mixture is stirred, preferably at about ambient temperature, for 6 to 15 , pre erably about 12 , hours :

in which X is the halogen substituent, preferably chlorine, of the Formula I compound. The Formula XV diester is saponified by heating, preferably in the presence of THF. The reaction mixture containing the diester is heated and combined with 30% to 60% aqueous alkali metal hydroxide MOH, preferably NaOH, to provide a compound having Formula V:

in which M is as defined.

THF and the alcohols RjOH and R₃OH, which result from saponification of the diester IV, are removed by distillation. The saponification reaction mixture is cooled, and poured into aqueous acid, e.g., 4-6N HC1, with vigorous stirring to produce a compound having Formula VI :

The white solids comprising the Formula VI compound which form are removed by filtration, dried and placed in an appropriate reaction vessel equipped for short path distillation. Heating is applied to melt the solids and thereafter increased to 120°C to 150°C for a period of about 0.5 to 1.5 hours to accomplish decarboxylation and produce a compound of Formula VII :

The melt so produced is cooled to about 50°C, dissolved in a non-interfering solvent, e.g., an aliphatic hydrocarbon solvent having 6 to 9 carbon atoms, preferably heptane, and the Formula VII compound present in the solution is reacted with S0C1₂ at a temperature of 40 to 60°C with stirring to produce a Formula VIII compound:

The temperature of the reaction mixture is thereafter raised to 100°C to 130°C to remove excess S0C1₂ and solvent. The reaction mixture is then cooled to room temperature, a chlorinated hydrocarbon solvent, preferably methylene chloride, is added, and the mixture is cooled to -10°C to 0°C, followed by the addition of aluminum chloride with stirring to produce a compound of Formula IX by Friedel-Craft acylation:

The acylation reaction is quenched by pouring on to ice. The layers which form are separated, and organic layer washed with an aqueous base, preferably sodium bicarbonate. All solvent is removed by distillation, methanol is added, and the reaction mixture containing Formula IX is cooled in an ice bath and combined with sodium borohydride to produce Formula X:

The reaction is quenched with water, and methylene chloride is added to separate the Formula X compound, and the solvent is removed by distillation. The Formula X compound is reacted with paratoluene sulfonic acid (pTSA) in toluene (or other aromatic solvent such as xylene or mesitylene) to afford the desired 2-substituted, 7- haloindene, compound of Formula XI:

Aqueous and organic layers separate upon addition of aqueous sodium bicarbonate. The organic layer is dried over anhydrous Na₂S0₄. Toluene is removed by distillation. EXAMPLE 1 Synthesis of 2-Methyl-7-Chloroindene. This example illustrates the scheme depicted by Figure 1.

