RU2496781C1 - Method of producing 1,1'-bis(dimethyl alkoxysilyl)-ferrocenes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing heteroannular ferrocene derivatives. Disclosed is a method of producing 1,1'-bis(dimethyl alkoxysilyl)ferrocenes by reacting heteroannular 1,1'-dilithium ferrocene with dimethyl alkoxychlorosilanes in the medium of inert solvents.

EFFECT: fewer steps and high selectivity of the method.

2 cl, 1 tbl, 5 ex

Description

The invention relates to the field of heteroannular disubstituted derivatives of ferrocene, which are widely used as high-temperature stabilizers of polymeric materials, additives to motor oils and diesel fuels, and solid rocket fuel combustion catalysts.

The use of derivatives instead of ferrocene itself is intended to remove the limitations of its use due to such negative properties of ferrocene as its relatively high volatility, low solubility, and poor compatibility with polymer compositions.

Organosilyl derivatives of ferrocene, and especially those containing functional alkoxy groups at the silicon atom, are widely distributed. These are, as a rule, liquid low-volatility products having low glass transition temperatures, which is important for use in polymer binder formulations. In addition, alkoxysilyl ferrocenes also exhibit plasticizing properties.

General formula:

where R, R 'is alkyl, aryl, n = 0-2.

A known method of producing these compounds by reaction of a cyclopentadienylsilyl derivative containing the corresponding functional group with Grignard reagent, with an alkyl (aryl) lithium compound or with dispersed metallic sodium, followed by exposure to the organometallic compound with ferric chloride [R.L. Schaaf et al. J Org. Chem. 26, 1790-1795 (1961); Auto St USSR 280478 (1970) B.K. Kabanov et al. ZhOKh, 1972, 42, 1749-1752; IN AND. Run et al. Chem. prom 1995, No. 11, 666-671].

The products obtained by this method are heteroannular disubstituted silyl ferrocenes. As a modified version of this method, it is proposed that alkoxysilyl ferrocenes be produced by alcoholysis of the corresponding disubstituted silyl ferrocenes containing a nitrogen atom at a silicon atom [Auth. 280,479 (1970); IN AND. Sidnev et al.: Navy. 1971 (A) XIII, No. 11, 2526-2531].

In this case, the starting aminosilylferrocene is also obtained from the corresponding aminosilylcyclopentadienes according to the same scheme as alkoxysilylferrocenes.

Thus, the known methods for the preparation of heteroannular disubstituted alkyl alkoxysilyl ferrocenes are multistage, are accompanied by adverse reactions proceeding along functional alkoxyl groups, which leads to a decrease in the yield of the target product.

The purpose of the invention is to reduce the number of stages, increase the yield of target products. Bis-1,1 '(dimethylalkoxysilyl) ferrocenes were identified as objects of the invention.

The goal is achieved by using as the initial components of the reaction: heteroannular 1,1'-dilithioferrocene and dimethylalkoxychlorosilanes.

For the prototype, we adopted the method described in the copyright certificate 280478 (1970), where cyclopentadienylalkyl (alkoxy) silanes are used as starting materials, which are reacted with an alkali metal followed by treatment with ferric chloride.

It is known [Marr G., White T. M., J. Chem. Soc. S.1970, 1789] that dilithium ferrocene interacts with trimethylchlorosilane to form 1,1'-bis (trimethylsilyl) ferrocene in high yield.

In the publication [V.I. Run et al. Chem. Prom. 1995, No. 11, 666-671], it is noted that the restrictions on the use of this method for the preparation of organosilyl ferrocenes containing functional reactive alkoxyl groups at the silicon atom are associated with the fact that metalizing agents can react with alkyl alkoxychlorosilanes not only through the silicon bond -chloro also in the reaction alkoxy group at the silicon atom.

Nevertheless, we were able to show that, under certain conditions, dimethylalkoxychlorosilanes interact with 1,1'-dilithyferrocene to form 1,1'-bis (dimethylalkoxysilyl) ferrocenes in high yield.

The table shows the yields of 1,1'-bis (dimethylalkoxysilyl) ferrocene according to the prototype and the claimed method:

No. p / p Compound Prototype output The output of the claimed method one. 1,1'-bis (dimethylethoxysilyl) ferrocene 70 71 2. 1,1'-bis (dimethylbutoxysilyl) ferrocene - 74 3. 1,1'-bis (dimethyloctoxysilyl) ferrocene 16 81

Compared with the prototype, the proposed method eliminates the dangerous stage of metallization of cyclopentadiene with alkali metals, as well as the need to obtain and isolation of intermediate products. A significant advantage of the proposed method is the use of ferrocene as the main raw material, an affordable and cheap product, instead of the unstable compound cyclopentadiene.

In the proposed method, the synthesis of bis- (dimethylalkoxysilyl) ferrocene is carried out in one reactor. At the first stage, in an atmosphere of inert gas (nitrogen), a previously prepared suspension of dilithium ferrocene in a solvent is charged. Then, with stirring, maintaining a temperature of 0-70 ° C, a dosage of the corresponding dimethylalkoxychlorosilane is carried out. After dosing, stirring is continued for another 6-7 hours. Then the reaction mass is separated from lithium chloride, the solvent is distilled off at atmospheric pressure and the residue is distilled in vacuum.

