JP2690035B2 - Process for producing N-[(bissilyl-substituted aryl) methylidene] amines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a silicon-containing azomethine compound using a novel reaction, more specifically, N-[(bissilyl-substituted aryl) methylidene useful as a synthetic intermediate for agricultural chemicals, pharmaceuticals and various fine chemical products. ] The present invention relates to a method for producing amines by utilizing a new reaction.

[0002]

2. Description of the Related Art Azomethine compounds, so-called Schiff bases, can be converted into amine compounds by reduction, and can also be converted into various nitrogen-containing compounds by utilizing an addition reaction to a carbon-nitrogen double bond. It is used in various fields as a raw material and intermediate for various organic synthetic products such as agricultural chemicals and pharmaceuticals. On the other hand, as interest in silicon-containing organic compounds has increased in recent years, methods for introducing silicon-containing substituents into various basic skeletons have been studied due to the requirements for molecular design, and tri-substituted silyl groups can be easily removed by reduction. Therefore, attention has been paid also from the viewpoint of the function as a protecting group, and a simple method for producing a compound having a tri-substituted silyl group has been demanded.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a novel azomethine compound by introducing a tri-substituted silyl group as a silicon-containing substituent into an azomethine compound which is important as a synthetic intermediate for various useful compounds. It was made for the purpose of doing.

[0004]

Means for Solving the Problems As a result of various studies on the method for obtaining silicon-containing azomethine, the present inventors have found that
By reacting aromatic azomethine with disilane, two tri-substituted silyl groups can be unexpectedly introduced into the aromatic ring of aromatic azomethine, and N-[(bissilyl-substituted aryl) methylidene] amines can be easily prepared. They have found that they can be obtained, and have completed the present invention based on this finding.

That is, the present invention provides a compound represented by the general formula (Ar in the formula may be substituted with a halogen atom, an alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, an amino group or a sulfonyl group, which has at least two hydrogen atoms on the aromatic ring. Aromatic azo group, R is a halogen atom, an alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, a hydrocarbon group which may be substituted with an amino group or a sulfonyl group) Mol and the general formula

Embedded image 2 moles or more of a disilane represented by the formula (R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are an alkyl group, an aryl group or an aralkyl group which may have a substituent). A general formula characterized by reacting (In the formula, Ar 'means that two hydrogen atoms of Ar are -SiR ¹ R ²
Aromatic ring group substituted by R ³ and —SiR ⁴ R ⁵ R ⁶ , R, R
¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ have the same meanings as described above, and a method for producing N-[(bissilyl-substituted aryl) methylidene] amines.

In the method of the present invention, the aromatic azomethine of the above-mentioned general formula (I) used as one of the starting materials is such that the group Ar bonded to the methylidene group is an aromatic ring group such as a phenyl group or a naphthyl group. Well, there are no other special restrictions. That is, since the reaction in the method of the present invention is a substitution reaction between a hydrogen atom of an aromatic ring group bonded to a methylidene group and a tri-substituted silyl group, a hydrocarbon group R bonded to a nitrogen atom of azomethine is saturated or It may be any of an unsaturated aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group and an araliphatic hydrocarbon group, and these hydrocarbon groups may be a halogen atom, an alkyl group or an alkoxy group. It may be substituted with a carboxyl group, an alkoxycarbonyl group, an acyl group, an amino group or a sulfonyl group. Similarly, in Ar as well, the remaining hydrogen atoms may be substituted with the above-mentioned substituents, except for the positions where two tri-substituted silyl groups are introduced.

Therefore, examples of Ar include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, or a biphenyl group, and at least some of the remaining hydrogen atoms of these groups except a halogen atom or an alkyl group. , Those substituted with an alkoxy group, an alkoxycarbonyl group, an acyl group, a carboxyl group and the like.

