KR20220029541A - Novel synthetic process for C2 bridged cyclopentadienyl ligands and corresponding ansa-metallocene catalysts - Google Patents

Abstract

The present invention is a novel method for synthesizing C2 (ethylene) bridged cyclopentadienyl ligands having the formula I and ultimately forming the corresponding ansa-metallocene catalysts therefrom which can potentially be used in various olefin polymerization reactions, An improved efficient process relates to:

Description

Novel synthetic process for C2 bridged cyclopentadienyl ligands and corresponding ansa-metallocene catalysts

The present invention relates to the development of a novel process for synthesizing C2 cross-linked metallocene catalysts for the polymerization of ethylene or for the copolymerization of ethylene or for the polymerization of propylene. More specifically, the present invention is a novel and novel method for synthesizing C2 (ethylene) bridged cyclopentadienyl ligands and ultimately forming the corresponding ansa-metallocene catalysts that can potentially be used in a variety of olefin polymerization reactions. , to an improved and efficient process.

Metallocene-based catalysts for olefin polymerization offer significant advantages over traditional Ziegler-Natta (Z-N) catalysts. Due to its single-site character it provides greater comonomer inclusion (more than 20%) and thus has better flexibility, better film transparency, and improved dart and impact properties compared to products made from traditional ZN catalysts. provides The uniform comonomer distribution of the polymer backbone often leads to a sharper and narrower melting point range required in heat seal packaging applications. Metallocene based catalysts have improved activity, uniform comonomer distribution in the polymer backbone and more in the presence of a boron based cocatalyst or with a suitable cocatalyst such as methylaluminoxane or MAO (hydrolysis product of TMA and water) and more Polymers with better steric regulatory control can be produced.

W. Kaminsky et. al.: Angew. Chem., 1980, 92, 396; W. Kaminsky et. al.: Makromol. Chem., Rapid Commun. 5, 225 (1984); W. Kaminsky et. al.: Naturwissenschaften 71, 93 (1984); W. Kaminsky et. al.: Angew. Chem. 97, 507 (1985); W. Kaminsky et. al.: Makromol. Chem. 193, 1643-1651 (1992); and W. Kaminsky et. al.: Macromol. Chem. Phys., 1996, 197, 3907 for the first time disclosed metallocene catalysts for use with methylaluminoxane (MAO) cocatalysts for the polymerization of different olefins. These papers further describe the synthesis of a majority of symmetric and chiral zirconocenes that give custom polymers of entirely different structures. Moreover, single site catalysts have shown the ability to allow users to more efficiently control polymer stereoregularity, molecular weight and molecular weight distribution. Moreover, in addition to homopolymers of polyethylene and poly(propylene), new classes of copolymers and elastomers have been synthesized.

Prof H. H. Brintzinger et.al: J. Organomet. Chem., 1982, 232, 233 for the first time the synthesis of a chiral ethylene (C2) crosslinked ansa metallocene complex [ethylene-crosslinked bis(indenyl) precursor] and better stereoregularity control and improved isotropy. Its beneficial use in the polymerization of propylene with carbon dioxide has been disclosed. Although currently the most important use for ansa-metallocene catalysts is for the polymerization of olefins such as ethylene and propylene, they also find important use as catalysts or catalyst precursors for other reactions where stereoregularity is important. The usefulness of ansa-metallocene complexes as catalysts for olefin polymerization and other reactions has created a high demand for the practical synthesis of ansa-metallocene compounds, especially for isotropic polypropylene and ethylene α-olefin copolymerization.

Prior art, such as EP0754698, US6100416, is a C2 (ethylene) bridged cyclopendye, which provides stereochemical control in the polymerization of propylene, more specifically, which is widely used as a homogeneous ansa-metallocene catalyst for the polymerization of olefins. Disclosed are metallocene compounds having a nyl group. Asymmetric ethylene-bridged metallocene complexes with Group 4 metals containing fluorenyl and indenyl fragments have also been proposed by the prior art for the polymerization of propylene.

US5191132; US006100416A; WO2015147215A1; WO2009081792A1; Rieger et. al.: Organometallics, 1994, 13, 647-653; Walter Kaminsky et. al.: J. Chem. Soc., Dalton Trans., 1998, 0, 1413-1418; Thomas E. J et. al.: Organometallics 1999, 18, 1439-1443; B. Ulf Dietrich et. al.: J. Am. Chem. Soc. 1999, 121, 4348-4355; Richard Lai et. al.: Some other prior art, such as Dalton Trans., 2013, 42, 7980-7990, have some routes for synthesizing ethylene-bridged indenyl or fluorenyl metallocenes based on the following schematic principle. report:

(a) a lithium salt of an indenyl or fluorenyl moiety is reacted with 1,2 dibromoethane (or 2-bromoethane indenyl or fluorenyl) to form the respective ethylene-bridged metallocene precursor Create or:

(Cp ¹ is Cp or Ind or Flu)

or

(b) a lithium salt of an indenyl or fluorenyl moiety is reacted with ethylene oxide to form a 9-hydroxyethylfluorene type moiety which is then trifluoromethane sulfonic anhydride (or p-toluenesulfonyl chloride) to replace the hydroxyl group with an OTf (or OTs) group, whereby the OTf (or OTs) derivative is finally reacted with indenyllithium to produce an ethylene-crosslinked metallocene precursor:

However, it was observed that the above reported route for synthesizing ethylene-bridged indenyl or fluorenyl metallocene precursors suffers from the following disadvantages:

(i) Incorporation of ethylene bridges in ethylene bis(tetrahydroindene) [Ref: R.L. Halterman et al.: Journal of Organometallic Chemistry 604 (2000) 12-19] reaction of lithium salts of indenyl or fluorenyl moieties with additional 1,2-dibromoethane, as shown below, with competitive intramolecular cyclization It is reported to be even more problematic due to the formation of non-essential spiro-cyclopropane by-products that form as by-products in:

The formation of such non-essential spiro-cyclopropane by-products disadvantageously results in the formation of the final metallocene compound in significantly lower yields (about 14%);

(ii) it is also noted that such a reaction requires the excessive use of the starting material indene which makes the process expensive; The use of ethylene oxide as a reagent is harmful to the environment; The fluorenyl/indenyl intermediate (OTf) formed is very unstable and therefore cannot be isolated. [Reference: B. Rieger et. al.: Organometallics 1994, 13, 647-653; Richard Lai et. al.: Dalton Trans., 2013, 42, 7980-7990].

Therefore, the ethylene crosslinked (C2 crosslinked) ansa metallocene, which essentially avoids the formation of the above-mentioned unwanted by-product spiro-cyclopropane, which in turn may provide a better "final product" in higher yields There remains a need in the art to develop superior processes for synthesizing precursors and subsequently their C2 cross-linked ansa metallocene catalysts (hereinafter also may be referred to as "final products").

