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Title:
SYNTHESIS OF AN AMINE-CONTAINING CYCLOPENTADIENE
Document Type and Number:
WIPO Patent Application WO/1997/042157
Kind Code:
A1
Abstract:
Process for the substitution of a cyclopentadiene with at least one amine-containing substituent by deprotonating a cyclopentadiene compound by reaction with a base, sodium or potassium and then reacting the resulting cyclopendadienyl anion with a compound containing an amine group, wherein the compound containing the amine group is a compound according to the formula (R'2N-R-Sul), in which R is a bonding group, R' is a substituent, N is a nitrogen atom and Sul is a sulphonyl group, which compound has been formed in situ by a reaction of an amino alcohol compound with successively a base and a sulphonyl halide.

Inventors:
Ijpeij
Edwin
Gerard, Van Beek
Johannes
Antonius
Maria, Gruter
Gerardus
Johannes
Maria
Application Number:
PCT/NL1997/000194
Publication Date:
November 13, 1997
Filing Date:
April 16, 1997
Export Citation:
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Assignee:
Dsm N.
Ijpeij, Edwin Gerard Van Beek Johannes Antonius Maria Gruter Gerardus Johannes Maria
International Classes:
C07C209/68; C07C211/25; C07F17/00; C07F19/00; C08F4/64; C08F10/00; (IPC1-7): C07C211/25; C07C209/68; C07F17/00; C08F10/00
Domestic Patent References:
WO1995000562A1
Foreign References:
DE4303647A1
Other References:
SYNTHESIS (1993), (7), 684-6 CODEN: SYNTBF;ISSN: 0039-7881, 1993, XP000601948 JUTZI, PETER ET AL: "Dimethylaminoalkyl and methoxyalkyl substituted tetramethylcyclopentadienes: synthesis of novel polydentate ligands" cited in the application
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Claims:
C L A I M S
1. Process for the substitution of a cyclopentadiene with at least one aminecontaining substituent by deprotonating a cyclopentadiene compound by reaction with a base, sodium or potassium and then reacting the resulting cyclopentadienyl anion with a compound containing an amine group, characterized in that the compound containing the amine group is a compound according to the formula (R f2NRSul) , in which R is a bonding group, R' is a substituent, N is a nitrogen atom and Sul is a sulphonyl group, which compound has been formed in situ by reaction of an amino alcohol compound with successively a base and a sulphonyl halide.
2. Process according to Claim 1, characterized in that the starting compound used is a cyclopentadiene compound which is already substituted with at least one other group.
3. Process according to any one of claims 12, in which the process is carried out under the influence of a Lewis base whose conjugated acid has a dissociation constant, pKa, of 2.5 or less.
4. Process according to any one of claims 13, in which R has the structure (ER22)p where p = 14 and E is an atom from group 14 of the Periodic System.
5. Process according to Claim 2, characterized in that the product from the process described in Claim 2 is converted into a salt by reaction with potassium, sodium or a base, after which this salt is washed with a dispersing agent in which the salt of the nongeminal products does hardly dissolve.
6. Cyclopentadiene containing at least 1 amine containing substituent having the form RDR'2 and at least 1 other substituent.
7. Use of a substituted cyclopentadiene according to Claim 6 as ligand in a metal complex.
8. Use of a metal complex according to Claim 7, for the polymerization of an olefin.
Description:
SYNTHESIS OF AN AMINE-CONTAINING CYCLOPENTADIENE

The invention relates to a process for the substitution of a cyclopentadiene (Cp) with at least one amine-containing substituent by deprotonating a Cp compound by reaction with a base, sodium or potassium and then reacting the resulting cyclopentadienyl anion with a compound containing an amine group.

A process for such a synthesis is known from Rees et al. (OPPI Briefs, vol. 24, No. 5, 1992). In that publication it is described that an amine- containing substituent can be obtained by substitution with an amine-containing alkyl chloride. A drawback of these chlorides is that they are highly toxic. Another drawback is that these chlorides are only commercially available in the form of the HCl salt and the HCl has to be removed in an additional reaction step.

The object of the invention is to provide a process for the synthesis of a cyclopentadiene with an amine-containing substituent in which the use of the amine-containing alkyl chloride is avoided and which gives a high yield.

The invention is characterized in that the compound containing the amine group is a compound according to the formula (R ' 2 N-R-Sul ) , in which R is a bonding group, R' is a substituent, N is a nitrogen atom and Sul is a sulphonyl group, which compound has been formed in situ by reaction of an amino alcohol compound with successively a base and a sulphonyl halide.

Surprisingly it has been found now that if the synthesis is carried out as described above, the yield of the cyclopentadiene with at least one amine- containing substituent is high. A further advantage of the process according to the invention is that amino alcohol compounds and sulphonyl halides are low-priced starting compounds. C. Qian et al. (Inorg. Chem., 1994, 33, 3382-3388) do describe a process for the synthesis of a cyclopentadiene with an ether-containing substituent by reacting the cyclopentadienyl anion with a tosylate of the ether, but this process in not suitable for the introduction of an amine-containing substituent onto the cyclopentadiene, because tosylates of amines are unstable under the described circumstances.

The above process can also be applied if the starting compound is a Cp compound which is already substituted with at least one other group.

When a substituted CP-compound is used as a starting compound, the following state of the art is also of importance.

Szymoniak et al. (J. Org. Chem., 1990, 55, 1429-1432) describe a process for the synthesis of a tetramethyl cyclopentadiene with a diphenylphosphine- containing substituent. The synthesis takes place as follows: The tetramethyl cyclopentadienyl is deprotonated to the anion, which is reacted with 2- chloroethyl tosylate and next with lithiumdiphenyl phosphide. The yield is 68%. The 1 H-NiyiR-spectrum of the obtained compound is characteristic for 1,2,3,4,5- substituted (diphenylphosphinoethyl)tetramethyl- cyclopentadiene.