A 5L round-bottom flask is equipped with a mechanical stirrer, thermometer and reflux condenser, and swept thoroughly with nitrogen. 2L tetrahydrofuran (THF) is added to the flask and then 116g NaH, 60% dispersion in mineral oil (2.9 mol) . An ice bath is applied to the flask and moderate stirring begun. 506g methyl diethyl malonate (2.9 mol) is added slowly from an addition funnel maintaining the temperature below 10°C. Hydrogen evolution is monitored and vented through a mineral oil bubbler and controlled by the rate of addition of the methyl dimethyl malonate. Once the addition is complete, the cooling bath is removed, and the reaction stirred for 2 hours. The flask is again cooled to 5°C and 367 mL 2-chlorobenzylchloride (2.9 mol) added over 1 hour, then stirred for 12 hours at ambient temperature. Reflux condenser is changed to short path distillation. 520 mL 50% W/v NaOH(aq) and 1500 mL H₂0 is added, then heating begun to distill the THF. Distillation was continued to 100°C with additional water to keep the reaction clear and fluid. Distillation was continued to remove ethanol and water at 100°C for 15-30 minutes. Once cooled, the reaction mixture is poured into 1.5L H₂0 and IL 12N HC1 with vigorous stirring. White solids, which formed immediately, were collected by filtration and dried on the Buchner funnel by aspiration for 15 minutes, then returned to the 5L flask equipped for short path distillation. Heating was applied slowly to melt the solids, and then increased to 135°C for at least 1 hour. C0₂ evolution was monitored by venting through a mineral oil bubbler. The melt was cooled to 50°C and 2L heptane added, then warmed to 45°C, and addition of 265 mL S0C1₂ (3.63 mol) was begun. Adequate venting was provided. After all the S0C1₂ was added, the reaction was stirred for 1.5 hours at 60°C, then heated to 120°C to distill the excess S0C1₂ and all the heptane. The reaction flask was allowed to cool to ambient temperature and 1.5L CH₂C1₂ is added. Cooling was applied to -5° - 0°C, and 465g A1C1₃ (3.5 mol) added in portions . The reaction was stirred at ambient temperature for 2 hours , then quenched by pouring onto 2 Kg ice. The layers were separated, and the organic layer was washed with 500 mL H₂0, and then 250 mL 5% w/v NaHC0₃ (aq) . All the solvent was distilled to a temperature of 70°C. IL methanol was added to the oil, the flask cooled with an ice bath, and a slurry of 56g NaBH₄ (1.5 mol) in 500 mL methanol containing lg NaOCH₃ was slowly added. Hydrogen evolution was monitored by venting through a mineral oil bubbler and controlled by the rate of addition . The reaction was quenched by adding 1.5L H₂0 and 500 mL CH₂C1₂ to separate the product. Solvent was distilled from the separated organic layer up to 70°C. 1.5L toluene was added to the oil and the 5L flask equipped with a Dean-Stark trap. Heating was begun and p- toluene sulfonic acid was added in l-3g portions . The reaction was followed by GC until the dehydration was complete. 1.5L 5% w/v NaHC0₃(aq) was added to the reaction, the layers separated, and the organic layer dried over anhydrous Na₂S0₄. Toluene was distilled under reduced pressure to 90°C and the product, 2-methyl-7- chloroindene , obtained by distillation thorough a 30 cm packed column at 93-5°C at 1-3 mm Hg. Yield was 310g (1.89 mol) , 65%, of a clear, colorless oil b.p. 229°C. Figure 2 was the NMR spectrum of the product. EXAMPLE 1(a) 2-phenyl-7 chloroindene is prepared as described in Example 1 where phenyl diethyl malonate is used in lieu of methyl diethyl malonate. THE EXAMPLE 2 METHOD

The starting material for the Example 2 method for producing Formula I compounds is an alkali metal,

preferably sodium, salt, a carboxylic acid, preferably a fatty acid, e.g., butanoic acid, having the Formula QCOOM (XII) in which Q and M are as defined.

This Formula XII acid is reacted in THF solution with an alkali metal, preferably lithium, diisopropylami.de, to form the intermediate XII:

in which M and M_x are alkali metals , and in which M is preferably lithium and Mj is preferably sodium. The Formula XII compound is reacted with a 2- halobenzylhalide to provide Formula XIII compound:

in which X is a halogen, preferably chlorine or bromine, i.e., the halogen of a Formula I compound.

More speci ically, this series of reactions may be carried out by combining an alkali salt of Formula XII with an alkali metal diisopropylamide, preferably lithium diisopropylamide to produce a compound having the Formula XII in THF solution. The reaction is conducted at ambient temperature and preferably stirred for 24 hours. 2-halo benzylhalide is added to the reaction mixture so produced, and the reaction mixture stirred for an additional time period, preferably 18 to 24 hours. The reaction is then quenched, e.g., by the addition of water. The aqueous layer is neutralized by a mineral acid, e.g., hydrochloric acid, at which point a phase separation occurs. A 2- halobenzyl fatty acid, such as the compound of Formula XIII, is concentrated in the organic layer.

Synthesis of 2-Q-7-chloroindene is completed by the same sequence of reactions as described in Example 1 and shown in Figure 3, beginning with the addition of S0C1₂.

EXAMPLE 2 Synthesis of 2-Ethyl-7-Chloroindene. This example illustrates the scheme depicted by Figure 3.

A 12L round-bottom flask was equipped with a mechanical stirrer, thermometer and reflux condenser.