Accordingly, the inventors of the present invention have sought to overcome the above disadvantages of the previously reported process; and synthesizing an ethylene crosslinked (C2 crosslinked) ansa metallocene precursor and subsequently synthesizing the "final product" to produce its industrially scalable C2 crosslinked ansa metallocene catalyst in superior quality and quantity. We have developed a new, improved, economical and efficient route for

The object of the invention is to overcome the disadvantages of the prior art.

Another object of the present invention is to provide a novel process for preparing an ethylene crosslinked (C2 crosslinked) ansa metallocene precursor (ligand) with a yield of 70 to 90%.

Another object of the present invention is to provide a novel process for preparing an industrially scalable C2 cross-linked ansa metallocene catalyst having a yield of 70 to 85%.

Another object of the present invention is to provide a novel, improved process for synthesizing C2 crosslinked ansa metallocene precursors and catalysts thereof, wherein the scope of the formation of unwanted impurities such as spiro-cyclopropane is none.

Another object of the present invention is also to provide a novel process for synthesizing environmentally friendly C2 crosslinked ansa metallocene precursors and catalysts thereof.

One aspect of the present invention provides a novel and improved process for synthesizing C2 (ethylene) bridged cyclopentadienyl ligands having the general formula (I):

wherein R1 to R8 are the same or different and at each occurrence H, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C10 alkenyl, substituted or unsubstituted C1-C10 alkynyl , substituted or unsubstituted C1-C12 heterocyclyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1-C12 aromatic ring system, silyl, alkylsilyl; any two consecutive groups from R1 to R8 may together form a substituted or unsubstituted aromatic, partially saturated or saturated fused ring system with or without a heteroatom selected from N, O, S;

The process is:

(a) reacting a halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;

(b) reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;

(c) another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt in the presence of a saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst, as described above in step (b). adding to the aldehyde intermediate to form a fulvene derivative; next

(d) reducing the fulvene derivative with a reducing agent to form a C2 (ethylene) bridged cyclopentadienyl ligand;

wherein the process essentially avoids the formation of any unwanted spiro-cyclopropane impurities.

Another aspect of the present invention provides a novel and improved process for synthesizing a C2 (ethylene) crosslinked ansa metallocene catalyst comprising the steps of:

(e) reacting the halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;

(f) reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;

(g) another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt in the presence of an essentially saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst in step (b) adding to the aldehyde intermediate of to form a fulvene intermediate;

(h) reducing the fulvene derivative with a reducing agent to form a C2 (ethylene) bridged cyclopentadienyl ligand; next

(i) lithiating the C2 (ethylene) bridged cyclopentadienyl ligand with a lithiating agent; and

(j) reacting the lithiated ligand with MCl4 to form an ansa metallocene catalyst, wherein M is preferably a transition metal selected from Ti, Hf and Zr, preferably Zr.

Another aspect of the present invention provides an improved process for synthesizing a C2 cross-linked ansa metallocene catalyst comprising the steps of:

(k) reacting the halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;

(l) reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;

(m) another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt of step (b) in the presence of a saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst. adding to the aldehyde intermediate to form a fulvene intermediate; next

(n) adding a lithiating agent and MCl ₄ directly to the fulvene intermediate to form an ansa metallocene catalyst, wherein M is preferably a transition metal selected from Ti, Hf and Zr, preferably Zr.

Another aspect of the present invention provides an ansa metallocene catalyst produced by a process as claimed in any of the preceding claims, having the structure II:

in the formula,

R1 to R8 are the same or different and at each occurrence are H, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C10 alkenyl, substituted or unsubstituted C1-C10 alkynyl, substituted independently selected from substituted or unsubstituted C1-C12 heterocyclyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1-C12 aromatic ring systems, silyl, alkylsilyl; any two consecutive groups from R1 to R8 may together form a substituted or unsubstituted aromatic, partially saturated or saturated fused ring system with or without a heteroatom selected from N, O, S;

M represents one of groups 3 to 12 of the Periodic Table of the Elements, preferably a transition metal selected from Ti, Zr and Hf;

X is independently selected from the group consisting of a hydrocarbyl radical having 1 to 20 carbon atoms, hydride, amide, alkoxide, sulfide, phosphide, halide, diene, amine, phosphine, ether, and combinations thereof and two X's include those that may form part of an aromatic or non-aromatic fused ring or ring system;

R9 and R10 are the same or different and at each occurrence are H, Si, alkylsilyl, substituted or unsubstituted C1-Cl2 alkyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1- independently selected from C10 alkenyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl.

The above aspects, features, and advantages of specific exemplary embodiments of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
1 shows 1H NMR data confirming the formation of intermediate 2-(9H-fluoren-9-yl)-propionic acid ethyl ester ;
Figure 2 depicts 1H NMR data confirming the formation of the intermediate 2-(9H-fluoren-9-yl)-propionaldehyde ;
Figure 3 shows 1H NMR data confirming the formation of intermediate 9-(2-cyclopenta-2,4-dienylidene-1-methyl-ethyl)-9H-fluorene ;
Figure 4 depicts 1H NMR data confirming the formation of C2 bridged Cp ligand 9-(2-cyclopenta-1,3-dienyl-1-methyl-ethyl)-9H-fluorene ;
5 shows the desired ansa metallocene catalyst, i.e. dichloro-[9-(2-cyclopenta-1,3-dien-1-yl-1- methyl -ethyl)fluoren-9-yl]-methyl- 1H NMR data confirming the formation of zirconium is shown;
6 shows 1H NMR data confirming the formation of intermediate 2-(9H-fluoren-9-yl)-butyric acid ethyl ester ;
Figure 7 depicts 1H NMR data confirming the formation of intermediate 2-(9H-fluoren-9-yl)-butyraldehyde ;
Figure 8 shows 1H NMR data confirming the formation of intermediate 9-(1-cyclopenta-2,4-dienylidenemethyl-propyl)-9H-fluorene ;
9 depicts 1H NMR data confirming the formation of the Cp ligand 9-(1-cyclopenta-2,4-dienylmethyl-propyl)-9H-fluorene ;
10 shows the formation of an ansa metallocene catalyst, namely dichloro-[9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium . 1H NMR data confirming the is shown.

The following description, with reference to the accompanying drawings, is provided to provide a general understanding of the illustrative embodiments of the invention. It includes various specific detailed descriptions to aid such understanding, but these should be regarded merely as examples.

Accordingly, those skilled in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and configurations are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited in their bibliographical meaning, but may be used by the inventor simply to enable a clear and concise understanding of the invention. Accordingly, to those skilled in the art, the following description of exemplary embodiments of the present invention is provided for purposes of illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. it should be clear

Terms referring to the singular are to be understood to include the plural, unless the context clearly indicates otherwise.

Features described and/or illustrated in connection with one embodiment may be used in the same or similar manner as in one or more other embodiments and/or may be used in conjunction with or instead of features of another embodiment.

The term "comprises/comprising" as used herein is taken to specify the presence of a described feature, integer, step, or element, but the presence or addition of one or more other features, integers, steps, elements, or groups thereof. It should be emphasized that the exclusion of

As used herein, the term "ansa metallocene" refers to a cross-linked metallocene, wherein cyclopentadienyl (Cp) rings are linked by chemical cross-linking such as ethylene, propylene, and the like.

