CS267800B1 - Process for the preparation of trisdietylaminosiliciumchloride - Google Patents

Abstract

The solution and concerns the method of synthesis trisdiethylaminosilioium chloride in the yard reaction steps. In the first stage of the reaction quench the silica with β with diethylamine in the presence of ether to form a mixture Contains diethylaminotriohlérsilium, biediotylaminodiohlérsilíoium a according to the rheok conditions, even a small amount triadiotinylminosilium chloride, wherein, after removal of the precipitate, the mixture is mixed in the second stage he reacted in the presence metal sodium. with excess diethylamine dissolved in the absence. After removing diethylaminohydrochloride a the rest of the metal sodium by filtration and excess diethyl amine is obtained by distillation a crude product containing at least 95. \ t the mass of trisdiethylaminosilium chloride, who may have cleansed the descendant des tiláoiou. under reduced pressure. The compound obtained It is suitable as an adjuvant preparation of silicon nitride.

Description

The solution relates to a process for the preparation of trisdiethylamino-bililor chloride in two steps. This compound is useful as an excipient in the production of chromium nitride.

The synthesis of dialkylaminosilanes is described by Anderson (Am, Chom, Sec., 1952, s, la2l). Another route for the preparation of dialkylamino derivatives Ti, Zr and Ta is described by Bradley and Thomas / Proc. Chem. Soc, 1959, p. 225), by reacting the corresponding transition metal chlorides with lithium dioxides. The disadvantage of these processes is that η 1mi failed to prepare ethyl derivatives in the required yields. These disadvantages are eliminated by the process for the preparation of the trisdiethylaminosilicon chloride of the present invention, which is essentially the reaction of silicon tetrachloride with diethylamine in two steps.

In the first reaction step, the redistilled silica is dissolved in freshly redistilled dried ether, preferably diethyl ether, to give a solution directly in the dried reaction vessel. The reaction vessel is placed in a cooling box and the temperature of the solution is kept below 0 ° C, preferably in the range of -20 to -40 ° C. The reaction vessel is equipped with a stirrer, the construction of which allows the isolation of the reaction medium from the surrounding atmosphere. The moving parts of the handle which come into contact with the reaction medium are covered with a layer of Teflon, thus ensuring the purity of the final product, in view of the possible contamination of the product with metals from the handle. Freshly dried diethylamine is metered into a cooled solution of silica in ether in small portions into a reaction vessel equipped with a high shear stirrer. During the dosing of diethylamine into the reaction medium, the stirrer is constantly operated. The addition of diethylamine gives the precipitate of diethylamino hydrochloride, which must be stirred in the reaction medium throughout the reaction. The nature of the reaction is exothermic, so diethylamine is metered in after cooling the reaction medium, preferably in the temperature range -20 to -10 ° C. After all of the diethylamine has been added, the reaction vessel is slowly warmed to ambient temperature with occasional stirring. Under the above reaction conditions, a mixture containing the active ingredients diethylaminotrichlorosilicon, bisdiethylaminodioblorosilicon and under the reaction conditions also forms trisdiethylaminosilicon chloride and under the reaction conditions also trisdiethylaminosilicon chloride and the by-product diethylaminohydrochloride is mixed with free of residues of active ingredients. The solvent is removed from the active ingredient mixture by distillation.

In the second step, the active ingredients from the first step are reacted with an excess of freshly redistilled diethylamine in the presence of sodium metal in the absence of solvent. Filtration of the diethylaminohydrochloride by-product also removes unreacted sodium residues and, after distilling off the excess diethylamine, gives the crude product trisdiethylaminosilium chloride, containing at least 95% by weight, which can be further purified by distillation under reduced pressure.

The advantages of said process for the synthesis of the stage of the present invention lie in the fact that the inclusion of both reaction steps shifts the equilibrium in the direction of the final product, thus ensuring higher conversion and the resulting crude product contains at least 95 .mu.l of the desired component.

Another advantage of said process for the synthesis of the stage of the present invention is that the second stage of the reaction is carried out without the use of a solvent at conventional laboratory temperatures of about + 20 ° C.

CS 267 800 Dl

The product formation fraction can be described by the equation;

_EXAMPLE month ₍₊ 6 / C ₂ H _5/2 n '

[/ ^C2 _H5 / ₂ N] ₃ of the sewing-U / C ₂ H _{5/2 NH2} ci

The power of triadiethylaminosilicon chloride is governed by the gradual substitution of chlorine in the reaction stage:

SiCl ₍₊ 2 / C ₂ II / NH ₂ ------------ / C _{2 »5/2} NSiCl ₃ + 2 / C ₂ H _5/2 NH - [/ c ₂ h _5/2 n] of the sewing _{2 2} + 2 / C ₂ h _5/2 nh -> / C ₂ h _{5/2 NSIC-3} / C ₂ h _5/2 NH ₂ C ----> [/ c ₂ h _5/2 n] ₂ + SiCl ₂ / C ₂ h _{5/2 NH2} ci

---> [/ C ₂ H _5/2 n] + S1C1 ₃ / C ₂ H _{5/2 NH2} ci

Table 1 includes experimental data on the synthesis of all three starting materials in the first reaction step.