385g sodium butanoate (3.5 mol) and 2L THF were added to orm a slurry . 2.625L lithium diisopropylamide , 2M in heptane/ THF/ethyl-benzene (5.25 mol, 50% excess) were added at ambient temperature, and then stirred for 24 hours. Then 705g 2-chlorobenzyl chloride (4.375 mol, 25% excess) was added, and the reaction stirred for another 24 hours. Once completed, the reaction was quenched by adding 1500 mL H₂0, and the solution allowed to separate. The aqueous layer , pH=13 , was separated and neutralized by addition of 12N HCl to obtain pH=7.0 , at which point a phase separation occurs. 2- (2-chlorobenzyl) butanoic acid was concentrated in the organic layer. Synthesis of 2- ethyl-7-chloroindene was completed by the same sequence of reactions and method as described in Example 1 , beginning with the addition of S0C1₂. See Figures 1 and 3. The product, 2-ethyl-7-chloroindene, was obtained by distillation at 110-114°C under 1-3 mm Hg. Yield was 205g (33% overall) of a clear, colorless oil.

PREPARATION OF FORMULA II COMPOUNDS As shown by Figure 4 , Formula II compounds are prepared in known manner by reacting a Formula I compound with a Grignard reagent, ArMgX, in which X is as described, preferably Br and Ar is as described, in an ethyl ether solvent containing 1-3-bis (diphenylphosphino) propane nickel II chloride, Ni (dpp) .

Examples 3-6 utilize the synthesis of the Formula II compounds depicted by Figure 4.

EXAMPLE 3 A 5L round bottom flask was equipped with mechanical stirring, a reflux condenser and ice bath. 488.2g distilled 7-chloro-2-methylindene (2.97 mol) was added, dissolved in 2L ether and 32.2g Ni (dpp) (0.059 mol, 2 mol%) slurried in the solution, and stirred to cool to 0- 2°C. 1.05L of 3.1M phenylmagnesium bromide in ether (3.25 mol, 10% excess) was added slowly from an addition funnel so that the temperature remained below 5°C. Once complete, the ice bath was removed, and the reaction stirred up to room temperature. The reaction was refluxed for 8 hours , and checked for completion by GC . The reaction flask was cooled with an ice bath, and 250 mL water added, then IL 10% HCl. The aqueous and organic layers are separated, and the organic layer dried over anhydrous Na₂S0₄. Ether was distilled, and the residual oil placed on a column of lOOg silica gel. Ξlution with hexane was performed, the hexane distilled under reduced pressure to a temperature of 90°C. 2-methyl-7- phenylindene (Spaleck compound 13a) was obtained by distillation at <1 mm Hg with a 36 cm Vigreux column at 125°C. A fore-cut containing biphenyl was obtained at 70-90°C and discarded. Yield was 507.8g (2.47 mol) equal to 80%.

EXAMPLE 3(a) 2-phenyl-7 phenyl indene is prepared in like manner from 2-phenyl 7 chloroindene as produced by Example 1(a) . EXAMPLE 4 A 12L flask equipped as in Example 3 was charged with 661g distilled 2-methyl-7-chloroindene (4 mol), 2.5L ether, and 43.3g Ni (dpp) (0.08 mol, 2 mol%) . 1.75L of 2.6M phenylmagnesium bromide in ether (4.55 mol, 12% excess) was added at 2°C. Following stir-out to ambient temperature and reflux for 8 hours , the reaction was quenched and worked up by the method described in Example 3. Yield of 2-methyl-7-phenylindene (same as 2- methyl- -phenylindene) was 642.7g (3.12 mol) equal to 78%,

EXAMPLE 5 A 5L flask was equipped as in Example 3. 178g 2- ethyl-7-chloroindene (1 mol), IL ether and 10.8g Ni (dpp) (0.02 mol, 2 mol%) added, followed by 355 mL of 3.1M phenylmagnesium bromide in ether (1.1 mol, 10% excess) . A ter quenching and work-up by the method described in Example 3, 176g 2-ethyl-7-phenylindene (0.8 mol) was obtained by vacuum distillation at 140°C in 80% yield.