As used herein, the term "C2 bridged ansa metallocene" refers to a metallocene in which cyclopentadienyl (Cp) rings are essentially linked by an ethylene bridge.

As used herein, the term "improved process" refers to a process for preparing C2 crosslinked ansa metallocene precursors and their catalysts without forming any unwanted by-products such as spiro-cyclopropane.

The term "higher/superior yield" as used herein refers to the synthesis of C2 crosslinked ansa metallocene precursors and their catalysts in 70-85% yield.

The term "THF" as used herein is tetrahydrofuran.

As used herein, the term “Et ₂ O” is ethyl ether.

As used herein, the term “EtOAc” is ethyl acetate.

As used herein, the term "DCM" is dichloromethane.

As used herein, the term “MeOH” is methanol.

The term "MAO" as used herein is methylaluminoxane.

The present invention relates to a novel, improved and economical process for preparing an ethylene (C2) crosslinked ansa metallocene precursor (A) represented by the general formula (I) and its catalyst (B):

in the formula,

R1 to R8 are the same or different and at each occurrence are H, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C10 alkenyl, substituted or unsubstituted C1-C10 alkynyl, substituted independently selected from substituted or unsubstituted C1-C12 heterocyclyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1-C12 aromatic ring systems, silyl, alkylsilyl; any two consecutive groups from R1 to R8 may together form a substituted or unsubstituted aromatic, partially saturated or saturated fused ring system with or without a heteroatom selected from N, O, S;

M represents one of groups 3 to 12 of the Periodic Table of the Elements, preferably a transition metal selected from Ti, Zr and Hf;

X is independently selected from the group consisting of a hydrocarbyl radical having 1 to 20 carbon atoms, hydride, amide, alkoxide, sulfide, phosphide, halide, diene, amine, phosphine, ether, and combinations thereof and two X's include those that may form part of an aromatic or non-aromatic fused ring or ring system;

R9 and R10 are the same or different and at each occurrence are H, Si, alkylsilyl, substituted or unsubstituted C1-Cl2 alkyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1- independently selected from C10 alkenyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl,

The process essentially avoids the formation of any unwanted by-products and/or impurities such as spiro-cyclopropane.

Therefore, according to the present invention, the overall process for synthesizing the C2 cross-linked ansa metallocene precursor and its catalyst is outlined in Scheme 1 below:

plan 1

The processes currently developed have been further embodied in many different forms and should not be construed as limited to the description presented herein.

Embodiments of the present invention provide a novel, improved, economical and easily scalable process for preparing C2 crosslinked ansa metallocene precursors/Cp ligands in 70-90% yield.

In a further specific embodiment, each step of the process currently developed for synthesizing a C2 cross-linked ansa metallocene precursor/Cp ligand and the reaction conditions involved are described in detail below:

· Total reaction conditions included:

All reactions are performed using standard techniques such as the Schlenk technique under an argon (Ar) atmosphere. Methylaluminoxane (MAO) was procured from an external company as a solution in 7% toluene and used as received. All other reagents were purchased from external companies and used without further purification. Toluene, diethyl ether, tetrahydrofuran (THF), and pentane are distilled from sodium (Na) under Ar. Dichloromethane (DCM) is distilled from calcium hydride (CaH ₂ ) under Ar. 1H NMR spectra are recorded by a commercially known NMR spectrometer.

· Step-by-step process:

The currently developed process for synthesizing C2 cross-linked ansa-metallocene complexes essentially comprises the following steps (a-d):

Step (a): Preparation of ester compound (X)

According to the present invention, an amount of 1-1.2 equivalents of a base selected from butyl lithium (BuLi) or potassium tert-butoxide is substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) (1 equivalent) in a solvent such as THF. ) is added for 1 hour under stirring at RT (room temperature) at a temperature of about -78°C to 0°C. A halo-ester selected from bromo-ester or chloro-ester is then dissolved in a solvent such as THF and added dropwise to the reaction mixture at -78°C to 0°C. The reaction mixture is then stirred at room temperature (RT) for approximately 16-18 hours. After completion of the reaction [monitored by thin film chromatography (TLC)], the reaction mixture is quenched with ammonium chloride (NH ₄ Cl) solution and extracted with ethyl acetate. The organic layer is washed with brine, dried over sodium sulfate and evaporated. The resulting crude is purified by column chromatography (0-10% ethyl acetate/hexanes) to obtain the desired ester intermediate (X) in 75-85% yield.

Step (b): Preparation of aldehyde (Y)

According to the invention, 25% of a reducing agent selected from diisobutylaluminum hydride (DIBALH) in an amount of 1-1.2 equivalents in toluene is -78 in a stirred solution of the ester (1 equivalent) in a solvent such as DCM or toluene. It is added at °C and stirred at -78 °C for 1 h. The reaction is quenched with methanol (MeOH) and extracted with DCM. The organic layer is washed with water and brine. The organic layer is then dried over sodium sulfate and evaporated to give the desired aldehyde in 80-90% yield. This aldehyde intermediate (Y) thus formed is used in the next step (c) without further purification.

Step (c): Preparation of cyclopenta-1, 3-diene or 'Compound 1A'

According to the present invention, another previously substituted or unsubstituted cyclopentadiene ( Cp ² ) (1-3 equiv) is dissolved in a stirred solution of an aldehyde (1 equiv) in methanol (MeOH) at 0-5° C. added and stirred at this temperature for 5 minutes at this temperature with a saturated cyclic secondary amine, preferably a saturated secondary N-heterocycle as catalyst selected from pyrrolidine, piperidine, at this temperature, morpholine (0.02 to 0.05 equiv) is added to the reaction mixture at 0-5 °C. The reaction mixture is allowed to rise to RT and stirred again for 3-12 h. Methanol is evaporated and the residue is dissolved in ethyl acetate and washed with water and brine. The organic portion is then dried over sodium sulfate and evaporated. The resulting crude is purified by column chromatography to obtain the desired product "Compound 1A " in 5-90% yield.

Step (d): Preparation of the desired Cp ligand or “Compound 1B”

According to the present invention, lithium aluminum hydride (LAH) (1-1.2 equivalents) is added at 0° C. to a stirred solution of the above fulvene derivative in ether and the reaction mixture is stirred at 0° C. for 1 hour. Excess LAH is quenched by using sodium sulfate decahydrate. The precipitate thus formed is filtered, washed with ethyl acetate and purified by column chromatography (hexane) to obtain the desired C2 cross-linked ansa metallocene precursor/Cp ligand [referred to herein as “Compound 1B” ] to 85-90 % yield.

As used herein, the "cyclopentadienyl (Cp) moiety" is selected from cyclopentadiene, fluorene, and indene.