Further, R is a methyl group, an ethyl group, an isopropyl group, an n-propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a hexyl group, an octyl group, a decyl group or a dodecyl group. Group, stearyl group, eicosyl group, cyclopentyl group, linear group such as cyclohexyl group, branched alkyl group or cycloalkyl group, allyl group, butenyl group, alkenyl group such as hexenyl group, phenyl group, naphthyl group, Examples thereof include an aryl group such as a biphenyl group, an aralkyl group such as a benzyl group, a phenethyl group, and a phenylpropyl group, and those in which a part of hydrogen atoms of these groups are substituted with the above-described substituents.

That is, specific examples of the aromatic azomethine represented by the general formula (I) include, for example, N-benzylidenemethylamine, N-benzylideneethylamine,
N-benzylideneisopropylamine, N-benzylidene-n-butylamine, N-benzylidene-t-butylamine, N-benzylidenedecylamine, N-benzylidenebenzylamine, N-benzylidenephenethylamine, N- (1-naphthylidene) methylamine, N -
(2-naphthylidene) methylamine, p-tolualdehydemethylimine, 4-fluorobenzaldehydemethylimine, 3,4-dimethoxybenzaldehydemethylimine, 4-acetoxybenzaldehydemethylimine,
4-methoxycarbonylbenzaldehyde methylimine, N-benzylidene (methoxymethyl) amine, 2-
Methyl (N-benzylideneamino) propionate, N-
Examples thereof include benzylidene (3-ethoxycarbonylpropyl) amine and N-benzylidene (trifluoromethyl) amine.

The disilane used as the other raw material in the method of the present invention is a compound represented by the above general formula (II), wherein R ¹ to R ⁶ are each an alkyl group, an aryl group or an aralkyl group. It is a hydrocarbon group. Here, the alkyl group may be linear, branched, or cyclic, and specifically, a methyl group, an ethyl group,
n-propyl group, isopropyl group, n-butyl group, se
Examples thereof include c-butyl group, t-butyl group, hexyl group, octyl group, cyclopentyl group, cyclohexyl group and the like. These alkyl groups may have an appropriate substituent, and examples of the substituent include a halogen atom and an alkoxy group. Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the arylalkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, and a naphthylmethyl group. Further, these aryl group and aralkyl group may have an appropriate substituent, and examples of the substituent include a halogen atom, an alkyl group and an alkoxy group. R ¹ to R ⁶ may be the same or different.

Therefore, examples of the hexa-substituted disilanes represented by the general formula (II) include hexamethyldisilane, 1-phenyl-1,1,2,2,2-pentamethyldisilane and 1,2-diphenyl. -1, 1, 2, 2
-Tetramethyldisilane, hexaethyldisilane, 1,
2-diethyl-1,1,2,2-tetramethyldisilane, hexaphenyldisilane, 1,1-diphenyl-
1,2,2,2-tetramethyldisilane, 1,1,1-
Triphenyl-2,2,2-trimethyldisilane, 1,
1,2-triphenyl-1,2,2-trimethyldisilane, 1,1,2,2-tetraphenyl-1,2-dimethyldisilane, 1,1,1,2,2-pentaphenyl-2
-Methyldisilane, 1-phenyl-1,1,2,2,2
-Pentaethyldisilane, 1,2-diphenyl-1,2
-Dipropyl-1,2-dimethyldisilane, 1,2-dibenzyl-1,1,2,2-tetramethyldisilane and the like can be mentioned.

In the method of the present invention, these hexa-substituted disilanes are used in an amount of 2 moles per 1 mole of the aromatic azomethine.
It is necessary to use it in a molar ratio of 2 to 100 mol, preferably 2-1 to 1 mol of aromatic azomethine.
It is advantageous to use it in a proportion of 0 mol.

In this reaction, a catalyst can be used if necessary. As this catalyst, a palladium complex, a platinum complex, a nickel complex and the like are suitable.
As these complexes, conventionally known ones can be used, but it is preferable to use a compound at least partially soluble in the reaction system in terms of the reaction rate. It is particularly preferred that these complexes contain an organic ligand, such as phosphine, phosphinite, phosphonite, phosphite, olefin, β-diketonato ligand, conjugated ketone, nitrile, amine Carboxylate ligand, carbon monoxide and the like.