However, Jutzi et al. (Synthesis 1993, 684) describe that such a synthesis route cannot yield (diphenylphosphinoethyl)tetramethylcyclopentadiene because geminal substitution by the 2-chloroethyl tosylate mainly occurs. Jutzi obtains these geminal

products with a yield of 65%.

Geminally substituted cyclopentadiene is a cyclopentadiene containing two substituents, which are not identical to a hydrogen atom, on the sp 3 carbon atom of the cyclopentadiene ring.

Surprisingly it has been found now that if a substituted Cp compound is applied as starting compound for the synthesis according to the invention, only part of the product formed is geminal. These geminal products can simply be isolated by converting the product from the above synthesis into a salt by reaction with potassium, sodium or a base, after which this salt is washed with a dispersing agent in which the salt of the non-geminal products hardly dissolves. Another advantage of the synthetic method according to the invention is that only one synthetic step is required to apply one or more substituents of the form -RNR' 2 to a substituted Cp-compound, while according to the process applied by Szymoniak and Jutzi more synthetic steps are required.

By Cp compounds are understood Cp as such and substituted Cp, with the possibility of two substituents forming a closed ring.

A substituted Cp compound contains at least 1 alkyl, alkenyl and/or aralkyl substituent.

The alkyl substituents may be linear as well as branched and cyclic alkyl groups. Further, these may also contain, besides carbon and hydrogen, one or more hetero atoms from groups 14-17 of the Periodic System, for instance 0, N, Si or F. Examples of suitable substituting groups are methyl, ethyl, (iso)propyl, secondary butyl, pentyl, hexyl and octyl, (tertiary) butyl and higher homologues, cyclohexyl, benzyl. Combinations of these substituents on the Cp compound are also possible. For the Periodic System see the new IUPAC notation to be found on the inside of the cover of the Handbook of Chemistry and Physics, 70th edition,

1989/1990.

Substituted Cp compounds can, for instance, be prepared by reacting a halide of the substituting compound in a mixture of Cp compound and an aqueous solution of a base in the presence of a phase transfer catalyst. A virtually equivalent quantity of the halogenated substituting compound can be used. An equivalent quantity is understood as a quantity in moles which corresponds to the desired substitution multiplicity, for example 2 mol per mole of Cp compound if disubstitution with the substituent in question is intended.

Depending on the size and the associated steric hindrance of the compounds to be substituted it is possible to obtain trisubstituted to hexasubstituted Cp compounds. If a reaction with tertiary halides is carried out, as a rule only trisubstituted Cp compounds can be obtained, whereas with primary and secondary halides it is generally possible to achieve tetra and often even penta- or hexasubstitution. Because the process according to the invention comprises introduction of an additional amine-containing substituent in a second step, at most four substituents are introduced in this first step. The substituents are preferably used in the process in the form of their halides.

By means of the present process it is also possible, without intermediate isolation or purification, to obtain Cp compounds which are substituted by specific combinations of substituents. It is thus possible for instance first to effect a two fold substitution by means of a certain substituting compound, whereafter in the same reaction mixture a third substitution can occur by adding a second, other substituting compound to the mixture after some time. This can be repeated, so that it is also possible to prepare Cp derivatives having three or more different

substituents.

The substitution takes place in a mixture of the Cp compound and an aqueous solution of a base. The concentration of the base in the solution is in the range between 20 and 80 wt.%. Hydroxides of an alkali metal, for example K or Na are highly suitable as a base. The base is present in an amount of 5-60 mol per mole of Cp compound.

The substitution takes place in the presence of a phase transfer catalyst which is able to transfer OH ions from the aqueous phase to the organic phase, the OH ions reacting in the organic phase with a H atom which can be split off from the Cp compound. The organic phase contains the Cp-compound and the substituting compound. The phase transfer catalysts are used in an amount of 0.01 - 2 equivalents on the basis of the amount of Cp-compound.

In the implementation of the process the components can be added to the reactor in various sequences.

After the reaction is complete, the aqueous phase and the organic phase which contains the Cp compound are separated. The Cp compound is then obtained from the organic phase by fractional distillation.

In the first step of the synthesis route the Cp compound is deprotonated by reaction with a base, sodium or potassium.

As base can be applied for instance organolithium compounds (R 3 Li) or organomagnesium compounds (R 3 MgX), where R 3 is an alkyl, aryl, or aralkyl group and X is a halide, such as for instance n-butyl lithium or i-propylmagnesium chloride.

Potassium hydride, sodium hydride, inorganic bases, such as NaOH and KOH, and alcoholates and amides of Li, K and Na can also be used as base.

Mixtures of the above-mentioned compounds can

also be used.

This reaction can be carried out in a polar dispersing agent, such as for instance an ether. Examples of ethers are tetrahydrofuran (THF) and dibutyl ether. Nonpolar solvents, such as for instance toluene, can also be used.

Next, in a second step of the synthesis route, cyclopentadienyl anion reacts with a compound according to the formula (R' 2 N-R-Sul) , in which R is a bonding group, R' is a substituent, N is a nitrogen atom and Sul is a sulphonyl group.

In the following the respective components of the compound will be considered in more detail.

a) De -RNR' ? -σroup

The R group constitutes the shortest bond between the Cp-compound and the NR' 2 group. The length of the shortest bond between Cp and N is critical in that, if the Cp compound is used as a ligand in a metal complex, it determines the accessibility of the metal to the NR' 2 group, a factor which facilitates any intramolecular coordination. If the R group (or bridge) is too short, the nitrogen may not be able to coordinate properly owing to ring tension.