Table 1:

syn t é za č. diotyl 1 yes Yes 3 yes 4 yes excess diethylamine over stoichiomotry (mass) 0 25 50 100 The title / C ₂ H _5/2 NSiCl (wt 50 25 5 feet [/ C ₂ H _5/2 SÍC1 NJ _{2 2} (w ¢) 50 75 90 80 pC ₂ H _5/2 N] ₃ SiCl (w £) 0 0 5 20 Data 0 of the final products from Table 1 as well as theirs representation in the samples were obtained by mass spectroscopy, In syntheses 1 to 4 / first stage of preparation / was used as a solvent for diotyl ether.

These syntheses differ in the amount of excess diethylamine used, which determines the incorporation of the synthesized substances in the final product. products.

In the second stage of the preparation, the reaction equilibrium is shifted so that the resulting product contains at least 95% by weight of trisdiethylaminosiliconurochloride.

The advantages of the process for the synthesis of tridiethylaminosiliconurochloride according to the invention can be documented by comparing Examples 1 and 2.

Example 1 (Synthesis No. 4)

20 g (0.1177 mol) of SiCl3 are added to 200 ml of solvent and the solution prepared is stirred and cooled, then 103.4 g (1.4135 mol) of diethylamine are gradually added with continuous stirring. After the addition of all the diethylamine, the reaction vessel was slowly warmed to ambient temperature. After filtering off the diethylaminohydrochloride and washing the filter cake with a pure solvent, a solution containing the active ingredients is obtained, from which the solvent has been removed by filtration. Yield: 26 g of product containing a trace / C ₂ H _5/2 NSiCl _3, 80 w £ [/ C ₂ H _5/2 N] ₂ SíC1 ₂ and 20 wt $ [/ C ₂ H _5/2 N] ₃ SÍC1.

CS 267 800 Bl

Example 2 (synthesis according to the invention)

The first stage of reaction represents any of the syntheses no. 1 to 4 of Table 1, preferably Synthesis 1 is used.

20 g (0.1177 mol) of SiCl3 are added to 200 ml of solvent and the solution prepared is stirred and cooled and 51.7 g (0.7068 mol) of diethylamine are gradually added with continuous stirring. After the addition of all the diethylamine, the reaction vessel is slowly warm to ambient temperature. After filtering off the diethylaminohydrochloride and washing the filter cake with a pure solvent, a solution containing the active ingredients is obtained, from which the solvent is removed by distillation. Yield: 22 g of product containing 50% wt / C ₂ H _5/2 NSiCl ₃ and 50 wt% [/ C ₂ H _5/2 N] ₂ SÍC1 _second

In the second stage, do we take the product from the first stage of the reaction and not react to it? in the presence of sodium metal with 100 ml of diethylamine (without solvent) after filtering off the resulting diethylaminohydrochloride and unreacted sodium and distilling off the excess diethylamine, the crude product is obtained 23 g of a liquid containing 95 wt. If higher purity is required, we redistill it under reduced pressure.

It follows from the above examples that in the reaction using a solvent e.g. (Example 1 Synthesis 4) At 100 excess diethylamine, equilibrium was stabilized with relatively low product conversion (20 wt%). While in the synthesis carried out in two steps (Example 2), according to the process of the present invention, a crude product containing 95% by weight of trisdiethylaminosilium chloride is obtained.

Claims (2)

OBJECT OF THE INVENTION 1. A process for preparing trisdietylaminosilíoiumchloridu £ / C ₂ H _3/2 SiCl NJ, characterized in that in a first step are reacted silicon tetrachloride SiCl ^ dry diethylamine in ether, preferably diethyl ether, at a temperature below 0 ° C, preferably -20 to -40 ° C, to give a mixture containing diethylaminotrichersiliconium, bisdiethylaminodiohydrosiliconium and optionally trisdiethylaminosilicon chloride, which removes the precipitate of diethylaminohydrochloride and then removes the solvent and in a second step the mixture is reacted. with an excess of dry diethylamine in the presence of sodium metal and the resulting product is freed from the precipitate of diethylaminohydrochloride and unreacted sodium and then the excess diethylamine is distilled off. 2. The process according to item 1, characterized in that the obtained crude product trisdiethylaminosilium chloride is purified by distillation under reduced pressure.