Examples of the organic ligand include trimethylphosphine, tributylphosphine, triethylphosphine, tricyclohexylphosphine, triphenylphosphine, tri (p-tolyl) phosphine, tri (p-tolyl) phosphine.
Chain phosphines such as -anisyl) phosphine, diphenylmethylphosphine, phenyldimethylphosphine, P-methylphospholene, P-methylphosphol, 9
Phosphines such as 1-methyl-9-phosphabicyclo [4.2.1] nonane, 1,2-bis (dimethylphosphino) ethane, 1,2-bis (diethylphosphino) ethane, 1,3-bis (Diphenylphosphino) propane, 1,4-bis (diphenylphosphino) butane,
1,1′-bis (dimethylphosphino) ferrocene,
1,1'-bis (diphenylphosphino) ferrocene,
bisphosphines such as α, α′-bis (dimethylphosphino) -o-xylene and 1,2-bis (dimethylphosphino) benzene, methyl dimethylphosphinite,
Phosphinites such as phenyl diphenylphosphinite, phosphonites such as dimethyl methylphosphonite and dimethylphenylphosphonite, triethyl phosphite, triphenyl phosphite, and 1-phospha-
2,6,7-trioxa-4-ethylbicyclo [2.
2.2] phosphites such as octane, ethylene, propylene, cyclooctene, maleic anhydride, 1,5-hexadiene, 1,5-cyclooctadiene, 1,3-cyclopentadiene, 2,5-norbornadiene, 1,3,3
Olefins such as 5,7-cyclooctatetraene, dienes, β-diketonato ligands such as acetylacetonate, conjugated ketones such as dibenzylideneacetone, nitriles such as acetonitrile and benzonitrile, ethylenediamine, 2,2'-bipyridyl And carboxylato ligands such as acetonate.

Specific examples of the palladium complex, platinum complex and nickel complex used as the catalyst in the method of the present invention include tetrakis (triphenylphosphine) palladium, tetrakis (diphenylmethylphosphine) palladium, dichlorobis (trimethylphosphine) palladium and dichlorobis. (Triethylphosphine) palladium, dichlorobis (triphenylphosphine) palladium, dichlorobis (phenyldimethylphosphine) palladium, dichloro [1,2-bis (dimethylphosphino) ethane] palladium, dichloro [1,3-bis (diphenylphosphino)] Propane] palladium, dichloro [1,4-bis (diphenylphosphino) butane] palladium, dichloro [1,2-bis (diethylphosphino) ethane] paradi Arm, dichloro [1,1'-bis (diphenylphosphino) ferrocene] palladium, bis (dibenzylideneacetone) palladium, tris (dibenzylideneacetone) dipalladium, dichloro (.eta.
1,5-cyclooctadiene) palladium, bis (η-
Allyl) palladium, (η-ethylene) bis (triphenylphosphine) palladium, dichlorobis (benzonitrile) palladium, dichloroethylenediaminepalladium, palladium acetate, (η-ethylene) bis (triphenylphosphine) platinum, tetrakis (triphenylphosphine) Platinum, tetrakis (diphenylmethylphosphine) platinum, tetrakis (triethylphosphine) platinum, dichlorobis (triphenylphosphine) platinum, dibromobis (triethylphosphite) platinum, bis (η
-1,5-cyclooctadiene) platinum, dichloro (η-
1,5-cyclooctadiene) platinum, dicarbonylbis (tributylphosphine) platinum, carbonatobis (tricyclohexylphosphine) platinum, bis (dibenzylideneacetone) bis (triphenylphosphine) platinum, tris (dibenzylideneacetone) diplatinum, Dichlorobis (benzonitrile) platinum, dichlorobis (acetonitrile) platinum, tetrakis (triphenylphosphine) nickel, tetrakis (diphenylmethylphosphine) nickel, tetrakis (triethylphosphine) nickel,
Dichlorobis (trimethylphosphine) nickel, dichlorobis (triethylphosphine) nickel, dichlorobis (triphenylphosphine) nickel, dichlorobis (phenyldimethylphosphine) nickel, dichloro [1,2-bis (dimethylphosphino) ethane] nickel, dichloro [1, 3-bis (diphenylphosphino)
Propane] nickel, dichloro [1,4-bis (diphenylphosphino) butane] nickel, dichloro [1,2
-Bis (diethylphosphino) ethane] nickel, dichloro [1,1'-bis (diphenylphosphino) ferrocene] nickel, bis (η-1,5-cyclooctadiene) nickel, dimethylbis (trimethylphosphine)
Nickel, diethyl (2,2′-bipyridyl) nickel, bis (η-allyl) nickel, (η-ethylene) bis (triphenylphosphine) nickel, bis (acetylacetonato) nickel and the like can be mentioned.