Another embodiment of the present invention provides a method for preparing a C2 cross-linked ansa metallocene catalyst, comprising the steps of:

i. Lithation of compound 1A (Cp ligand) by reacting "Compound 1A" (Cp ligand) synthesized as above with a lithiating agent selected from lithium triethylborohydride at 0° C. and stirring at room temperature (rt) for 12 hours forming a salt;

ii. filtration of the precipitated lithium Cp ligand, followed by washing with diethyl ether and vacuum drying to obtain each lithium Cp ligand as a white powder; next

iii. The lithiated salt of compound 1A (Cp ligand ) was reacted with n-butyl lithium (nBuLi) and MCl ₄ (M is a transition metal preferably selected from Ti, Hf, Zr) in toluene at -78°C and further stirring for 12 hours;

iv. evaporating the reaction mixture to dryness by placing the reaction mixture in a reagent such as chloroform; then

v. removing excess solvent lithium chloride (LiCl) by filtration over a pad of celite; next

vi. The crude metallocene dichloride thus formed is purified and recrystallized by repeated washing with reagents such as pentane, toluene and/or mixtures thereof to obtain the desired ethylene (C2) cross-linked ansa metallocene catalyst complex (yield: 70-85 %) to create a step.

The formed metallocene complex is then further analyzed by NMR and other elemental analysis.

Therefore, another specific embodiment of the present invention provides a process for preparing a C2 cross-linked ansa metallocene catalyst comprising the steps of:

i. 1 equivalent of "Compound 1A" synthesized as described above was reacted with lithium triethylborohydride [LiEt ₃ BH] (1.5 equivalents, 1 M in THF) at 0 ° C. at room temperature (rt) for 12 hours under stirring. step;

ii. filtration of the precipitated lithium Cp ligand, followed by washing with diethyl ether and vacuum drying to obtain each lithium Cp ligand as a white powder; next

iii. The lithiated salt of compound 1A (Cp ligand ) and another 1.1 equivalents of n-butyl lithium (nBuLi) in toluene are slowly reacted with 1 equivalent of ZrCl4.2THF at -78°C and stirred for an additional 12 hours. ;

iv. evaporating the reaction mixture to dryness by placing it in CH ₂ Cl ₂ ; then

v. removing excess solvent LiCl by filtration over a pad of Celite; next

vi. The crude metallocene dichloride thus formed was purified by repeated washing with pentane, and recrystallized from a toluene/pentane mixture to obtain a white solid compound of an ethylene (C2) cross-linked ansa Zr metallocene catalyst complex (yield: 73%) step to create.

Another embodiment of the present invention provides a process for preparing a C2 cross-linked ansa metallocene catalyst comprising the steps of:

i. reacting 1 equivalent of "Compound 1B" synthesized as described above with n-butyl lithium in toluene at -78°C under nitrogen (N ₂ ) atmosphere;

ii. raising the reaction mixture to room temperature over 2 hours and subsequently cooling to -78°C; next

iii. adding 1 equivalent of MCl ₄ .2THF (M is a transition metal preferably selected from Ti, Hf, Zr) to the reaction mixture to form a colored suspension;

iv. raising the suspension to room temperature with stirring overnight and finally passing through celite;

v. washing the remaining solid reaction with toluene; next

vi. concentrating the remaining filtrate under reduced pressure; and

vii. Washing the sticky solid with hexane, withdrawing the hexane layer with a syringe and drying the solid part under reduced pressure to obtain the desired ethylene (C2) crosslinked ansa metallocene catalyst complex (yield: 70-85%).

The formed metallocene complex is then further analyzed by NMR and elemental analysis.

Therefore, another specific embodiment of the present invention provides a process for preparing a C2 cross-linked ansa metallocene catalyst comprising the steps of:

i. adding 2.1 equivalents of n-butyl lithium to a stirred solution of compound 1B (1 equivalent) synthesized as above in a mixture of toluene and dioxane at -78° C. under a nitrogen (N ₂ ) atmosphere;

ii. raising the reaction mixture to room temperature over 2 hours and then continuing to cool to -78°C;

iii. adding ZrCl4.2THF (1 eq) to the reaction mixture to form an orange suspension;

iv. raising the orange suspension to room temperature with stirring overnight to change the color of the suspension to light brown; and finally

v. passing the suspension of step (iv) through celite and washing the remaining solid fraction with toluene; next

vi. concentrating the remaining filtrate under reduced pressure; and

vii. The yellow sticky solid thus obtained was washed with hexane to obtain the desired ethylene (C2) crosslinked Zr ansa metallocene catalyst as a white solid product (356 mg, yield: 65-73%).

The invention is now illustrated by way of non-limiting examples. The examples are intended purely to illustrate the invention, and therefore should not be construed as limiting the invention in any way.

Example:

Example 1: Preparation of dichloro-[9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium ansa metallocene catalyst

Example 1 is dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium for preparing an ansa metallocene catalyst The process is illustrated.

실험 부분:

Experimental part:

In the present invention, all syntheses are performed under argon using standard Schlenk techniques. Hydrocarbons and ethereal solvents are purified by standard methods. Deuterated solvents C ₆ D ₆ (Cambridge Isotopes, 99.5%) and CDCl3 (Aldrich, 99.8%) are dried over activated 4A molecular sieves.

Starting materials are, for example, ZrCl ₄ (Aldrich), n BuLi (Aldrich, 1.6 M in hexanes), methylaluminoxane (MAO) (Aldrich), and ¹ H-NMR analysis is performed on a Bruker 400 MHz instrument at 25° C. All operations are performed in a dry nitrogen atmosphere, using conventional techniques necessary for the handling of air-sensitive compounds.

단계 1- 2-(9 H -플루오렌-9-일)-프로피온 산 에틸 에스테르의 합성

Step 1- Synthesis of 2-( 9H- fluoren -9-yl)-propionic acid ethyl ester

o Course:

To a stirred solution of 9 H -fluorene (10 g, 60.24 mmol) in THF (100 mL) is added potassium tertbutoxide (7.43 g 66.26 mmol) at 0°C. Keep it stirred at room temperature for 2 hours. Then ethyl 2-bromopropanoate (11.99 g 66.26 mmol) in THF (150 ml) is added to the reaction mixture dropwise at 0°C. The reaction mixture is kept stirring at room temperature for 16 hours. Then the reaction mixture is extracted with EtOAc (100 ml). The organic layer is washed with water and brine solution. The organic portion is dried over sodium sulfate and evaporated to give the crude. The crude is purified using column chromatography to give the pure compound 2-(9H- fluoren -9-yl)-propionic acid ethyl ester in 81% yield.

o Results:

The accompanying Figure 1 shows the results of a ¹ H NMR (CDCl ₃ ) study, confirming the formation of the pure compound 2-(9 H -fluoren-9-yl)-propionic acid ethyl ester: 7.74 (d, 2H) , 7.49 (d, 1H), 7.37-7.25 (m, 5H) 4.53 (s, 1H), 4.31 (d, 2H), 3.28 (m, 1H), 1.34-1.30 (t, 3H), 0.63 (d, 3H).

