JP2015044769A - Method for producing silylamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a silylamine with higher efficiency and at lower cost than a conventional method.SOLUTION: There is provided a method for producing a silylamine in which RRRSiNRRis obtained by reacting a disilazane represented by RRRSiNHSiRRR(provided that R, Rand Reach independently represent an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms) and an amine represented by RRNH (provided that Rand Reach independently represent an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or a phenyl group) in the presence of a non-protonic highly polar solvent and a strong acid or an ammonium salt thereof.

Description

  The present invention relates to a method for producing a silicon compound, particularly silylamine, which is an organosilicon compound having a Si—N bond.

The silylamine compound represented by the general formula R ₃ SiNR ′ ₂ is useful as a precursor for forming a silicon nitride film by CVD or as a special silylating agent. As a general production method for synthesizing a silylamine compound, as disclosed in Non-Patent Document 1, it is known to react a trialkylchlorosilane such as trimethylchlorosilane with a dialkylamine such as dimethylamine or dibutylamine.

Szabo, Katalin; Le Ha, Ngoc; Schneider, Phillippe; Zeltner, Peter; sz. Kovacs, Ervin, Helvetica Chimica Acta, 1984, vol. 67, p. 2128-2142

  However, when silylamine is produced by reaction of trialkylchlorosilane and dialkylamine, dialkylamine is used in an equivalent amount of chlorosilane more than twice, and reacted in an anhydrous aprotic organic solvent such as toluene or hexane, A technique is required in which hydrogen chloride produced by the reaction is trapped as the hydrochloride of the amine, and the hydrochloride of the amine produced as a by-product is removed by filtration, and then the solvent and the silylamine produced are separated and purified by distillation. In this method, an amine hydrochloride equivalent to the target silylamine is produced, so that the dialkylamine used as a raw material is required to be twice as much mole as chlorosilane with respect to chlorosilane, and stirring for smooth reaction. For this reason, a considerable amount of solvent is required, so that the production efficiency is limited, and further, the process of filtration of amine hydrochloride is necessary and the process is complicated.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to provide a method for producing silylamine more efficiently and at a lower cost than conventional methods.

The method for producing silylamine according to the present invention is a disilazane represented by R ¹ R ² R ³ SiNHSiR ¹ R ² R ³ (where R ¹ , R ² and R ³ are each independently an alkyl having 1 to 3 carbon atoms). Group or an alkenyl group having 2 to 3 carbon atoms).
An amine represented by R ⁴ R ⁵ NH (wherein R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or a phenyl group); The
Reacting in the presence of an aprotic strong polar solvent and a strong acid or its ammonium salt to obtain R ¹ R ² R ³ SiNR ⁴ R ⁵ .

  Here, it is preferable that 0.1 mol or more of a strong acid or its ammonium salt is present with respect to 100 mol of disilazane.

  Further, it is preferable that 5 parts by mass or more of an aprotic strong polar solvent is present with respect to 100 parts by mass of disilazane.

  According to the production method of the present invention, a highly efficient and low cost synthesis method of silylamine is provided.

The method for producing silylamine according to the present invention comprises a disilazan represented by R ¹ R ² R ³ SiNHSiR ¹ R ² R ³ , an amine represented by R ⁴ R ⁵ NH, an aprotic strong polar solvent, and a strong acid. Alternatively, the reaction is carried out in the presence of an ammonium salt thereof to obtain silylamine R ¹ R ² R ³ SiNR ⁴ R ⁵ .

(Disilazan)
Disilazane ^{R 1 R 2 R 3 SiNHSiR 1} R 2 R R 1 in the formula ^{3, R 2} and ^{R 3} are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms Indicates.

R ¹ , R ² , and R ³ may all be the same as each other, only ^{two of} R ¹ , R ² , and R ³ may be the same, or any of R ¹ , R ^2, and R ³ may be May be different from each other.

Specific examples of R ¹ , R ² , and R ³ include a methyl group, an ethyl group, a propyl group, a vinyl group, and an allyl group. The most common disilazane is hexamethyldisilazane in which R ¹ , R ² and R ³ are all methyl groups, but the reaction is not limited to this.