The R' groups can each separately be a hydrocarbon radical with 1-20 carbon atoms (such as alkyl, aryl, aralkyl, etc.). Examples of such hydrocarbon radicals are methyl, ethyl, propyl, butyl, hexyl, decyl, phenyl, benzyl and p-tolyl. R' can also be a substituent which, in addition to or instead of carbon and/or hydrogen, comprises one or more hetero atoms from groups 14-16 of the Periodic System of the Elements. Thus a substituent can be a group comprising N, 0 and/or Si.

The R group can be a hydrocarbon group with

1-20 carbon atoms (such as alkylidene, arylidene, arylalkylidene, etc.). Examples of such groups are methylene, ethylene, propylene, butylene, phenylene, with or without a substituted side chain. The R group preferably has the following structure:

(-ER 2 2 -) p

where p = 1-4 and E represents an atom from group 14 of the Periodic System. The R 2 groups can each be H or a group as defined for R'.

More preferably the R-group has the structure

-(R 2 -(ER 2 -)p-ι

so that the R-group is linked to the Cp-compound with a carbon atom.

Thus the main chain of the R group can also comprise silicon or germanium besides carbon. Examples of such R groups are: dialkyl silylene, dialkyl germylene, tetra-alkyl disilylene or dialkyl silaethylene (-(CH 2 ) (SiR 2 2 )-) . The alkyl groups (R 2 ) in such a group preferably have 1 to 4 carbon atoms and more preferably are a methyl or ethyl group.

The NR' 2 group consists of a nitrogen atom N and two substituents R' bonded to N. By preference the R' group is an alkyl, more preferably an n-alkyl group with 1-20 carbon atoms. More preferably the R' group is an n-alkyl group with 1-10 carbon atoms. Another possibility is that two R' groups are linked to each other in a ring-shaped structure in the NR' 2 group (which means that the NR' 2 group can be a pyrrolidinyl group). The NR' 2 group can form a coordinative bond with a metal.

b) the sulphonyl group

The structure of the sulphonyl group is represented by -OS0 2 R 6 , where R 6 is a hydrocarbon radical having 1-20 carbon atoms (such as alkyl, aryl, aralkyl and the like). Examples of such hydrocarbon radicals are butane, pentane, hexane, benzene, naphthalene. In addition to or instead of carbon and/or hydrogen, R 6 can also comprise one or more hetero atoms from groups 14-17 of the Periodic System of the Elements, such as N, O or F.

Examples of sulphonyl groups are: phenylmethane sulphonyl, benzene sulphonyl, 1-butane sulphonyl, 2,5- dichlorobenzene sulphonyl, 5-dimethylamino-l- naphthalene sulphonyl, pentafluorobenzene sulphonyl, p- toluene sulphonyl, trichloromethane sulphonyl, trifluoromethane sulphonyl, 2,4,6-triisopropylbenzene sulphonyl, 2 , 4, 6-trimethylbenzene sulphonyl, 2- mesitylene sulphonyl, methane sulphonyl, 4- methoxybenzene sulphonyl, 1-naphthalene sulphonyl, 2- naphthalene sulphonyl, ethane sulphonyl,

4-fluorobenzene sulphonyl and 1-hexadecane sulphonyl. The sulphonyl group preferably is p-toluene sulphonyl or trifluoromethane sulphonyl.

The compound according to formula (R' 2 N-R-Sul) is formed in situ by reaction of an aminoalcohol compound (R' 2 NR-OH) with successively a base (as described above), potassium or sodium and a sulphonyl halide (Sul-X).

The second reaction step can be carried out in a polar dispersing agent, such as for instance an ether. Examples of ethers are THF or dibutyl ether. Nonpolar solvents, such as for instance toluene, can also be used. The reaction is carried out at a temperature of -60 to 80°C. During the second step of the reaction Na, K or a base, such as mentioned for the deprotonation of the Cp-compound, can be used as a base.

The synthesis route according to the invention may in part result in geminal products. In geminal substitution the number of substituents increases by 1, but the number of substituted carbon atoms does not increase. The amount of geminal products formed is low if the synthesis starts from a substituted Cp compound with 1 substituent, and increases with an increasing number of substituents in the substituted Cp compound. If sterically large substituents are present on the substituted Cp compound, geminal products will hardly form, if at all. Examples of sterically large substituents are secondary or tertiary alkyl substituents.

The amount of geminal product that is formed is also low if the second step of the reaction is carried out under the influence of a Lewis base whose conjugated acid has a dissociation constant, pK a , of - 2.5 or less. The values of pK a are based on D. D. Perrin: Dissociation Constants of Organic Bases in Aqueous Solution, International Union of Pure and Applied Chemistry, Butterworths, London 1965. The values have been determined in aqueous H 2 S0 4 solution.

Non-cyclic ethers can be mentioned as an example of suitable Lewis bases. If geminal products have formed in the process according to the invention, these can easily be separated from the non-geminal products by converting the mixture of geminal and non-geminal products into a salt by reaction with potassium, sodium or a base, after which said salt is washed with a dispersant in which the salt of the nongeminal products dissolves poorly or not at all.

The compounds as mentioned above may be used as base. Suitable dispersants are nonpolar dispersants, such as alkanes. Examples of suitable alkanes are: heptane and hexane.

The cyclopentadienes with at least one amine- containing substituent are very suitable for use as ligand in a metal complex.

The metal complexes with the Cp compounds as ligands are suitable as catalyst component. Said cata¬ lyst components are, together with a cocatalyst, used in the polymerization of olefins.

The invention will be explained further on the basis of examples, without being restricted thereto.