단계 2- 2-(9 H -플루오렌-9-일)-프로피온알데하이드의 합성

Step 2- Synthesis of 2-( 9H- fluoren -9-yl)-propionaldehyde

o Course:

To a stirred solution of 2-(9 H -fluoren-9-yl)-propionic acid ethyl ester (13.5 g 93 mmol) in DCM (300 mL), diisobutylaluminum hydride (DIBAL-H) (63.2 ml, 25% in toluene) is added at -78°C. It is stirred at -78°C for 1 hour. The reaction was quenched with MeOH (30 ml); Then extracted with DCM (250 ml). The organic layer is washed with water (2x100ml) and brine solution (2x100ml). The organic layer is dried over sodium sulfate and evaporated to give the crude. The crude is purified by column chromatography (hexane) to obtain pure 2-(9H- fluoren -9-yl)-propionaldehyde in 87% yield.

o Results:

The accompanying Figure 2 shows the results of a ¹ H NMR (CDCl ₃ ) study, confirming the formation of the pure compound 2-(9 H -fluoren-9-yl)-propionaldehyde: 9.91 (s, 1H), 7.76 (d, 2H), 7.49 (d, 1H), 7.40-7.30 (m, 4H), 7.27 (s, 1H), 4.57 (s, 1H), 3.25-3.19 (m, 1H), 0.72 (d, 3H) ).

단계 3- 9-(2-사이클로펜타-2,4-다이에닐리덴-1-메틸-에틸)-9 H -플루오렌의 합성

Step 3- Synthesis of 9-(2-cyclopenta-2,4-dienylidene-1-methyl-ethyl)-9H - fluorene

o Course:

To a stirred solution of 2-(9 H -fluoren-9-yl)-propionaldehyde (1.6 g, 7.20 mmol) in MeOH (60 mL) was added cyclopentadiene (1.42 g, 21.62 mmol) at 0-5° C. added from; Stir at this temperature for 5 minutes. Then pyrrolidine (0.19 g, 1.44 mmol) is added as crystals to the reaction mixture at 0-5°C. The reaction mixture is allowed to warm to room temperature and stirred for another 16 h.

The excess pyrrolidine is then quenched with acetic acid. Methanol is evaporated and the residue is dissolved in EtOAc (70 ml) and washed with water (2x50 ml) and brine solution (2x50 ml). The organic portion is dried over sodium sulfate and it is evaporated. The resulting crude product was purified by column chromatography (hexane) to give the desired product 9-(2-cyclopenta-2,4-dienylidene-1-methyl-ethyl) -9H -fluorene as a yellow color. It is obtained in 89% yield as a sticky liquid.

o Results:

The accompanying Figure 3 confirms the formation of compound 9-(2-cyclopenta-2,4-dienylidene-1-methyl-ethyl)-9 H -fluorene; ¹ H NMR (CDCl ₃ ) shows the study results: 7.75 (t,2H), 7.60 (d,1H), 7.55 (d,1H), 7.40-7.30 (m,3H),7.26 (d,1H), 6.57 (d,2H), 6.44 (d,1H), 6.37 (d,1H), 6.15 (d, 1H), 4.16 (s, 1H), 3.77-3.72 (m, 1H), 0.92 (d, 3H).

단계 4- 9-(2-사이클로펜타-1,3-다이에닐-1-메틸-에틸)-9 H -플루오렌 (에틸 가교된 CP 리간드)의 합성

Step 4- Synthesis of 9-(2-cyclopenta-1,3-dienyl-1-methyl-ethyl)-9 H -fluorene (ethyl cross-linked CP ligand)

o Course:

To a stirred solution of 9-(2-cyclopenta-2,4-dienylidene-1-methyl-ethyl)-9 H -fluorene (1.4 g, 0.005 mmol) in ether (60 mL), LAH (10.3 ml) at 0° C. and the reaction mixture is stirred at 0° C. for 1 h. Excess LAH is quenched with sodium sulfate decahydrate. Then excess ether (100 ml) is added to the reaction mixture and it is washed with water (50 ml) and brine (50 ml). The organic portion is then dried over sodium sulfate and it is concentrated. The resulting crude product was purified by column chromatography (hexane) to give the desired product 9-(2-cyclopenta-1,3-dienyl-1-methyl-ethyl) -9H -fluorene in 83% yield. to get

o Results:

The accompanying Figure 4 is ¹ HNMR (CDCl) confirming the formation of a C2 bridged Cp ligand, 9-(2-cyclopenta-1,3-dienyl-1-methyl-ethyl)-9H-fluorene. ₃ ) shows the study results: 7.75 (t,2H), 7.59 (t,1H), 7.54 (d,1H), 7.35-7.27 (m,4H), 6.48-6.42 (m,2H), 6.27-6.23 ( m,1H), 6.08 (s,1H), 4.01 (s,1H), 2.95 (d,2H), 2.66-2.64 (m,1H), 2.52-2.47 (m,1H), 2.38-2.3 (m, 1H), 0.64 (d, 3H).

단계 5- 다이클로로-[9-(2-사이클로펜타-1,3-다이엔-1-일-1-메틸-에틸)플루오렌-9-일]-메틸-지르코늄 (안사 메탈로센 촉매)의 합성

Step 5- Dichloro-[9-(2-cyclopenta-1,3-dien-1-yl-1-methyl-ethyl)fluoren-9-yl]-methyl-zirconium (ansa metallocene catalyst) synthesis of

o Course:

Compound 9-(2-cyclopenta-1,3-dienyl-1-methyl-ethyl)-9H-fluorene (250 mg, 0.919 mmol) in a mixture of toluene (17.5 ml) and dioxane (3 ml) To the stirred solution, n-BuLi (0.77 ml, 2.1 equiv) is added dropwise at -78°C under N ₂ atmosphere. The reaction mixture is allowed to warm to room temperature over 2 hours. It is then cooled to -78° C. and solid ZrCl ₄ .2THF (346.5 mg) is added to form an orange suspension, which is allowed to warm to room temperature and stirred overnight. The color of the reaction mixture changes to light yellow. Pass the mixture through Celite. The remaining solid fractions are washed with toluene until the organic phase remains colorless. The filtrate was concentrated under reduced pressure; A light yellow viscous solid is formed. The sticky solid was washed with hexanes (2x15 ml), the hexane layer was removed with a syringe, and the solid portion was dried under reduced pressure to achieve the desired ansa metallocene catalyst, i.e. dichloro-[9-(2-cyclopenta-1,3). -Dien-1-yl-1-methyl-ethyl)fluoren-9-yl]-methyl zirconium is obtained as a light yellow solid in 72% yield.

o Results:

The accompanying Figure 5 shows the desired ansa metallocene catalyst, namely dichloro-[9-(2-cyclopenta-1,3-dien-1-yl-1-methyl-ethyl)fluoren-9-yl]- ¹ HNMR (CDCl ₃ ) studies confirming the formation of methyl zirconium show: 7.74 (t, 2H), 7.59 (d,1H), 7.45 (d,1H), 7.37-7.27 (m,5H), 6.22-6.18 (d,3H), 3.97 (s,1H), 2.91-2.86 (m,1H), 2.72-2.66 (m,1H), 0.59 (t,3H).

