Organic compounds -- part of the class 532-570 series – Organic compounds – Silicon containing
Reexamination Certificate
2003-09-26
2004-08-17
Barts, Samuel (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Silicon containing
Reexamination Certificate
active
06777570
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a process for producing a norbornene derivative having an organosilyl group suitable as a synthetic intermediate for pesticides and medicaments and as a monomer for use in polyolefin polymers, particularly polyolefin polymers having a good adhesiveness with metals or insulating inorganic materials.
BACKGROUND OF THE INVENTION
As processes for producing a norbornene derivative having an organosilyl group, there is known a process wherein a trialkylvinylsilane and cyclopentadiene are subjected to a Diels-Alder reaction (cf. Non-patent literature 1) and a process wherein norbornadiene and a trialkylsilane are subjected to a hydrosilylation reaction (cf. Non-patent literature 2). However, these processes are not satisfactory as industrial processes because yields are as low as about 50% in both cases and also the processes require special equipments for the production since the reactions are carried out in a closed vessel having pressure resistance under a high temperature of 170° C. or higher.
In addition, the process of Non-patent literature 2 is not preferred because an expensive platinum catalyst should be used.
Furthermore, a process for producing the derivative by a Grignard reaction between trichlorosilylnorbornene and methylmagnesium bromide (Non-patent literature 3) affords a by-product having a boiling point close to that of the product, and hence is unsatisfactory as an industrial process for producing highly pure trimethylsilylnorbornene.
Moreover, the process using a substrate having a halogen atom such as chlorine atom in the molecule as the above compound is not preferred, for example, in the field where an insulating inorganic material or the like is employed, when a large amount of the halogen atom remains in the product. Accordingly, a process for producing the norbornene derivative having a higher purity has been desired.
Non-patent literature 1:
J. Org. Chem., Vol. 36 (1971), p. 929
Non-patent literature 2:
J. Org. Chem., Vol. 29 (1964), p. 2845
Non-patent literature 3:
J. Organomet. Chem., Vol. 225 (1982), p. 151
SUMMARY OF THE INVENTION
As mentioned above, in the production of a norbornene derivative having an organosilyl group, it is desired to develop a process for producing the product having a high purity in an industrially convenient and effective manner.
As a result of intensive studies for overcoming the above problems, the present inventors have found that the use of a chlorine atom as a halogen atom of a Grignard reagent results in excellent selectivity and yield of the reaction, and thus have accomplished the invention.
Namely, the gist of the invention lies in a process for producing a norbornene derivative having an organosilyl group represented by the following general formula (3):
wherein R each represents an alkyl group or an aryl group, R′ represents an alkyl group or an aryl group, n represents an integer of 0 to 2 and m represents an integer of 0 or more,
which comprises reacting a compound represented by the following general formula (1):
wherein R, n and m have the same meanings as above, and X represents a halogen atom,
with a Grignard agent represented by the following general formula (2):
R′MgCl (2)
wherein R′ has the same meaning as above.
DETAILED DESCRIPTION OF THE INVENTION
In the invention, an objective norbornene derivative having an organosilyl group is produced by reacting a norbornene compound having a halosilyl group with a specific Grignard agent.
Starting Material for Reaction
The norbornene compound having a halosilyl group to be used as a starting material for the invention is represented by the above general formula (1).
In the formula, R is specifically a linear, branched or cyclic alkyl group such as a methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, n-pentyl, n-hexyl, n-heptyl or n-octyl group; or an aryl group such as a phenyl, tolyl or xylyl group. Of these, the alkyl group has preferably from 1 to 8 carbon atoms, more preferably from 1 to 4 carbon atoms. Moreover, the aryl group has preferably from 6 to 8 carbon atoms.
X is a halogen atom such as a chlorine, bromine, or iodine atom, and is preferably a chlorine atom.
n is an integer of 0 to 2, and is preferably 0 or 1, particularly preferably 0.
m is an integer of 0 or more, and is preferably 0 or 1, particularly preferably 0.