Examples Experimental section:

Reactions were followed in time with the aid of gas chromatography ( GC type: Hewlett Packard 5890

Series II, provided with autosampler type HP6890 Series Injector, integrator type HP3396A and HP Crosslinked Methyl Silicon Gum (25 m x 0.32 mm x 1.05 μm) column with one of the following temperature programmes: 50°C (5 min), rate: 7.5°C/min, 250°C (29 minutes) or 150°C (5 min), rate: 7.5°C/min. 250°C (29 minutes). The products were characterized using GC-MS (type Fisons MD800, equipped with a quadrupole mass detector, autoinjector Fisons AS800 and CPSilδ column (30 m x 0.25 mm x 1 μm , low bleed) using one of the following temperature programmes: 50°C (5 min), rate: 7.5°C/min, 250°C (29 minutes) or 150°C (5 min), rate: 7.5°C/min, 250°C (29 minutes) and Bruker ACP200 NMR ( X H = 200 MHz; 13 C = 50 MHz) or Bruker ARX400 NMR ^H = 400 MHz; L3 C = 100 MHz). Complexes were characterized using a Kratos MS80 mass spectrometer or a Finnigan Mat 4610 mass spectrometer.

Example I

Preparation of 2-(N,N-dimethylamino)ethyl tosylate in situ

A solution of n-butyllithium in hexane (1 equivalent) was added at -10°C (dispensing time: 60 minutes) to a solution of 2-dimethylaminoethanol (1 equivalent) in dry THF under dry nitrogen in a three- neck round-bottom flask provided with a magnetic stirrer and a dropping funnel. After all the butyllithium had been added, the mixture was brought to room temperature and stirred for 2 hours. The mixture was then cooled (-10°C), after which paratoluenesulphonyl chloride (1 equivalent) was added. The solution was then stirred for 15 minutes at this temperature before the solution was added to a cyclopentadienyl anion.

Comparable tosylates can be prepared using the above-described method. In a number of the examples below, a tosylate is always coupled to alkylated Cp compounds. During this coupling, geminal coupling also takes place in addition to the required substitution reaction. In nearly all cases it was possible to separate the geminal isomers from the nongeminal isomers by converting the nongeminal isomers into their sparingly soluble potassium salt, followed by washing of said salt with a solvent in which said salt is not soluble or is sparingly soluble.

Example II Example Ila: Preparation of tri(2- propyl)cvclopentadiene

180 g (2.25 mol) of clear 50% NaOH, 9.5 g (23 mmol) of Aliquat 336 and 15 g (0.227 mol) of freshly cracked cyclopentadiene were combined in a double-walled reactor having a capacity of 200 ml and provided with baffles, cooler, top stirrer, thermometer and dropping funnel. The reaction mixture was

vigorously stirred for several minutes at a rotary speed of 1385 rpm. Then 84 g (0.68 mol) of 2-propyl bromide were added. During this process, the mixture was cooled with water. A few minutes after adding the 2-propyl bromide, the temperature rose approximately 10°C. It was demonstrated with GC that, approximately 30 minutes after adding all the 2-propyl bromide, (monosubstituted) 2-propylcyclopentadiene was formed. The reaction mixture was then heated to 50°C. After 2 hours, stirring was stopped and phase separation was awaited. The water layer was drained off and 180 g (2.25 mol) of fresh 50% NaOH were added. Stirring was then carried out for a further hour at 50°C. It was demonstrated with GC that, at that instant, between 90 and 95% of tri (2-propyl )cyclopentadiene was present in the mixture of disubstituted, trisubstituted and tetrasubstituted cyclopentadiene. The product was distilled at 1.3 mbar and 77 - 78°C. After distillation, 31.9 g of tri (2-propyl)cyclopentadiene were obtained.

The characterization was carried out with the aid of GC, GC-MS, 13 C- and Η-NMR.

Example lib: Preparation of (dimethylaminoethyl )tri (2- propyl )cyclopentadienylpotassium

A solution of 62.5 ml (1.6 M in n-hexane; 100 mmol) of n-butyllithium was added to a solution of 19.2 g (100 mmol) of triisopropylcyclopentadiene in 250 ml of THF at -60°C in a dry 500 ml three-neck flask having a magnetic stirrer under a dry nitrogen atmosphere. After heating to room temperature (in approximately 1 hour), stirring was carried out for a further 2 hours. After cooling to -60°C, a solution of dimethylaminoethyl tosylate (105 mmol) (Example I) prepared in situ was added in 5 minutes. The reaction mixture was heated to room temperature, after which stirring was carried out overnight. After adding water,

the product was extracted with petroleum ether (40 - 60°C). The combined organic layer was dried (Na 2 S0 4 ) and evaporated down under reduced pressure. The conversion was greater than 95%. The geminal product isomers were removed by converting the nongeminal isomers into the sparingly soluble (2-dimethylaminoethyl)triisopropyl- cyclopentadienylpotassium, after which the potassium salt was washed with hexane. The overall yield of product (starting from triisopropylcyclopentadiene) was approximately 55%.

Example lie: Preparation of bis(dimethylaminoethyl)tri(2-propyl)cyclopentadiene

A solution of 62.5 ml (1.6 M in n-hexane; 100 mmol) of n-butyllithium was added to a solution of 19.2 g (100 mmol) of tri(2-propyl)cyclopentadiene in 250 ml of THF at -60°C in a dry 500 ml three-neck flask having a magnetic stirrer under a dry nitrogen atmosphere. After heating to room temperature (in approximately 1 hour), stirring was carried out for a further 2 hours. After cooling to -60°C, a solution of dimethylaminoethyl tosylate (105 mmol) (Example I) prepared in situ was added in 5 minutes. The reaction mixture was heated to room temperature, after which stirring was carried out overnight. After adding water, the product was extracted with petroleum ether (40 - 60°C). The combined organic layer was dried (Na 2 S0 4 ) and evaporated down under reduced pressure. The conversion was greater than 95%. Some of the product obtained in this way (10.1 g; 38.2 mmol) was alkylated yet again under the same conditions with dimethylaminoethyl tosylate (39.0 mmol).

