CN110862408A

CN110862408A - Synthesis method of N-alkyl aza-silacyclopentane and N-alkyl aza-silacyclopentane

Info

Publication number: CN110862408A
Application number: CN201911207285.5A
Authority: CN
Inventors: 李胜杰; 冯琼华; 肖俊平
Original assignee: HUBEI BLUESKY NEW MATERIAL Inc
Current assignee: HUBEI BLUESKY NEW MATERIAL Inc
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-03-06

Abstract

The invention discloses a method for synthesizing N-alkyl aza-silacyclopentane and N-alkyl aza-silacyclopentane, relating to the technical field of organic silicon materials. The main raw material of the synthesis method is amino trialkoxysilane, the raw material is simple and easy to obtain, and only a byproduct methanol is generated in the reaction process, so that the synthesis method is safe, environment-friendly and easy to treat. The synthesis method provided by the invention has the advantages that the product content can reach more than 97%, and the yield is more than 85%.

Description

Synthesis method of N-alkyl aza-silacyclopentane and N-alkyl aza-silacyclopentane

Technical Field

The invention relates to the technical field of organic silicon materials, and particularly relates to a synthetic method of N-alkyl azasilacyclopentane and N-alkyl azasilacyclopentane.

Background

The N-alkyl aza-silicon cyclopentane has both high-reactivity aza-silicon ring and hydrolyzable alkoxy, so it can be widely used in bonding, resin modification, single-component RTV, etc. tertiary nitrogen makes it possess better anti-yellowing property. However, no synthesis method for N-alkyl azasilacyclopentane suitable for industrial production is found in the industry, and some documents propose a synthesis method for N-alkenyl azasilacyclopentane, which is mainly synthesized by heating aminotrialkoxysilane and hexamethyldisilazane under the action of a catalyst, and by-products of ammonia gas and trimethylmethoxysilane are generated in the reaction process.

Therefore, a technical scheme capable of synthesizing N-alkyl azasilacyclopentane is needed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a synthetic method of N-alkyl azasilacyclopentane and N-alkyl azasilacyclopentane which has good yellowing resistance.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: a synthetic method of N-alkyl aza-silacyclopentane comprises the following steps:

taking amino trialkoxysilane as a raw material, and removing methanol under the high-temperature strong-alkaline condition for synthesis.

On the basis of the technical scheme, the amino trialkoxysilane is silane containing amino and trialkoxy, and is one or more of n-butyl aminopropyl trimethoxysilane, methacrylic aminopropyl trimethoxysilane and aminoethyl aminopropyl trimethoxysilane.

On the basis of the technical scheme, 100 parts by mass of amino trialkoxysilane and 1-3 parts by mass of catalyst are put into a reaction container, stirring is started, a reaction system keeps negative pressure, and the temperature of the reaction container is kept at 130-150 ℃ for full reflux reaction;

after reacting for 3-5 h, obtaining a target product when the top temperature tends to be stable.

On the basis of the technical scheme, the reaction container adopts a three-mouth flask and is provided with a filler column and a rectifying head.

On the basis of the technical scheme, the catalyst is a strong basic catalyst.

On the basis of the technical scheme, the catalyst is one of sodium methoxide, potassium methoxide, magnesium methoxide, sodium amide, potassium amide and magnesium amide.

On the basis of the technical scheme, the full reflux reaction is carried out under the negative pressure of less than-0.095 MPa during the reaction.

The invention also provides N-alkyl aza-silacyclopentane, which comprises the following raw materials in parts by mass:

100 parts by mass of an aminotrialkoxysilane;

1-3 parts by mass of a strong basic catalyst.

On the basis of the technical scheme, the chemical structural formula of the N-alkyl aza-silacyclopentane is as follows:

wherein R1 is methyl, ethyl or propyl, and R2 is alkyl, alkenyl or phenyl.

On the basis of the technical scheme, the N-alkyl aza-silacyclopentane is one or more of N-N-butyl-aza-2, 2-dimethoxy silacyclopentane, 1-dimethoxy-2-methylpropene-2-aza-1 silacyclopentane and N-aminoethyl-aza-2, 2-dimethoxy silacyclopentane.

Compared with the prior art, the invention has the advantages that:

the invention takes amino trialkoxysilane as a raw material, removes methanol under the condition of high temperature and strong alkalinity to synthesize N-alkyl aza-silacyclopentane, and the silane has both high-reactivity aza-silacycle and hydrolyzable alkoxy, so the silane can be widely used for bonding, resin modification, single-component RTV and the like, and tertiary nitrogen enables the silane to have better yellowing resistance. The main raw material of the synthesis method is amino trialkoxysilane, the raw material is simple and easy to obtain, only a byproduct methanol is generated in the reaction process, the synthesis method is safe, environment-friendly and easy to treat, the content of the product can reach more than 97 percent, and the yield is more than 85 percent.

Detailed Description

The embodiment of the invention provides a method for synthesizing N-alkyl aza-silacyclopentane, which comprises the following steps:

taking amino trialkoxysilane as a raw material, and removing methanol under the high-temperature strong-alkaline condition to synthesize the N-alkyl aza-silacyclopentane.

The amino trialkoxy silane is silane containing amino and trialkoxy, and is one or more of n-butyl aminopropyl trimethoxy silane, methacrylic aminopropyl trimethoxy silane and aminoethyl aminopropyl trimethoxy silane.