Example 2: Polymerization of Ethylene

Example 2 is the ansa metallocene catalyst of Example 1, that is, dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl] -Methyl-zirconium is exemplified for a process utilizing ethylene polymerization.

과정:

process:

A dry 600 mL stainless steel parr reactor equipped with a mechanical stirrer, thermometer probe is backfilled with nitrogen for 30 min. Dried hexane is introduced into the reaction flask, then 1 mL of MAO is added, and nitrogen is bubbled through the solvent under stirring at 400 rpm for 10 minutes. The nitrogen is then replaced with ethylene gas, which remains bubbled through the solvent and discharged through the vent. After 10 minutes, 6 mg of the ansa metallocene catalyst of Example 1, i.e. dichloro-[9-[1-(cyclopenta-1,3-diene-1 ) in toluene and the desired amount of MAO (5 mL) -ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium was placed in the reaction flask; Thereafter, it is placed at a temperature of 70°C. When the required temperature is reached, a constant pressure of 5 bar is applied. The polymerization reaction is thereby proceeded for 15 minutes and then quenched with 10 mL of methanol. The reactor is evacuated and the polymer is collected and precipitated in acidified methanol (1% HCl). The polymer is washed with methanol and water and dried overnight in a vacuum oven at 60° C. to obtain 2.3 gm of polymer.

Example 3: Copolymerization of ethylene/1-hexene:

Example 3 is the ansa metallocene catalyst of Example 1, that is, dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl The process of utilizing ]-methyl-zirconium for copolymerization of ethylene/1-hexene is exemplified.

과정:

process:

A dry 600 mL stainless steel wave reactor equipped with a mechanical stirrer, thermometer probe is backfilled with nitrogen for 30 min. Dried hexane is introduced into the reaction flask, then 1 ml of MAO is added, and nitrogen is bubbled through the solvent under stirring at 400 rpm for 10 minutes. The nitrogen is then replaced with ethylene gas, which remains bubbled through the solvent and discharged through the vent. After 10 minutes, 2 mg of the ansa metallocene catalyst of Example 1 in toluene and the desired amount of MAO (2.3 ml), i.e. dichloro-[9-[1-(cyclopenta-1,3-diene-1) -ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium was placed in the reaction flask; Thereafter, it is placed at a temperature of 70°C. When the required temperature is reached, 2.5 ml of 1-hexene and continuously ethylene are fed while the pressure is adjusted to a constant ethylene pressure of 5 bar. The polymerization reaction was allowed to proceed for 15 minutes and then quenched with 10 mL of methanol. The reactor is evacuated and the polymer is collected and precipitated in acidified methanol (5% HCl). The polymer is washed with methanol and water and dried in a vacuum oven at 60° C. to obtain 1.2 gm of polymer.

Example 4: Preparation of dichloro-[9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium ansa metallocene catalyst

Example 4 is a dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium ansa metallocene catalyst for preparing The process is illustrated.

실험 부분:

Experimental part:

In the present invention, all syntheses are performed under argon using standard Schlenk techniques. Hydrocarbons and ethereal solvents are purified by standard methods. Deuterated solvents C ₆ D ₆ (Cambridge Isotopes, 99.5%) and CDCl3 (Aldrich, 99.8%) are dried over activated 4A molecular sieves.

Starting materials are, for example, ZrCl ₄ (Aldrich), n BuLi (Aldrich, 1.6 M in hexanes), methylaluminoxane (MAO) (Aldrich), and ¹ H-NMR analysis is performed on a Bruker 400 MHz instrument at 25° C. All operations are performed in a dry nitrogen atmosphere, using conventional techniques necessary for handling air-sensitive compounds.

단계 1- 2-(9 H -플루오렌-9-일)-부티르산 에틸 에스테르의 제조 :

Step 1- Preparation of 2-( 9H- fluoren -9-yl)-butyric acid ethyl ester :

o Course:

To a stirred solution of compound 9 H -fluorene (10 gm, 1 equiv) in dry THF (150 ml), butyl lithium (47.5 ml, 1.5 equiv) is added dropwise at -78°C. The reaction mixture is then allowed to warm to room temperature and stirred for 3 h. Then ethyl 2-bromobutanoate (11.22 ml, 1 equiv) is dissolved in THF, added slowly to the reaction mixture at -30°C and stirred at 25°C for 1 hour. The reaction mixture is concentrated under reduced pressure. The reaction mixture is diluted with ethyl acetate and washed with water and brine. The organic layer is separated, dried over Na ₂ SO ₄ and concentrated under reduced pressure to give the crude material. The crude material is then purified by flash column chromatography to give the desired yellow liquid compound 2-(9H- fluoren -9-yl)-butyric acid ethyl ester in 71% yield.

o Results:

The accompanying FIG. 6 shows the results of a ¹ H NMR (CDCl ₃ ) study, confirming the formation of compound 2-(9 H -fluoren-9-yl)-butyric acid ethyl ester: 7.74 (d, 2H), 7.52 -7.49 (t, 2H), 7.37-7.24 (m, 4H) 4.32 (s, 1H), 4.22 (t, 2H), 3.01 (m, 1H), 1.55 (m, 1H), 1.23 (t, 3H) , 0.99 (m, 1H), 0.75 (t, 3H).

단계 2- 2-(9 H -플루오렌-9-일)-부티르알데하이드의 합성 :

Step 2- Synthesis of 2-( 9H-fluoren-9-yl) -butyraldehyde :

o Course:

To a stirred solution of 2-(9 H -fluoren-9-yl)-butyric acid ethyl ester (10.5 g, 93 mmol) in DCM (300 mL), diisobutylaluminum hydride (DIBAL-H) (49.2 ml, 25% in toluene) is added at -78°C. It is stirred at -78°C for 1 hour. After quenching the reaction with MeOH (30 ml); Extract with DCM (250 ml). The organic layer is washed with water (2x100 ml) and brine solution (2x100 ml). The organic layer is dried over sodium sulfate and evaporated to give the crude. Then, the crude product is purified by column chromatography (hexane) to obtain pure 2-(9H- fluoren -9-yl)-butyraldehyde as a white solid in 86% yield.

o Results:

The accompanying Figure 7 shows the results of a ¹ H NMR (CDCl ₃ ) study, confirming the formation of compound 2-(9 H -fluoren-9-yl)-butyraldehyde: 9.73 (s, 1H), 7.76 (d, 2H), 7.52 (d, 1H), 7.38 (t, 3H), 7.33-7.24 (m, 2H), 4.46 (s, 1H), 3.01 (m, 1H), 1.66-1.55 (m, 1H) ), 1.13-1.01 (m, 1H), 0.77 (t, 3H).