The bis(2-dimethylaminoethyl)tri(2- propyl)cyclopentadiene was obtained with a yield of 35% via column chromatography.

Example III

Example Ilia: Preparation of dicyclohexylcyclopentadiene

A double-walled reactor having a capacity of 1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 600 g of clear 50% NaOH (7.5 mol), after which cooling was carried out to 8°C. Then 20 g (49 mmol) of Aliquat 336 and 33 g (0.5 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 172 g of cyclohexyl bromide (1.05 mol) were added. During this process, the mixture was cooled with water. After stirring for 2 hours at room temperature, the reaction mixture was heated to 70°C, after which stirring was carried out again for 6 hours. It was demonstrated with GC that 79% of dicyclohexylcyclopentadiene was present at that instant. The product was distilled at 0.04 mbar and 110 - 120°C. After distillation, 73.6 g of dicyclohexylcyclopentadiene were obtained.

The characterization was carried out with the aid of GC, GC-MS, 13 C- and ^-NMR.

Example Illb: Preparation of (dimethylaminoethyl )- dicyclohexylcyclopentadiene

A solution of n-butyllithium in hexane (18.7 ml; 1.6 mol/1 ; 30 mmol) was added dropwise to a cooled (0°C) solution of dicyclohexylcyclopentadiene (6.90 g; 30.0 mmol) in dry tetrahydrofuran (125 ml) in a 250 ml three-neck round-bottom flask provided with magnetic stirrer and dropping funnel under a nitrogen atmosphere. After stirring for 24 hours at room temperature, 30.0 mmol of 2-dimethylaminoethyl tosylate (Example I) prepared in situ were added. After stirring for 18 hours, the conversion was found to be 88% and water (100 ml) was carefully added dropwise to the reaction mixture, after which the tetrahydrofuran was

distilled off. The crude product was extracted with ether, after which the combined organic phase was dried (sodium sulphate) and evaporated down. The residue was purified by means of a column containing silica gel, resulting in 7.4 g of (dimethylaminoethyl)dicyclohexyl- cyclopentadiene.

Example IV

Example IVa: Preparation of a di- and tri(2- pentyl)cyclopentadiene

A double-walled reactor having a capacity of 1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 900 g (11.25 mol) of clear 50% NaOH. Then 31 g (77 mmol) of Aliquat 336 and 26.8 g (0.41 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 155 g (1.03 mol) of 2-pentyl bromide were added in one hour. During this process, the mixture was cooled with water. After stirring for 3 hours at room temperature, the reaction mixture was heated to 70°C, after which stirring was carried out again for 2 hours. Stirring was stopped and phase separation was awaited. The water layer was drained off and 900 g (11.25 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further two hours at 70°C. It was demonstrated with GC that the mixture was composed of di- and tri(2- pentyl)cyclopentadiene (approximately 1:1) at that instant. The products were distilled at respectively 2 mbar, 79-81°C and 0.5 mbar, 102°C. After distillation, 28 g of di- and 40 g of tri(2-pentyl)cyclopentadiene were obtained.

The characterization was carried out with the aid of GC , GC-MS, 13 C- and ^-NMR.

Example IVb: Preparation of (dimethylaminoethyl)di ( 2- pentyl )cyclopentadiene

A solution of n-butyllithium in hexane (24.0 ml; 1.6 mol/1 ? 38 mmol) was added dropwise to a cooled (0°C) solution of di-2-pentylcyclopentadiene (7.82 g; 38.0 mmol) in dry tetrahydrofuran (125 ml) in a 250 ml three-neck round-bottom flask provided with magnetic stirrer and dropping funnel. After stirring for 24 hours at room temperature, 2-dimethylaminoethyl tosylate (38.0 mmol) (Example I) prepared in situ was added. After stirring for 18 hours, the conversion was found to be 92% and water (100 ml) was carefully added dropwise to the reaction mixture, after which the tetrahydrofuran was distilled off. The crude product was extracted with ether, after which the combined organic phase was dried (sodium sulphate) and evaporated down. The residue was purified using a column containing silica gel, resulting in 8.2 g of (dimethylaminoethyl)di-2-pentylcyclopentadiene.

Example IVc: Preparation of (dimethylaminoethyl)tri(2- pentyl )cyclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl )tri (2-propyl )cyclopentadiene (Example lib). The conversion was 90%. The nongeminal (dimethylaminoethyl)tri(2-pentyl)cyclopentadiene was obtained distillatively in a yield of 54%. The (dimethylaminoethyl )tri(2-pentyl)cyclopentadiene was obtained after preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively with a yield of 57%.

Example IVd: Preparation of di (n-butylaminoethyl)tri (2- pentyl )cvclopentadiene The reaction was carried out in the same way as for (dimethylaminoethyl)tri (2-propyl )cyclopentadiene (Example lib), the tosylate of N,N-di-n-butylamino-

ethanol being prepared in situ. The conversion was 88%. The 2-(di-n-butylaminoethyl)di(2-pentyl)cyclopentadiene was obtained after preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively, followed by distillation under reduced pressure, with a yield of 51%.

Example V

Example Va: Preparation of di(2-propyl)cyclopentadiene 180 g of clear 50% NaOH (2.25 mol), 9.5 g

(23 mmol) of Aliquat 336 and 15 g (0.227 mol) of freshly cracked cyclopentadiene were combined in a double-walled reactor having a capacity of 200 ml and provided with baffles, cooler, top stirrer, thermometer and dropping funnel. The reaction mixture was vigorously stirred for several minutes at a speed of 1385 rpm. Then 56 g (0.46 mol) of 2-propyl bromide were added. During this process, the mixture was cooled with water. Several minutes after adding the 2-propyl bromide, the temperature rose approximately 10°C. Then stirring was carried out for 6 hours at 50°C. It was demonstrated with GC that 92% di(2- propyl)cyclopentadiene was present in the mixture of di- and tri(2-propyl)cyclopentadiene at that instant. The product was distilled at 10 mbar and 70°C. After distillation, 25.35 g of di(2-propylJcyclopentadiene were obtained. The characterization was carried out with the aid of GC, GC-MS, 13 C- and ^-NMR.