(Amine)
^{R 4} and ^{R 5} in the formula of the amine ^R 4 ^R 5 NH represents each independently an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or a phenyl group.

R ⁴ and R ⁵ may be the same as each other or different from each other. Examples of R ⁴ and R ⁵ are dimethylamine, diethylamine, diisopropylamine, dibutylamine, N-methylcyclohexylamine, methylphenylamine, diallylamine and the like.

(Aprotic strong polar solvent)
Examples of aprotic strong polar solvents include N, N-dimethylformamide, N-methylpyrrolidone, dimethylethyleneurea, hexamethylphosphoric triamide (HMPA) and other amide solvents; dimethyl sulfoxide (DMSO); acetonitrile and the like. can give. This aprotic strong polar solvent acts as a co-catalyst and the reaction does not proceed without it. The addition amount of the aprotic strong polar solvent is not particularly limited, but it is preferably 5 parts by mass or more, and preferably 10 parts by mass or more with respect to 100 parts by mass of disilazane. There is no particular upper limit on the amount of the aprotic strong polar solvent added. For example, at the start of the reaction, the amount is preferably 200 parts by mass or less, more preferably 100 parts by mass or less with respect to 100 parts by mass of disilazane. . The amount added is determined in consideration of the reaction vessel efficiency and reaction rate.

(Strong acid or its ammonium salt)
Examples of strong acids are inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and organic acids such as p-toluenesulfonic acid and dodecylbenzenesulfonic acid. In this reaction, amine is added, so these acids are considered to be ammonium salts of amine added at the start of the reaction, but in fact, the same effect can be obtained by adding ammonium salt of strong acid instead of strong acid itself. can get. The ammonium salt is not necessarily an amine salt to be added, and the same results can be obtained with ammonium salts such as ammonium chloride and ammonium sulfate derived from ammonia.

  In this reaction, a strong acid or its ammonium salt acts as a catalyst for the reaction. The addition amount of the strong acid or its ammonium salt is not particularly limited, but it is preferably 0.1 mol or more, more preferably 0.5 mol or more with respect to 100 mol of disilazane. Although there is no particular upper limit of the amount added, it is preferably 10 mol or less, more preferably 5 mol or less with respect to 100 mol of disilazane at the start of the reaction. If the amount is less than 0.1 mol, the reaction may be delayed and the production efficiency may be slightly lowered. If the amount exceeds 10 mol, not only the catalyst is wasted but also the efficiency in the filtration step may be deteriorated.

(Reaction operation)
Either disilazan may be added to the mixture of amine and catalyst system component (aprotic strong polar solvent and strong acid or its ammonium salt), or amine may be added to the mixture of disilazane and catalyst system component. However, the target silylamine can be obtained. It is preferable to remove ammonia generated during the reaction out of the reaction system. As a method of removing it outside the reaction system, a fractionation tower can be mentioned.

  Although reaction temperature is not specifically limited, 10-125 degreeC is preferable. The reaction pressure is not particularly limited, and the reaction can be performed under normal pressure. Although the reaction can be promoted by increasing the temperature under pressure, it is necessary to devise a device for efficiently removing the produced ammonia out of the system.

(effect)
According to the production method of the present invention, a strong acid or an ammonium salt thereof serves as a catalyst, and an aprotic strong polar solvent serves as a promoter to react silazane with a dialkylamine to produce silylamine. The reaction occurs mainly in a liquid phase containing a solvent. Ammonia is produced as a by-product of the reaction. However, removing ammonia, which is a gas, from a solvent (liquid phase) is much more difficult than removing salt, which is a by-product, from a solvent by filtration or the like as in the conventional method. Easy to. Therefore, high efficiency and low cost are achieved, and it is useful as an industrial process for synthesizing silylamine.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example 1
A 300 ml four-necked flask equipped with a stir bar, thermometer, reflux tube, and gas introduction tube was charged with 161 g (1 mol) of hexamethyldisilazane, 50 g of dimethylethyleneurea manufactured by Kawaken Fine Chemicals, and 1.32 g of ammonium sulfate (0 .01 mol) was added and heating and stirring were started. When the temperature exceeded 40 ° C., dimethylamine was introduced into the system through a gas introduction tube while stirring. Dimethylamine was further introduced while confirming the progress of the reaction by gas chromatography, and it was confirmed that hexamethyldisilazane was completely consumed and trimethylsilyldimethylamine was produced. Thereafter, atmospheric distillation was performed to obtain 200 g (1.71 mol) of trimethylsilyldimethylamine having a boiling point of 86 ° C. The yield was 85%.