EXAMPLE 5(a) 2-phenyl-7-napthylindene is prepared in like manner from 2-phenyl-7-σhloroindene (see Example 1(a)) and naphthyl magnesium bromide . EXAMPLE 6 A 5L flask was equipped as described in Example 3. 164g 2-methyl-7-chloroindene (1 mol) 500 mL ether and 10.8g Ni(dpp) added. 2L of 0.5M naphthyl magnesium bromide in ether was added at 20°C. The reaction was stirred vigorously at reflux for 12 hours , then quenched and worked up as described in Example 3. 184.3g 2-me hy1- 7- (1-naphthyl) indene (Spaleck compound 21) (0.72 mol) was obtained by recrystallization from heptane in 72% yield.

METALLOCENE CATALYSTS The Formula II compounds of this invention may be converted to metallocene α-olefin polymerization catalysts in the manner illustrated by Spaleck' s Schemes 1 and 2 and in U.S. Patents 5,278,264 and 5,786,432. Such catalysts may have, for example, the formula

/ ^Jl \

^L M²X₂

\ /

J₂ wherein _r and J₂ are the ligands from same or different Formula II compounds, L is -SiY₂- in which Y is an alkyl group preferably having 1 to 5 carbon atoms or - (CH₂) _n- in which n is 1 to 4 atoms, M² is Zr, Hf or Ti and X is a halogen, preferably chlorine. -SiY₂- is preferably -(CH₃)₂ Si- and MaXj is preferably ZrCl₂.

Example 7 illustrates one such conversion.

EXAMPLE 7 A IL flask was charged with toluene (300 mL) , THF

(15g, 0.2 mol) and 2-methyl-7-naphthyl-indene (same as 2- methyl-4-napthyl indene) (52g, 0.2g) . The contents were cooled to -20°C and 1.6 M butyl lithium in hexane (125 mL) was slowly added. This mixture was warmed to 25°C and stirred for four hours. The contents were cooled to -20°C and dimethyldichloro-silane (12.9g, 0.1 mol) was added. This reaction mixture was warmed to 25°C and stirred for twenty- our hours . Distill the reaction mixture under reduced pressure to pot temperature of 45°C. Allow the reaction to cool to ambient temperature and add ether (15g, 0.2 mol) . The reaction mixture was then cooled to -20°C and 1.6 M butyl lithium in hexanes (125 mL, 0.2 mol) was slowly added. This reaction mixture was slowly warmed to 25°C and stirred for twenty-four hours. Cool the reaction to -30°C and add zirconium tetrachloride , ZrCl₄ (23.2g, 0-1 mol) . The reaction is allowed to warm to ambient temperature and stirring continued for another twelve hours.

The reaction mixture was then filtered and the solids were washed with hexane. The solids were dried under vacuum. The dry solids were dissolved in dichloromethane (800 mL) and this solution filtered through a small bed of celite to remove lithium chloride. The volume was reduced to 100 mL by solvent removal. The filtered crystals were washed with 10-15 mL dichloromethane and then dried in vacuum. The retained yield—60-80g 2 methyl-7-naphthy1- indene-Si (CH₃) ₂ 7-napthyl-2-methyl indene.

EXAMPLE 7(a) The 2-methyl-7-phenyl analog is produced in like manner from 2-methyl-7 phenylindene.

EXAMPLE 7(b) In like manner 2-aryl-4-aryl ansa metallocenes may be prepared. Such metallocenes may include 2-phenyl-7- phenylindene Si (CH₃) ₂-7-phenyl-2-phenylindene .

Claims

CLAIMS :

A compound having the formula:

X

in which X is a halogen and Q is a hydrocarbyl group.

2. A claim 1 compound in which Q is an aryl group .

3. A claim 1 compound in which X is chlorine and is phenyl or napthyl.

4. A compound having the formula:

5. The method comprising reacting a compound having Formula I with ArMgX in which Ar is any aryl group and X is a halogen wherein a compound having Formula II is produced.