Example Vb: Preparation of (dimethylaminoethyl)di(2- propyl)cvclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl)tri(2-propyl)cyclopentadiene

(Example lib). The conversion was 97%. The (dimethyl- aminoethyl)di(2-propyl)cyclopentadiene was obtained distillatively with a yield of 54%.

Example Vc: Preparation of (di-n-butylaminoethyl)di(2- propyl)cvclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl)tri(2-propyl)cyclopentadiene (Example lib), the tosylate of N,N-di-n-butylamino- ethanol being prepared in situ. The conversion was 94%. The nongeminal di(n-butylaminoethyl)di(2- propyl)cyclopentadiene was obtained distillatively with a yield of 53%.

Example VI

Example Via: Preparation of di(2-butyl)cvclopentadiene A double-walled reactor having a capacity of 1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 600 g of clear 50% NaOH (7.5 mol), after which the contents were cooled to 10°C. Then 30 g of Aliquat 336 (74 mmol) and 48.2 g (0.73 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 200 g (1.46 mol) of 2-butyl bromide were added in half an hour. During this process, the mixture was cooled with water. After stirring for 2 hours at room temperature, the reaction mixture was heated to 60°C, after which stirring was carried out again for 4 hours. It was demonstrated with GC that more than 90% of di(2- butyl)cyclopentadiene was present in the mixture at that instant. The product was distilled at 20 mbar and 80 - 90°C. After distillation, 90.8 g of di(2- butyl)cyclopentadiene were obtained.

The characterization was carried out with the aid of GC, GC-MS, 13 C- and X H-NMR.

Exampie VIb: Preparation of (dimethylaminoethyl)di(2- butyl)cyclopentadiene

A solution of n-butyllithium in hexane (31.2 ml; 1.6 mol/1; 50 mmol) was added dropwise to a cooled

(0°C) solution of di(2-butylJcyclopentadiene (8.90 g; 50.0 mmol) in dry tetrahydrofuran (150 ml) under a nitrogen atmosphere in a 250 ml three-neck round-bottom flask provided with magnetic stirrer and dropping funnel. After stirring for 24 hours at room temperature, the 2-dimethylaminoethyl tosylate (50.0 mmol) (Example I) was added. After stirring for 18 hours, the conversion was found to be 96% and water (100 ml was carefully added dropwise to the reaction mixture, after which the tetrahydrofuran was distilled off. The crude product was extracted with ether, after which the combined organic phase was dried (sodium sulphate) and evaporated down. The residue was purified using a silica gel column, resulting in 8.5 g of (dimethylaminoethyl)di(2-butyl)cyclopentadiene.

Example VII

Example Vila: Preparation of tri(2- butyl)cyclopentadiene A double-walled reactor having a capacity of

1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 400 g (5.0 mol) of clear 50% NaOH. Then 9.6 g (24 mmol) of Aliquat 336 and 15.2 g (0.23 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 99.8 g (0.73 mol) of 2-butyl bromide were added in half an hour. During this process, the mixture was cooled with water. After stirring for half an hour at room temperature, the reaction mixture was heated to 70°C, after which stirring was carried out again for three hours. Stirring was stopped and phase separation was awaited. The water layer was drained off and 400 g (5.0 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further 2 hours at 70°C. It was demonstrated with GC that more than 90% tri(2- butyl)cyclopentadiene was present in the mixture of di-

, tri- and tetra(2-butyl)cyclopentadiene at that instant. The product was distilled at 1 mbar and 91°C. After distillation, 40.9 g of tri(2- butyl)cyclopentadiene were obtained. The characteriz- ation was carried out with the aid of GC, GC-MS, 13 C- and L H-NMR.

Example Vllb: Preparation of (dimethylaminoethyl)tri(2- butyl)cvclopentadiene The reaction was carried out in the same way as for (dimethylaminoethyl)tri(2-propyl)cyclopentadiene (Example lib). The conversion was 92%. The product was obtained distillatively with a yield of 64%.

Example VIII

Example Villa: Preparation of di- and tri(3- pentyl)cyclopentadiene

A double-walled reactor having a capacity of 1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 430 g (5.4 mol) of clear 50% NaOH. Then 23 g (57 mmol) of Aliquat 336 and 27 g (0.41 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 150 g (1.0 mol) of 3-pentyl bromide were added in one hour. During this process, the mixture was cooled with water. After stirring for 1 hour at room temperature, the reaction mixture was heated to 70°C, after which stirring was again carried out for 3 hours. Stirring was stopped and phase separation was awaited. The water layer was drained off and 540 g (6.70 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further 4 hours at 70°C. It was demonstrated with GC that the mixture was composed of di- and tri(3- pentyl)cyclopentadiene (approx. 3:2) at that instant. The products were distilled at, respectively, 0.2 mbar, 51°C and 0.2 mbar, 77 - 80°C. After distillation, 32 g

of di- and 18 g of tri(3-pentyl)cyclopentadiene were obtained.

The characterization was carried out with the aid of GC, GC-MS, 13 C- and ^-NMR.

Example Vlllb: Preparation of (dimethylaminoethyl)di (3- pentyl )cyclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl )tri (2-propyl)cyclopentadiene (Example lib). The conversion was 99%. The (dimethy¬ laminoethyl)di(3-pentyl)cyclopentadiene was obtained after preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively, with a yield of 85%.