Example 2
A 500 ml four-necked flask equipped with a stir bar, thermometer, reflux tube and dropping funnel was charged with 161 g (1 mol) of hexamethyldisilazane, 50 g of dimethylethyleneurea manufactured by Kawaken Fine Chemicals, and 0.98 g of concentrated sulfuric acid (0 .01 mol) was added and heating and stirring were started. When the temperature exceeded 40 ° C., dimethylamine was introduced into the system through a gas introduction tube while stirring. Dimethylamine was further introduced while confirming the progress of the reaction by gas chromatography, and it was confirmed that hexamethyldisilazane was completely consumed and trimethylsilyldimethylamine was produced. Thereafter, atmospheric distillation was performed to obtain 210 g (1.79 mol) of trimethylsilyldimethylamine having a boiling point of 86 ° C. The yield was 90%.

Example 3
A 500 ml four-necked flask equipped with a stir bar, thermometer, reflux tube and dropping funnel was charged with 161 g (1 mol) of hexamethyldisilazane, 50 g of dimethylethyleneurea manufactured by Kawaken Fine Chemicals, and 3.3 g of dodecylbenzenesulfonic acid. (0.01 mol) was added and heating and stirring were started. When the temperature exceeded 40 ° C., dimethylamine was introduced into the system through a gas introduction tube while stirring. Dimethylamine was further introduced while confirming the progress of the reaction by gas chromatography, and it was confirmed that hexamethyldisilazane was completely consumed and trimethylsilyldimethylamine was produced. Thereafter, atmospheric distillation was performed to obtain 220 g (1.88 mol) of trimethylsilyldimethylamine having a boiling point of 86 ° C. The yield was 94%.

Example 4
A 500 ml four-necked flask equipped with a stir bar, thermometer, reflux tube and dropping funnel was charged with 161 g (1 mol) of hexamethyldisilazane, 50 g of N-methylpyrrolidone, 3.3 g of dodecylbenzenesulfonic acid (0.3 g). 01 mol) was added and heating and stirring were started. When the temperature exceeded 40 ° C., dimethylamine was introduced into the system through a gas introduction tube while stirring. Dimethylamine was further introduced while confirming the progress of the reaction by gas chromatography, and it was confirmed that hexamethyldisilazane was completely consumed and trimethylsilyldimethylamine was produced. Thereafter, atmospheric distillation was performed to obtain 195 g (1.66 mol) of trimethylsilyldimethylamine having a boiling point of 86 ° C. The yield was 83%.

Claims (4)

Disilazan represented by R ¹ R ² R ³ SiNHSiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 3 carbon atoms, or having 2 to 3 carbon atoms) An alkenyl group.)
An amine represented by R ⁴ R ⁵ NH (wherein R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or a phenyl group); The
A method for producing silylamine, which is reacted in the presence of an aprotic strong polar solvent and a strong acid or an ammonium salt thereof to obtain R ¹ R ² R ³ SiNR ⁴ R ⁵ .   The process according to claim 1, wherein 0.1 mol or more of a strong acid or its ammonium salt is present per 100 mol of disilazane.   The method according to claim 1 or 2, wherein 5 parts by mass or more of an aprotic strong polar solvent is present with respect to 100 parts by mass of disilazane. The method according to any one of claims 1 to ³ , wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are all methyl groups.