In the method of the present invention, each of these complexes may be used alone or in combination of two or more, and together with these complexes, the same or different from the one contained in the complex. One or more ligands may be added to the reaction system. The amount of these complexes used may be a so-called catalytic amount, and is usually 0.
It is selected in the range of 00001 to 0.5 mol. When a ligand is added together with the complex, the amount thereof is 1 to 2 in terms of molar ratio to the palladium, platinum or nickel atom in the complex.
It is desirable to select it in the range of 0.

In the method of the present invention, the reaction can be easily carried out without using a solvent, but the reaction may be carried out in a solvent if necessary. As this solvent, in consideration of the reactivity of the aromatic azomethine and hexa-substituted disilane to be reacted, for example, an aromatic hydrocarbon system,
It is advantageous to choose among solvents such as saturated aliphatic or saturated alicyclic hydrocarbons and alkyl ethers.

Although the reaction in the method of the present invention proceeds even at 0 ° C. or lower, it can be heated to a temperature of about 250 ° C. to increase the reaction rate. From the viewpoints of reaction rate and suppression of side reactions, the preferable reaction temperature is generally in the range of 0 to 200 ° C, and particularly preferably in the range of 100 to 200 ° C, although it depends on the kind of the starting materials used. .

The separation of the product after the completion of the reaction can be carried out by a commonly used known means such as distillation, recrystallization and chromatography.

Thus, the N-[(bissilyl-substituted aryl) methylidene] amines represented by the general formula (III) can be efficiently obtained. The N-[(bissilyl-substituted aryl) methylidene] amines are all novel compounds that have not been published in the literature.

[0021]

INDUSTRIAL APPLICABILITY The method of the present invention is a method utilizing a novel reaction. According to this method, N which is useful as a synthetic intermediate for various fine chemical products such as agricultural chemicals and pharmaceuticals.
-[(Bissilyl-substituted aryl) methylidene] amines can be efficiently produced by a one-step reaction using easily available starting materials.

[0022]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

Example 1 Tris (dibenzylideneacetone) diplatinum 0.005
mmol, 1-phospha-2,6,7-trioxa-4
-Ethylbicyclo [2.2.2] octane 0.017
mmol, N-benzylidenemethylamine 0.5 mm
A mixture of ol, hexamethyldisilane (1.5 mmol) and toluene (0.1 ml) was placed in a glass sealed tube under nitrogen and heated to 160 ° C. for 5 days. As a result of analyzing by gas chromatography after opening, N- represented by the following formula
It was confirmed that [2,6-bis (trimethylsilyl) benzylidene] methylamine was produced at a yield of 83% (based on N-benzylidenemethylamine).