Example VIIIc: Preparation of (di-n-butylaminoethyl )- di (3-pentyl )cyclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl)tri (2-propyl)cyclopentadiene (Example lib), the tosylate of N,N-di-n- butylaminoethanol being prepared in situ. The conversion was 95%. The product was obtained after preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively, with a yield of 75%.

Example Vllld: Preparation of (2-dimethylaminoethyl ) tri (3-pentyl)cvclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl)tri(2-propyl)cyclopentadiene (Example lib). The conversion was 94%. The (2-dimethyl¬ aminoethyl)tri (3-pentyl)cyclopentadiene was obtained after preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively, with a yield of 61%.

Exampl e IX

Example IXa: Preparation of di(2- propyl )cyclohexylcyclopentadiene

150 g of clear 50% NaOH (1.9 mol), 7 g (17.3 mmol) of Aliquat 336 and 8.5 g (0.13 mol) of freshly cracked cyclopentadiene were combined in a double-walled reactor having a capacity of 200 ml and provided with baffles, cooler, top stirrer, thermometer and dropping funnel. The reaction mixture was vigorously stirred for several minutes at a speed of 1385 rpm. Then 31.5 g (0.26 mol) of 2-propyl bromide were added. During this process, the mixture was cooled with water. The total dispensing time was 1 hour. After adding the bromide, the reaction mixture was heated to 50°C. After 2 hours, stirring was stopped and phase separation was awaited. The water layer was drained off and 150 g (1.9 mol) of fresh 50% NaOH were added. Then 20.9 g (0.13 mol) of cyclohexyl bromide were added, after which stirring was carried out for 3 hours at 70°C. It was demonstrated with GC that 80% di(2- propyl)cyclohexylcyclopentadiene was present in the mixture at that instant. The product was distilled at 0.3 mbar and 80°C. After distillation, 17.8 g of di(2- propyl)cyclohexylcyclopentadiene were obtained. The characterization was carried out with the aid of GC, GC-MS, 13 C- and ^-NMR.

Example IXb: Preparation of cyclohexyl(dimethylamino¬ ethyl)di(2-propyl)cyclopentadiene A solution of n-butyllithium in hexane (25.0 ml; 1.6 mol/1; 40.0 mmol) was added dropwise to a solution of cyclohexyldiisopropylcyclopentadiene (9.28 g; 40.0 mmol) in dry THF (150 ml) at room temperature in a Schenk vessel. Then a solution of n-butyllithium in hexane (25.0 ml; 1.6 mol/1; 40.0 mmol) was added dropwise to a cold (-78°C) solution of dimethylaminoethanol (3.56 g; 40.0 mmol) in THF (100

ml) in another Schenk vessel. After stirring for an hour and a half at room temperature, the mixture was again cooled to -78°C and solid p-toluenesulphonyl chloride (8.10 g; 40.0 mmol) was added slowly. The mixture was brought to 0°C and stirred at that temperature for 5 minutes, again cooled to -78°C, after which the mixture from the first Schenk vessel was added at once. After stirring for 16 hours at room temperature, the conversion was 100%. After column chromatography, 11.1 g of cyclo¬ hexyl(dimethylaminoethyl)di(2-propyl)cyclopentadiene were obtained.

Example X Example Xa: Preparation of tri(cyclohexyl)cyclopentadiene

A double-walled reactor having a capacity of 1 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 600 g (7.5 mol) of clear 50% NaOH, after which the mixture was cooled to 8°C. Then 20 g (49 mmol) of Aliquat 336 and 33 g (0.5 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 256 g (1.57 mol) of cyclohexyl bromide were added. During this process, the mixture was cooled with water. After stirring for 1 hour at room temperature, the reaction mixture was heated to 70°C, after which stirring was carried out again for 2 hours. After 2 hours, stirring was stopped and phase separation was awaited. The water layer was drained off and 600 g (7.5 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further 4 hours at 70°C. It was demonstrated with GC that 10% di- and 90% tri(cyclohexyl)cyclopentadiene were present in the mixture at that instant. The product was distilled at 0.04 mbar and 130°C. After distillation, 87.4 g of tri(cyclohexyl)cyclopentadiene were obtained.

The characterization was carried out with the aid of GC, GC-MS, 13 C- and Hϊ-NMR.

Example Xb: Preparation of (dimethylaminoethyl)tricyclohexylcyclopentadiene

The reaction was carried out in the same way as for (dimethylaminoethyl)tri(2-propyl)cyclopentadiene (Example lib). The conversion was 91%. The product was obtained as eluent via preparative silica gel column purification using petroleum ether (40 - 60°C) and THF consecutively, in a yield (hiatus?) .

Example XI

Example XIa: Preparation of tetraethylcvclopentadiene A double-walled reactor having a capacity of

1 1 and provided with a baffle, cooler, top stirrer, thermometer and dropping funnel was filled with 1050 g (13.1 mol) of clear 50% NaOH, after which the mixture was cooled to 10°C. Then 32 g (79 mmol) of Aliquat 336 and 51 g (0.77 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 344 g (3.19 mol) of ethyl bromide were added gradually in 1 hour. During this process, the mixture was cooled with water. After stirring for 1 hour at room temperature, the reaction mixture was heated to 35°C, after which stirring was carried out again for 6 hours. Stirring was stopped and phase separation was awaited. The water layer was drained off and 1050 g (13.1 mol) of fresh 50% NaOH were added. Stirring was then carried out for a further 5 hours at room temperature. It was demonstrated with GC that 15% tri-, 78% tetra- and 7% pentaethylcyclopentadiene were present in the mixture at that instant. The product was distilled at 11 mbar and 91°C. After distillation, 74.8 g of tetraethyl- cyclopentadiene were obtained. The characterization was carried out with the aid of GC, GC-MS, 13 C- and ^-H-NMR.