단계 3- 9-(1-사이클로펜타-2,4-다이에닐리덴메틸-프로필)-9 H -플루오렌의 합성

Step 3- Synthesis of 9-(1-cyclopenta-2,4-dienylidenemethyl-propyl)-9 H -fluorene

o Course:

To a stirred solution of compound 2-(9 H -fluoren-9-yl)-butyraldehyde (1.5 g, 6.356 mmol) in MeOH (25 mL), cyclopentadiene (1.6 ml, 19.06 mmol) was added at 0° C. was added and stirred at this temperature for 5 min. Then pyrrolidine (0.90 ml, 12.7 mmol) is added to the reaction mixture at 0°C. The reaction mixture is allowed to warm to 25[deg.] C. and then stirred for another 2 h, and the excess pyrrolidine is quenched with acetic acid. Methanol is concentrated, diluted with ethyl acetate (70 ml) and washed with water (2x50 ml) and brine (2x50 ml). The organic layer is separated, dried over sodium sulfate and concentrated under reduced pressure to give the crude material. The resulting crude material was purified by flash column chromatography (hexanes) to give the desired fulvene intermediate 9-(1-cyclopenta-2,4-dienylidenemethyl-propyl) -9H -fluorene to light yellow Obtained as a liquid in 86% yield.

o Results:

The accompanying Figure 8 shows the results of a ¹ H NMR (CDCl ₃ ) study, confirming the formation of the fulvene intermediate 9-(1-cyclopenta-2,4-dienylidenemethyl-propyl)-9 H -fluorene. Shows: 7.75 (q, 2H), 7.61 (d, 1H), 7.55 (d, 1H), 7.40 (t,1H), 7.32 (t,1H), 7.24 (t, 1H), 6.53 (d,2H) , 6.41 (d,1H), 6.21 (d,1H), 6.10 (d, 1H), 4.19 (s, 1H), 3.49-3.42 (m, 1H), 1.44-1.25 (m, 2H), 0.82 (t) , 3H).

단계 4- 원하는 Cp 리간드 9-(1-사이클로펜타-2,4-다이에닐메틸-프로필)-9 H -플루오렌의 합성:

Step 4- Synthesis of desired Cp ligand 9-(1-cyclopenta-2,4-dienylmethyl-propyl)-9 H -fluorene:

o Course:

To a stirred solution of compound 9-(1-cyclopenta-2,4-dienylidenemethyl-propyl)-9H-fluorene (1.3 g, 4.557 mmol) in ether (20 mL), LAH (6.8 ml, 1.5 equivalent) at 0° C. and stirred at 0° C. for 1 hour. After total consumption of starting material (monitored by TLC), excess LAH is quenched using a purge operation and the reaction mixture is diluted. The organic layer is washed with water and brine. The organic layer is separated, dried over sodium sulfate and concentrated under reduced pressure to give the crude material. The crude material was purified by flash column chromatography to give the desired Cp ligand 9-(1-cyclopenta-2,4-dienylmethyl-propyl)-9 H -fluorene as a light yellow oil in 84% yield (1 g, 76.2%).

o Results:

The accompanying FIG. 9 shows the results of a ¹ H NMR (CDCl ₃ ) study confirming the formation of the desired Cp ligand 9-(1-cyclopenta-2,4-dienylmethyl-propyl)-9H-fluorene. : 7.75 (d,2H), 7.58 (t,1H), 7.50 (d,1H), 7.37-7.24 (m,4H), 6.42-6.22 (m,2H), 6.18-6.02 (s,1H), 4.1 (s, 1H), 2.98 (s, 1H), 2.85 (s, 1H), 2.42-2.37 (m, 1H), 2.28-2.17 (m,2H), 1.3-1.14 (m,2H), 0.89 (t , 3H).

단계 5- 안사 메탈로센 촉매 다이클로로 -[9-[1-(사이클로펜타-1,3-다이엔-1-일메틸)프로필]플루오렌-9-일]-메틸-지르코늄 의 합성:

Step 5- Synthesis of ansa metallocene catalyst dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium :

o Course:

A stirred solution of compound 9-(1-cyclopenta-2,4-dienylmethyl-propyl)-9H-fluorene (300 mg, 1 eq) in a mixture of toluene (21 ml) and dioxane (1.8 ml) Then, -BuLi (1.2 ml, 2.2 equiv) is added dropwise at -78°C under N ₂ atmosphere. The reaction mixture is allowed to warm to room temperature over 2 hours. It is then cooled to -78°C and solid ZrCl ₄ .2THF (415.8 mg, 1 eq) is added to form an orange suspension, which is allowed to warm to room temperature and stirred at room temperature for 4 hours. The color of the reaction mixture changes to light yellow. Pass the mixture through Celite. The remaining solid fractions are washed with toluene until the organic phase remains colorless. The filtrate was concentrated under reduced pressure; A light yellow viscous solid is formed. The sticky solid is washed with hexanes (2x15 ml), the hexane layer is removed with a syringe, and the solid portion is dried under reduced pressure to achieve the desired ansa metallocene catalyst, i.e. dichloro- [9-[1-(cyclopenta-1, 3-Dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium is obtained as a light brown solid in 83% yield.

o Results:

The accompanying Figure 10 shows the desired ansa metallocene catalyst, i.e. dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl]-methyl- ¹ H NMR (CDCl ₃ ) studies confirming the formation of zirconium show the results: 7.72-7.24 (m,8H), 6.05 (d,1H), 5.86 (s,1H), 3.96 (s,1H), 2.55 (m,1H), 2.44-2.24 (m,2H), 1.61-1.51 (m,2H), 0.82 (t,3H).

Example 5: Polymerization of Ethylene

Example 5 is the ansa metallocene catalyst of Example 4, that is, dichloro- [9-[1-(cyclopenta-1,3-dien-1-ylmethyl)propyl]fluoren-9-yl] -Methyl-zirconium is exemplified for a process utilizing ethylene polymerization.

과정:

process:

A dry 600 ml stainless steel wave reactor equipped with a mechanical stirrer, thermometer probe is backfilled with nitrogen for 30 minutes. Dried hexane is introduced into the reaction flask, then 1 ml of MAO is added, and nitrogen is bubbled through the solvent under stirring at 400 rpm for 10 minutes. The nitrogen is then replaced with ethylene gas, which remains bubbled through the solvent and discharged through the vent. After 10 minutes, 2.5 mg of the ansa metallocene catalyst of Example 4, i.e. dichloro-[9-[1-(cyclopenta-1,3-diene-1 ) in toluene and the desired amount of MAO (3.7 ml) -ylmethyl)propyl]fluoren-9-yl]-methyl-zirconium was placed in the reaction flask; Thereafter, it is placed at a temperature of 70°C. When the required temperature is reached, a constant ethylene pressure of 5 bar is applied. The polymerization reaction was allowed to proceed for 10 minutes and then quenched with 10 mL of methanol. The reactor is evacuated and the polymer is collected and precipitated in acidified methanol (5% HCl). The polymer is washed with methanol and water and dried in a vacuum oven at 60° C. to obtain 1.2 gm of polymer.