The N-alkyl azasilacyclopentane is one or more of N-N-butyl-aza-2, 2-dimethoxy silacyclopentane, 1-dimethoxy-2-methylpropene-2-aza-1 silacyclopentane and N-aminoethyl-aza-2, 2-dimethoxy silacyclopentane.

The synthesis method specifically comprises the following steps:

(1) a reaction device: a 1L three-neck flask, a magnetic stirrer, a thermometer, a packed column with 30cm and a rectifying head.

(2) 100g of aminotrialkoxysilane and 1-3 g of a catalyst were charged into a reaction vessel.

(3) Starting stirring and heating, keeping the negative pressure of a reaction system to be less than-0.095 MPa, and keeping the temperature of a kettle to be 130-150 ℃ for full reflux reaction.

(4) The top temperature is lower and lower along with the reaction, and the target product can be obtained after the reaction is carried out for 3-5 h and the top temperature is stable.

Wherein the catalyst is a strongly basic catalyst. The catalyst is one of sodium methoxide, potassium methoxide, magnesium methoxide, sodium amide, potassium amide and magnesium amide.

The embodiment of the invention also provides N-alkyl aza-silacyclopentane, which comprises the following raw materials in parts by mass:

100 parts by mass of an aminotrialkoxysilane;

1-3 parts by mass of a strong basic catalyst.

The chemical structural formula of the N-alkyl aza-silacyclopentane is as follows:

wherein R1 can be methyl, ethyl, propyl, etc., and R2 can be alkyl, alkenyl, phenyl, etc.

The present invention will be described in further detail with reference to examples.

Example 1:

putting 100g of n-butylaminopropyltrimethoxysilane and 1g of sodium methoxide into a reaction vessel, starting stirring, and carrying out total reflux reaction by keeping the negative pressure of-0.095 MPa and the temperature of the reaction vessel at 130-150 ℃;

after reacting for 3-5 h, 85.1g of N-N-butyl-aza-2, 2-dimethoxy silacyclopentane can be obtained after the top temperature tends to be stable.

Example 2:

putting 100g of methacrylic aminopropyl trimethoxysilane and 2g of sodium amide into a reaction vessel, starting stirring, keeping the negative pressure of a reaction system at-0.095 MPa, and keeping the temperature of the reaction vessel at 130-150 ℃ for full reflux reaction;

after reacting for 3-5 h, obtaining 86.2g of 1, 1-dimethoxy-2-methylpropene-2-aza-1-silacyclopentane after the top temperature tends to be stable.

Example 3:

100g of aminoethylaminopropyltrimethoxysilane and 3g of magnesium amide are put into a reaction vessel, stirring is started, a reaction system keeps negative pressure of-0.095 MPa, and the temperature of the reaction vessel keeps 130-150 ℃ for full reflux reaction;

after reacting for 3-5 h, when the top temperature tends to be stable, 88.8g of N-aminoethyl-aza-2, 2-dimethoxysilacyclopentane can be obtained.

Comparative example 1:

methacrylic aminopropyl trimethoxysilane and hexamethyldisilazane are taken as raw materials, n-butyl aminopropyl trimethoxysilane, hexamethyldisilazane and a catalyst are put into a reaction vessel together, and heating reaction is carried out to obtain the final product. The final product was 1, 1-dimethoxy-2-methylpropene-2-aza-1-silacyclopentane, yield 75%.

The defects are as follows: the reaction process generates ammonia and trimethyl methoxy silane as side products, the recovery of the side products is considered in the whole reaction, and the price of the raw material hexamethyldisilazane is very high.

The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.

Claims

1. A synthetic method of N-alkyl aza-silacyclopentane is characterized by comprising the following steps:

2. The method of claim 1, wherein: the amino trialkoxy silane is silane containing amino and trialkoxy, and is one or more of n-butyl aminopropyl trimethoxy silane, methacrylic aminopropyl trimethoxy silane and aminoethyl aminopropyl trimethoxy silane.

3. The method of claim 1, wherein:

putting 100 parts by mass of amino trialkoxysilane and 1-3 parts by mass of catalyst into a reaction container, starting stirring, and keeping a reaction system at a negative pressure and the temperature of the reaction container at 130-150 ℃ for full reflux reaction;

4. The method of claim 1, wherein: the reaction vessel adopts a three-mouth flask and is provided with a packing column and a rectifying head.

5. The method of claim 1, wherein: the catalyst is a strong basic catalyst.

6. The method of claim 1, wherein: the catalyst is one of sodium methoxide, potassium methoxide, magnesium methoxide, sodium amide, potassium amide and magnesium amide.

7. The method of claim 1, wherein: when in reaction, the total reflux reaction is carried out under the negative pressure of less than-0.095 MPa.

8. An N-alkyl azasilacyclopentane characterized by: the raw material formula of the N-alkyl aza-silacyclopentane comprises the following components in parts by mass:

100 parts by mass of an aminotrialkoxysilane;

1-3 parts by mass of a strong basic catalyst.

9. The N-alkyl azasilacyclopentane of claim 8, wherein: the chemical structural formula of the N-alkyl aza-silacyclopentane is as follows:

wherein R1 is methyl, ethyl or propyl, and R2 is alkyl, alkenyl or phenyl.

10. The N-alkyl azasilacyclopentane of claim 8, wherein: the N-alkyl azasilacyclopentane is one or more of N-N-butyl-aza-2, 2-dimethoxy silacyclopentane, 1-dimethoxy-2-methylpropene-2-aza-1 silacyclopentane and N-aminoethyl-aza-2, 2-dimethoxy silacyclopentane.