Example Xlb: Preparation of (dimethylaminoethyl ) - tetraethylcyclopentadiene

A solution of n-butyllithium in hexane (6.00 ml; 1.65 mol/1; 9.90 mmol) was added dropwise to a solution of tetraethylcyclopentadiene (2.066 g; 11.6 mmol) in dry THF (20 ml) in a Schenk vessel at room temperature.

Then a solution of n-butyllithium in hexane (5.90 ml; 1.65 mol/1; 9.74 mmol) was added dropwise to a cold solution (-78°C) of 2-dimethylaminoethanol

(0.867 g; 9.74 mmol) in THF (35 ml) in a second Schenk vessel. After stirring for two hours at room temperature, the mixture was again cooled to -78°C and the solid p-toluenesulphonyl chloride (1.855 g; 9.74 mmol) was added slowly. The mixture was brought to 0°C and stirred at that temperature for 5 minutes, after which the mixture from the first Schenk vessel was added at once. After 16 hours, the conversion was 100%. After column chromatography, 2.6 g of (dimethylaminoethyl)tetraethylcyclopentadiene was ob¬ tained.

Example XII

Example Xlla: Preparation of tetraoctylcyclopentadiene A double-walled reactor having a capacity of

1.5 1 and provided with baffles, cooler, top stirrer, thermometer and dropping funnel was filled with 900 g (11.3 mol) of clear 50% NaOH, after which the mixture was cooled to 10°C. Then 30 g (74 mmol) of Aliquat 336 and 48 g (0.72 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 577 g (2.99 mol) of octyl bromide was added in 1 hour. During this process, the mixture was cooled with water. After stirring for 1 hour at room temperature, the reaction mixture was heated to 35°C, after which stirring was carried out again for 6 hours. Stirring was stopped and phase

separation was awaited. The water layer was drained off and 920 g (11.5 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further 5 hours at room temperature. It was demonstrated with GC that 10% tri-, 83% tetra- and 7% pentaoctylcyclopentadiene were present in the mixture at that instant. The product was distilled at reduced pressure. After vacuum distillation, 226.6 g of tetraoctylcyclopentadiene were obtained. The product was characterized with the aid of

GC, GC-MS, 13 C- and 1 H-NMR.

Example Xllb: Preparation of

(dimethylaminoethyl )tetra(n-octyl)cvclopentadiene A solution of n-butyllithium in hexane (24.8 ml; 1.6 mol/1; 39.6 mmol) was added dropwise at room temperature to a solution of tetra(n- octyl )cyclopentadiene (20.4 g; 39.6 mmol) in dry THF (100 ml) in a Schenk vessel. Then a solution of n-butyllithium in hexane

(24.6 ml; 1.6 mol/1; 39.6 mmol) was added dropwise to a cold solution (-78°C) of 2-dimethylaminoethanol (3.53 g; 39.6 mmol) in THF (30 ml) in a second Schenk vessel. After stirring for two hours at room temperature, the mixture was again cooled to -78°C and the solid p- toluenesulphonyl chloride (7.54 g; 39.6 mmol) was added slowly. The mixture was brought to 0°C and stirred at that temperature for 5 minutes, after which the mixture from the first Schenk vessel was added at once. After 16 hours, the conversion was 87%. After column chromatography, 19.2 g of (dimethylaminoethyl)tetra(n- octyl )cyclopentadiene were obtained.

Example XIII

Example Xllla: Preparation of tetrapropylcyclopentadiene

A double-walled reactor having a capacity of 1 1 and provided with a baffle, cooler, top stirrer, thermometer and dropping funnel was filled with 1000 g (12.5 mol) of clear 50% NaOH, after which the mixture was cooled to 10°C. Then 30 g (74 mmol) of Aliquat 336 and 50 g (0.75 mol) of freshly cracked cyclopentadiene were added. The reaction mixture was vigorously stirred for several minutes. Then 373 g (3.03 mol) of propyl bromide were added in one hour. During this process, the mixture was cooled with water. After stirring for 1 hour at room temperature, the reaction mixture was heated to 35°C, after which stirring was carried out again for 6 hours. Stirring was stopped and phase separation was awaited. The water layer was drained off and 990 g (12.4 mol) of fresh 50% NaOH were added. Then stirring was carried out for a further 5 hours at room temperature. It was demonstrated with GC that 14% tri-, 80% tetra- and 6% pentapropylcyclopentadiene were present in the mixture at that instant. The product was distilled under reduced pressure. After vacuum distillation, 103.1 g of tetrapropylcyclopentadiene were obtained.

The product was characterized with the aid of GC, GC-MS, 13 C- and Η-NMR.

Example Xlllb: Preparation of (dimethylaminoethyl )- tetra(n-propyl )cyclopentadiene

A solution of n-butyllithium in hexane (93.8 ml; 1.6 mol/1; 150 mmol) was added dropwise to a solution of tetra(n-propyl )cyclopentadiene (35.0 g; 150 mmol) in dry THF (200 ml) at room temperature in a 500 ml three-neck flask.

Then a solution of n-butyllithium in hexane (93.8 ml; 1.6 mol/1; 150 mmol) was added dropwise to a

cold solution (-78°C) of 2-dimethylaminoethanol (13.35 g; 150 mmol) in THF (100 ml) in a second Schenk vessel. After stirring for 2 hours at room temperature, the mixture was again cooled to -78°C and the solid p- toluenesulphonyl chloride (28.5 g; 150 mmol) was added slowly. The mixture was brought to -20°C and stirred at that temperature for 5 minutes, after which the mixture from the first Schenk vessel was added. After 16 hours, the conversion was 97%. After column chromatography, 39.6 g of (dimethylaminoethyl )tetra(n- propyl )cyclopentadiene was obtained.