The resulting 1,1'-bis (dimethylalkoxysilyl) ferrocenes are colored, high-boiling thermostable liquids, soluble in organic solvents.

Example 1. Obtaining 1,1'-bis [dimethyl (2-ethylhexoxy) silyl] ferrocene.

The reaction is carried out in a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and an inert gas supply device. In a reactor previously purged with nitrogen, 500 ml of a suspension of 1,1'-dilithyferrocene in heptane are loaded (the content of dilithium ferrocene is 26 g, 0.13 mol). Then the contents of the reactor are cooled and at a temperature of 0 (+ 25 ° C, a dosage of 68 g (98%, 0.30 mol) of dimethyl (2-ethylhexoxy) chlorosilane is conducted. After dosing, the reaction mass is kept under stirring for 7 hours, lithium chloride is separated The solvent is distilled off at atmospheric pressure, the residue is distilled in vacuo. The boiling fraction is collected at a temperature of 200-220 ° C and a vacuum of 1-1.5 mm Hg.

1,5060, $${\text{d}}_{\text{4}}^{\text{20}}$$

1,0300 г/см³.The yield of 1,1'-bis [dimethyl (2-ethylhexoxy) silyl] ferrocene was 57.5 g (81%), $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5060, $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.0300 g / cm ³ .

Found,%: Fe 10.15; Calculated,%: Fe 10.03.

Literature data:

1,0411 г/см³; $${\text{n}}_{\text{D}}^{\text{20}}$$

1,5065; содержание Fe 9,68%.t _bales 150-160 ° C / 0.075 mm Hg; $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.0411 g / cm ³ ; $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5065; Fe content 9.68%.

Example 2. The synthesis is carried out analogously to example 1. As a solvent, the hexane fraction of petroleum ether of the following composition is used: hexane - 65%, isohexanes - 30%, pentane, heptane, octane - 5%. The dosage of dimethyl (2-ethylhexoxy) chlorosilane is carried out at a temperature not exceeding 75 ° C. The reaction mass is kept for 6 hours at room temperature.

Isolation of 1,1'-bis [dimethyl (2-ethylhexoxy) silyl] ferrocene is carried out analogously to example 1:

1.5068. $${\text{d}}_{\text{4}}^{\text{20}}$$

1,0344 г/см³.Received 44.3 g (61% of theory), $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5068. $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.0344 g / cm ³ .

Found,%: Fe 10.15;

Calculated,%: Fe 10.03.

Example 3. The synthesis is carried out analogously to example 1. As a dililiter ferrocene solvent, tetrahydrofuran is used.

1.5075. $${\text{d}}_{\text{4}}^{\text{20}}$$

1,03050 г/см³.Received 50.1 g (70% of theory) of 1,1'-bis [dimethyl (2-ethylhexoxy) silyl] ferroc, $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5075. $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.03050 g / cm ³ .

Found,%: Fe 10.45;

Calculated,%: Fe 10.03.

Example 4. Obtaining 1,1'-bis (dimethylethoxysilyl) ferrocene.

The synthesis is carried out according to a similar procedure described in example 1. To a suspension of dilithium ferrocene in the hexane fraction of petroleum ether, maintaining the temperature no higher than 50 ° C, 38 g (0.27 mol, 98% by GLC) of dimethylethoxychlorosilane are added dropwise.

The result is 36.0 g of 1,1'-bis (dimethylethoxysilyl) ferrocene with a boiling point of 145-150 ° C at 1.5 mm Hg.

1.5120; $${\text{d}}_{\text{4}}^{\text{20}}$$

1,1268 г/см³.The yield was 71% of theory, $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5120; $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.1268 g / cm ³ .

Found,%: Fe 13.85;

Calculated,%: Fe 14.36.

1.5260; $${\text{d}}_{\text{4}}^{\text{20}}$$

1,1300 г/см³.Literature data: 108-110 ° C / 0.09 mmHg, $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5260; $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.1300 g / cm ³ .

Example 5. Obtaining 1,1'-bis (dimethylbutoxysilyl) ferrocene.

The synthesis is carried out similarly to the procedure described in example 1. The yield was 74%.

1.5105; $${\text{d}}_{\text{4}}^{\text{20}}$$

1,0780 г/см³.Boiling point 1,1'-bis (dimethylbutoxysilyl) ferrocene 180-190 ° C vacuum 1 mm Hg; $${\text{n}}_{\text{D}}^{\text{twenty}}$$

1.5105; $${\text{d}}_{\text{four}}^{\text{twenty}}$$

1.0780 g / cm ³ .

Found,%: Fe 12.51;

Calculated,%: Fe 12.55.

Claims (2)

1. The method of obtaining heteroannular disubstituted organosilyl ferrocenes containing functional alkoxy groups at the silicon atom, characterized in that the dilithoferrocene is reacted with dimethylalkoxychlorosilanes in an inert solvent, followed by isolation of the target product by known methods. 2. The method according to claim 1, characterized in that low-boiling hydrocarbons, mixtures of hydrocarbon solvents, tetrahydrofuran are used as solvent.