6. The claim 5 method in which Ar is a phenyl , a napthyl or a 9-fluorenyl group.

7. The claim 5 or claim 6 method in which X is chlorine or bromine or fluorine.

8. A method for synthesizing a compound having Formula I which comprises:

(i) reacting a malonic acid diester with an alkali metal hydride and a 2-halobenzylhalide to produce a compound having Formula IV; (ii) saponifying said compound having Formula

IV to produce a compound having Formula V;

(iii) converting said compound having Formula V to a compound having Formula V I;

(iv) reacting said compound having Formula VII with S0C1₂ to produce a compound having Formula VTII; (v) reacting said compound having Formula VIII with aluminum chloride to produce a compound having Formula IX;

(vi) reacting said compound having Formula IX with sodium borohydride to produce a compound having Formula X; and (vii) reacting said compound having the

Formula X with paratoluene sulfuric acid to produce said compound having Formula I .

9. The claim 8 method in which: (i) said malonic acid diester of step (i) has the Formula III; and

(ii) the alkali metal hydride of step (i) is sodium hydride, and the halobenzylhalide of step (i) is 2-chlorobenzyl chloride.

10. A method which comprises :

(i) reacting an alkali metal salt of a fatty acid having 1 to 10 carbon atoms with an alkali metal hydride to produce a first reaction mixture containing an intermediate compound; and (ii) combining said step (i) reaction mixture with a 2-halobenzylhalide to convert said intermediate compound into a compound having the

Formula XIV.

11 . The method which comprises reacting a compound having the formula :

in which is a hydrocarbyl group with ArMgBr wherein a reaction mixture containing a compound having the Formula

is produced.

12. The claim 11 method in which ArMgBr is phenyl magnesium bromide or napthyl magnesium bromide.

13. The claim 11 method in which Q in the compound having the formula:

is phenyl or napthyl.

14. The claim 11 method in which in the compound having the formula:

is methyl and ArMgBr is phenyl MgBr.

15. A method which comprises reacting 7-chloro-2- phenylindene with naphthyl magnesium bromide, wherein a reaction mixture containing 7-naphthyl 2-phenylindene is produced.

16 . The claim 15 method in which said 7-naphthyl-2- phenylindene is separated rom said reaction mixture .

17. A method which comprises

(i) reacting a compound having Formula I with ArMgX in which Ar is phenyl, napthyl or anthracyl groups and X is a halogen wherein a compound having Formula II is produced; and (ii) converting said compound of Formula II produced in step (i) to a compound having the formula

Jl>

Y₂Si M²Z

wherein J_t and J₂ are the same or different Formula II compound residues , Y is an alkyl group, M² is a group IV metal and Z is chlorine, bromine, fluorine or iodine.

18. The claim 17 method wherein Y is methyl and Z is chlorine .

19. A compound having the formula:

in which is a hydrocarbyl group and Ar is an aryl group .

20. A compound having the formula:

21 . A method which comprises :

(i) reacting a compound having the formula (a) :

with phenyl magnesium bromide wherein a reaction mixture containing a compound having the formula (b)

is produced.

22. The claim 21 method further comprising a step (ii) :

(ii) converting said step (i) compound of formula (b) to a metallocene of formula (c) :

(b)

(c) MX,

^'(b) wherein L is -Si (Y₂) - in which Y is an alkyl group or (CH₂)_n in which n is 1 to 4, M is Zr, Hf or Ti and X is a halogen.

23. A method for producing 2-methyl-4-phenylindene which comprises

(i) reacting 2-methyl-4-chloroindene with phenyl Grignard reagent wherein a reaction mixture containing 2-methyl-4-phenylindene is produced; and

(ii) converting said 2-methyl-4-phenylindene of step (i) to a metallocene having the formula

in which L is -Si (Y) ₂ in which Y is an alkyl group having 1 to 5 carbon atoms, M is Zr, Hf, or Ti and X is a halogen.

24. A method for synthesizing 2-methyl-4- phenylindene which comprises:

(i) reacting a compound having

with phenyl magnesium bromide wherein a reaction mixture containing said 2-methyl-4-phenylindene is produced.

25. The claim 24 method further comprising: (ii) converting said 2 methyl-4-phenylindene from step (i) into bis (2-methyl-4-phenyl) zirconium.

26. The claim 24 method further comprising converting said 2-methyl-4-phenylindene from step (i) into rac-dimethylsilylbis (2-methyl-4-phenyl indenyl) zirconium dichloride.