Example 6: Comparative data of the present invention in terms of the nearest prior art

Example 6 provides a comparative agent of the present invention in terms of the nearest prior art.

The most important features and results obtained by the present invention were compared with those reported in the nearest prior art (I) as shown in Table 1 below:

I. US6100416A (hereinafter referred to as 'prior art I') cites a process for preparing ethylene-crosslinked metallocenes comprising the following steps:

a) reacting fluorenyllithium with 1,2-dibromoethane to produce 1-(9-fluorenyl)-2-bromoethane;

b) 1-(9-fluorenyl)-2-[1-(2) by reacting 1-(9-fluorenyl)-2-bromoethane with 2,4,7-trimethylindenyllithium producing a ,4,7-trimethyl)indenyl]ethane precursor;

c) reacting the 1-(9-fluorenyl)-2-[1-(2,4,7-trimethyl)indenyl]ethane precursor with butyllithium to form a dilithium salt thereof; and

d) reacting said dilithium salt with a transition metal halide selected from halides of titanium, zirconium and hafnium to produce a metallocene.

comparative data closest prior art for comparison
specific features/results described in the nearest prior art obtained in the present invention
I - Yield (%) for ethylene (C2) crosslinked ansa metallocene precursor - as low as 14-29% - 70 to 90%. - Generation of impurities such as spiro-cyclopropane - Yes
Formed as reported - not formed

Therefore, from the comparative data in Table 1 above, Prior Art I reports the formation of Cp ligands in very poor yields, i.e., 14-29%, mainly due to the formation of impurities such as spiro-cyclopropane. Additionally, it has been observed that such poor yields of Cp ligands of the prior art are not sufficiently suitable to carry out metal complex reactions. In contrast, the process currently developed from the data in Table 1 can advantageously reduce the formation of unwanted impurities, resulting in superior yields of the final product, i.e. ethylene (C2) crosslinked ansa metallocene precursor / Cp ligand; That is, it results in formation in a yield of 70-90%. Therefore, these Cp ligands can be readily used in further complex reactions to form ethylene crosslinked ansa metallocene catalysts in good yields (70-85%).

Claims (12)

A new and improved process for synthesizing C2 (ethylene) bridged cyclopentadienyl ligands having the general formula (I):

wherein R1 to R8 are the same or different and at each occurrence H, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C10 alkenyl, substituted or unsubstituted C1-C10 alkynyl , substituted or unsubstituted C1-C12 heterocyclyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1-C12 aromatic ring system, silyl, alkylsilyl; any two consecutive groups from R1 to R8 may together form a substituted or unsubstituted aromatic, partially saturated or saturated fused ring system with or without a heteroatom selected from N, O, S;
The process is:
a. reacting the halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;
b. reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;
c. Another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt is added to the aldehyde intermediate of step (b) in the presence of a saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst. adding to form a fulvene derivative; next
d. reducing the fulvene derivative with a reducing agent to form a C2 (ethylene) bridged cyclopentadienyl ligand;
includes,
wherein the process essentially avoids the formation of any unwanted spiro-cyclopropane impurities. A novel and improved process for synthesizing C2 (ethylene) crosslinked ansa metallocene catalysts, comprising:
a. reacting the halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;
b. reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;
c. Another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt is reacted with the aldehyde of step (b) in the presence of an essentially saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst. adding to the intermediate to form the fulvene intermediate;
d. reducing the fulvene derivative with a reducing agent to form a C2 (ethylene) bridged cyclopentadienyl ligand; next
e. lithiating the C2 (ethylene) bridged cyclopentadienyl ligand with a lithiating agent; and
f. reacting the lithiated ligand with MCl4 to form an ansa metallocene catalyst, wherein M is a transition metal preferably selected from Ti, Hf and Zr, preferably Zr;
A process comprising An improved process for synthesizing C2 crosslinked ansa metallocene catalysts comprising:
a. reacting the halo-ester compound with a substituted or unsubstituted cyclopentadienyl ( Cp ¹ ) metal salt to form an ester intermediate;
b. reducing the ester intermediate with a reducing agent to form an aldehyde intermediate;
c. Another substituted or unsubstituted cyclopentadienyl ( Cp ² ) metal salt is reacted with the aldehyde intermediate of step (b) in the presence of a saturated cyclic secondary amine, preferably a saturated secondary N-heterocyclic catalyst. to form a fulvene intermediate; next
d. adding a lithiating agent and MCl ₄ directly to the fulvene intermediate to form an ansa metallocene catalyst, wherein M is a transition metal preferably selected from Ti, Hf and Zr, preferably Zr;
A process comprising 4. Process according to claim 1 or 2 or 3, characterized in that the halo-ester is selected from bromo-esters or chloro-esters. 4. Process according to claim 1 or 2 or 3, characterized in that Cp ¹ or Cp ² is selected from cyclopentadienyl, fluorenyl, indenyl. 4. Process according to claim 1 or 2 or 3, characterized in that the metal salt of Cp ¹ or Cp ² is selected from butyl lithium (BuLi) or potassium tert-butoxide. 4. Process according to claim 1 or 2 or 3, characterized in that the reducing agent is selected from the group consisting of diisobutylaluminum hydride (DIBALH), lithium aluminum hydride (LAH). 4. Process according to claim 1 or 2 or 3, characterized in that the saturated cyclic secondary amine crystals are selected from the group consisting of pyrrolidine, piperidine and morpholine. Process according to claim 2 or 3, characterized in that the lithiating agent is selected from n-butyl lithium (nBuLi), lithium triethylborohydride (LiEt3BH). The process according to claim 1, characterized in that it produces a C2 (ethylene) bridged cyclopentadienyl ligand having a yield of 70-90%. The process according to claim 2 or 3, characterized in that it produces an ansa metallocene catalyst having a yield of 70-85%. An ansa metallocene catalyst prepared by the process as claimed in any one of claims 1 to 11, having the structure II:

in the formula,
R1 to R8 are the same or different and at each occurrence are H, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C1-C10 alkenyl, substituted or unsubstituted C1-C10 alkynyl, substituted independently selected from substituted or unsubstituted C1-C12 heterocyclyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1-C12 aromatic ring systems, silyl, alkylsilyl; any two consecutive groups from R1 to R8 may together form a substituted or unsubstituted aromatic, partially saturated or saturated fused ring system with or without a heteroatom selected from N, O, S;
M represents one of groups 3 to 12 of the Periodic Table of the Elements, preferably a transition metal selected from Ti, Zr and Hf;
X is independently selected from the group consisting of a hydrocarbyl radical having 1 to 20 carbon atoms, hydride, amide, alkoxide, sulfide, phosphide, halide, diene, amine, phosphine, ether, and combinations thereof and two X's include those that may form part of an aromatic or non-aromatic fused ring or ring system;
R9 and R10 are the same or different and at each occurrence are H, Si, alkylsilyl, substituted or unsubstituted C1-Cl2 alkyl, substituted or unsubstituted C1-C12 cycloalkyl, substituted or unsubstituted C1- independently selected from C10 alkenyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl.

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