The above compound can be easily produced by a Diels-Alder reaction between a vinylhalosilane (CH
2
═CH—SiR
n
X
3-n
) and cyclopentadiene or dicyclopentadiene. In the Diels-Alder reaction between cyclopentadiene and a vinylhalosilane, the reaction rate remarkably is increased by introducing the electron-withdrawing halogen atom and as a result, it becomes possible to lower the reaction temperature.
Examples of preferred vinylhalosilane (CH
2
═CH—SiR
n
X
3-n
) include vinyltrichlorosilane, dichloromethylvinylsilane, vinylphenyldichlorosilane, chlorodimethylsilane, diphenylvinylchlorosilane, vinylethyldichlorosilane, vinylphenylmethylchlorosilane, vinyldimethylfluorosilane, and vinyloctyldichlorosilane.
As reaction operations, a procedure generally performed in a Diels-Alder reaction may be employed. For example, in the case of using cyclopentadiene, the reaction is completed under an atmosphere of an inert gas, such as nitrogen gas or argon gas at a temperature of 30 to 150° C., preferably 50 to 100° C. for about 0.5 to 24 hours. Alternatively, in the case of using dicyclopentadiene, it is necessary to carry out the reaction at a higher temperature, for example, from 180 to 220° C.
The reaction may be carried out without solvent but is preferably carried out with a solvent in view of selectivity of the reaction. The solvent to be used is preferably a hydrocarbon solvent such as toluene or an ether solvent such as tetrahydrofuran.
In the case that m is 1 or more, the corresponding compound can be obtained by repeating the Diels-Alder reaction with cyclopentadiene two times or more times.
Grignard Agent
The Grignard reagent to be used in the invention is represented by the above general formula (2) and it is one characteristic feature of the invention that a chlorine atom is used as a halogen atom for the Grignard reagent.
In the formula, R′ may include the same groups as those exemplified as R in the above general formula (1). Of these, preferred is an alkyl group.
Preferred specific examples of the above Grignard reagent include reagents containing a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, such as methylmagnesium chloride, ethylmagnesium chloride, n-propylmagnesium chloride, i-propylmagnesium chloride, n-butylmagnesium chloride, i-butylmagnesium chloride, sec-butylmagnesium chloride, t-butylmagnesium chloride, n-pentylmagnesium chloride, neopentylmagnesium chloride, 1,1-dimethylpropylmagnesium chloride, n-hexylmagnesium chloride, 2-hexylmagnesium chloride, 3-hexylmagnesium chloride, 2-ethylbutylmagnesium chloride, n-heptylmagnesium chloride, 2-heptylmagnesium chloride, 3-heptylmagnesium chloride, 4-heptylmagnesium chloride, cyclohexylmethylmagnesium chloride, n-octylmagnesium chloride, 2-ethylhexylmagnesium chloride, cyclopropylmagnesium chloride, cyclopentylmagnesium chloride and cyclohexylmagnesium chloride. Of these, preferred is a reagent containing a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, and particularly preferred is a reagent containing a linear alkyl group having 1 to 4 carbon atoms.
The Grignard reagent may be used as a commercially available one or may be prepared in accordance with a known method from a corresponding alkyl chloride. Namely, it is obtained by placing activated magnesium metal in an ether solvent such as anhydrous diethyl ether or anhydrous tetrahydrofuran at a temperature of 0 to 100° C., preferably 10 to 50° C., adding dropwise the alkyl chloride under stirring, and continuing the stirring for further 0.1 to 8 hours.
The magnesium metal to be used in the reaction may be commercially available tape-shaped or chip-shaped one and the amount thereof to be used
Ichikawa Shuji
Naito Taketoshi
Takahashi Hiroko
Takahashi Takako
Barts Samuel
Mitsubishi Chemical Corporation
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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