[0024]

Embedded image

This compound was isolated by distillation after the reaction solution was concentrated and identified by the following analytical data. ¹ H-NMR (C ₆ D ₆ ) (ppm); δ 8.68
(D, J = 1.1 Hz, 1H), 7.62 (d, 2
H), 7.36 (m, 1H), 3.49 (d, J = 1.
5 Hz, 3 H), 0.29 (s, 18 H) ¹³ C-NMR (C ₆ D ₆ ) (ppm); δ 164.3.
148.0, 139.3 (2C), 135.8 (2
C), 127.6, 47.0, 1.3 (6C) ²⁹ Si-NMR (C ₆ D ₆ ) (ppm); δ-5.3 GC-MS; 263 (M ⁺ , 1), 248 ( 100) IR (cm ^-1 ); 2960, 2902, 1661, 12
51,874,835 Elemental analysis value: C ₁₄ H ₂₅ NSi ₂ theoretical value (%) C 63.81, H 9.56, N
5.35 Measured site (%) C 63.64, H 9.69, N
5.22

Example 2 The reaction was carried out in the same manner as in Example 1 except that p-tolualdehydemethylimine was used in place of N-benzylidenemethylamine, and gas chromatographic analysis revealed that it was 2,6 -Bis (trimethylsilyl) -4-
It was found that methylbenzaldehyde methylimine was produced in a yield of 82% (based on p-tolualdehydemethylimine). This compound was isolated by distillation after concentrating the reaction solution, and its spectral data was as follows.

[0027]

Embedded image

¹ H-NMR (C ₆ D ₆ ) (ppm); δ
8.65 (d, J = 1.5 Hz, 1H), 7.43
(S, 2H), 3.47 (d, J = 1.5Hz, 3
H), 2.37 (s, 3H), 0.29 (s, 18H) ¹³ C-NMR (C ₆ D ₆ ) (ppm); δ 163.9,
139.3 (2C), 139.1, 137.2, 13
6.6 (2C), 46.9, 21.6, 1.3 (6C) ²⁹ Si-NMR (C ₆ D ₆ ) (ppm); δ -5.7.

Example 3 A reaction was conducted in the same manner as in Example 1 except that 4-fluorobenzaldehyde methylimine was used in place of N-benzylidenemethylamine, and gas chromatographic analysis revealed that it was 2,6 9-bis (trimethylsilyl) -4-fluorobenzaldehyde methylimine
It was found that the yield was 2% (based on 4-fluorobenzaldehyde methylimine). This compound was isolated by distillation after concentrating the reaction solution, and its spectral data was as follows.

[0030]

Embedded image

¹ H-NMR (C ₆ D ₆ ) (ppm); δ
8.61 (d, J = 1.6 Hz, 1H), 7.27
(D, J = 9.2 Hz, 1H), 3.47 (d, J =
1.5 Hz, 3H), 0.29 (s, 18H) ¹³ C-NMR (C ₆ D ₆ ) (ppm); δ 162.8
(D, J = 253 Hz), 162.8, 143.3
(D, J = 3.6 Hz, 2C), 122.1 (d, J =
19.6 Hz, 2 C), 46.7, 1.1 (6 C) ²⁹ Si-NMR (C ₆ D ₆ ) (ppm); δ −5.7.
(D, J = 1.4Hz)

Claims (3)

(57) [Claims] 1. The general formula (Ar in the formula may be substituted with a halogen atom, an alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, an amino group or a sulfonyl group, which has at least two hydrogen atoms on the aromatic ring. Aromatic azo group, R is a halogen atom, an alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, a hydrocarbon group which may be substituted with an amino group or a sulfonyl group) Mol and the general formula 2 moles or more of a disilane represented by the formula (R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are an alkyl group, an aryl group or an aralkyl group which may have a substituent). A general formula characterized by reacting (In the formula, Ar 'means that two hydrogen atoms of Ar are -SiR ¹ R ²
Aromatic ring group substituted by R ³ and —SiR ⁴ R ⁵ R ⁶ , R, R
¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ have the same meanings as defined above, and a process for producing N-[(bissilyl-substituted aryl) methylidene] amines. 2. The production method according to claim 1, wherein the reaction is carried out in the presence of a catalyst. 3. The method according to claim 2, wherein the catalyst is at least one selected from a palladium complex, a platinum complex and a nickel complex.