RU2260594C2 - Method for preparing organochlorogermanates - Google Patents

Abstract

FIELD: chemistry of organoelemental compounds, chemical technology.

SUBSTANCE: invention describes a method for preparing organochlorogermanates of the general formula: R_nGeCl_4-n wherein n = 2, 3; R means aromatic radical C₆H₅, ClC₆H₄, MeC₆H₄, SC₄H₃. Method involves interaction of organochlorosilane with germanium tetrachloride in the presence of Lewis acid as a catalyst - aluminum chloride at heating. Method involves using organochlorosilanes of the general formula: R_nMe_mSiCl_4-(n+m) wherein R means C₆H₅, ClC₆H₄, MeC₆H₄, SC₄H₃; n = 1-4; m = 0-2; the mole ratio R_nMe_mSiCl_4-(n+m) : GeCl₄ = (1.5-4):1, at temperature 50-130°C, and in the amount of catalyst 0.05-0.3 mole per 1 mole of organochlorosilane. Invention provides preparing organochlorogermanates from cheap and available organochlorosilanes and enhancing yield of the end product.

EFFECT: improved preparing method.

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Description

The invention relates to the field of chemistry of organoelement compounds, and specifically to a method for producing organochlorogermans of the general formula R _n GeCl _4-n (where n = 2,3: R = aromatic radical —C ₆ H ₅ , ClC ₆ H ₄ , MeC ₆ H ₄ , SC ₄ H ₃ ), which can be used to introduce diorganohermoxane units into various polymers or as terminal triorganohermyl groups, and also used as starting materials for preparative purposes.

The known method (I) for the production of diphenyldichloroherman consists in the bromination of tetraphenylgerman in carbon tetrachloride, the subsequent hydrolysis of the resulting diphenyldibromo-german with a mixture of alcohol and concentrated ammonium hydroxide, the subsequent processing of the polydiphenyl-germoxide formed with concentrated hydrochloric acid, and the subsequent C. brown phenyl-anne extraction. // J. Amer. Chem. Soc. - 1930. - V. 52, No. 9. - P.3690]. The yield of diphenyldichlorogerman is 40-60%.

The disadvantages of this method include: the need to use hard-to-reach tetraphenylgerman as the starting reagent, multistage processes, the use of solvents, and low yields of the target product.

Closer to the achieved results is the method (II) for the production of diphenyldichlorogerman by reacting tetraphenylgerman with germanium tetrachloride (in the ratio 1.1: 1) in the presence of aluminum chloride as a catalyst at an elevated temperature (120 ° C) [F. Rijkens, GJMVan derKerk // Recueil trav. chim. - 1964. - V. 83. - P. 723]. The yield of diphenyldichlorogerman is 70 ÷ 80%. Triphenylchlororgerman is prepared in a similar manner by increasing the ratio of Ph ₄ Ge: Cl ₄ Ge to 3: 1 [F. Rijkens, GJM Van der Kerk // Recueil trav. chim. -1964. -V. 83. -P. 723]. The yield of triphenylchlororgerman is 80%.

The disadvantages of this method also include the use of inaccessible tetraphenylgerman, which requires its preliminary synthesis and isolation, and, consequently, the additional expense of expensive germanium compounds.

Closest to the claimed invention in terms of features is a method (III) for the production of aryl trichlorogermans, which involves the interaction of aryl trichlorosilane [E.A. Chernyshev, M.E. Kurek, A.N. Polivanov; author testimonial. No. 316693, bull. fig. No. 30, 1971] or methyl aryl dichlorosilane [E.A. Chernyshev, M.E. Kurek, G.V. Motsarev and others; author testimonial. No. 445671, bull. fig. No. 37, 1974] with germanium tetrachloride in the presence of aluminum chloride at a temperature of 80-100 ° C at a ratio of arylchlorosilane: GeCl ₄ = 1 ÷ 1.

However, using this method, it is possible to obtain only aryl trichlorogermans, i.e., trifunctional derivatives, and not di- and monofunctional germanium monomers, which, in terms of practical applicability, serve completely different purposes (as indicated above, for introducing diorgano-germoxane units into various polymers or as terminal triorganohermyl groups).

The technical result of the present invention is to simplify the process of obtaining diorganodichloro and triorganochlorogermans and increase the yield of target products.

This technical result is achieved by the fact that as starting reagents take organomethylchlorosilanes of the general formula R _n Me _m SiCl _{4- (n + m)} , where R = С ₆ Н ₅ , ClC ₆ H ₄ , МеС ₆ H ₄ , SC ₄ Н ₃ ; n = 1 ÷ 4; m = 0 ÷ 2 and the process is carried out at a molar ratio of R _n Me _m SiCl _{4- (n + m)} : GeCl ₄ = 1.5 ÷ 4: 1, at a temperature of 50 ÷ 130 ° C, in the presence of a Lewis acid chloride catalyst aluminum in an amount of 0.05 ÷ 0.3 mol per 1 mol of organochlorosilane. With an increase in the total number of organic radicals in the molecule of the initial organomethylchlorosilane, as well as in the presence of thienyl radicals in it, the synthesis temperature and the amount of catalyst used decrease. The yield of target products 72 ÷ 90%.

Example 1. In a round bottom flask equipped with a stirrer, a thermometer and a reflux condenser, 93.3 g (0.5 mol) of phenylmethyldichlorosilane, 42.9 g (0.2 mol) of germanium tetrachloride and 20 g (0.15 mol) of aluminum chloride were placed. Then the reaction mixture is heated and kept under stirring at a temperature of 110 ÷ 130 ° C for 4-5 hours. 23.0 g (0.15 mol) of POCl _{3 was} added to the mixture and the resulting complex was filtered. The filtrate is distilled off and 52.3 g (88%) of diphenyldichloroherman are isolated, i.e., bp. 128-130 ° С / 1 mmHg, n _D ²⁰ = 1.5985.

Example 2. Analogously to example 1, a mixture of 177.1 g (0.7 mol) of diphenyldichlorosilane 42.9 g (0.2 mol) of germanium tetrachloride and 23.2 g (0.17 mol) of aluminum chloride is kept under stirring at a temperature of 110 ÷ 120 ° C for 5-6 hours. Then, 26.2 g (0.17 mol) of POCl _{3 was} added to the reaction mixture and the resulting complex was filtered off. The filtrate was distilled, the product was recrystallized from hexane, and 58.3 g (86%) of triphenylchlororgerman were isolated, i.e. 114-115 ° C.

Example 3. Analogously to example 1, a mixture of 100.8 g (0.3 mol) of tetraphenylsilane, 42.9 g (0.2 mol) of germanium tetrachloride and 8.0 g (0.06 mol) of aluminum chloride is kept under stirring at a temperature of 90 ÷ 100 ° C for 4-5 hours. Then, 9.2 g (0.06 mol) of POCl _{3 was} added to the reaction mixture, and the resulting complex was filtered. The filtrate is distilled and 53.5 g (90%) of diphenyldichloroherman are isolated, i.e., bp. 128-130 ° С / 1 mmHg, n _D ²⁰ = 1.5985.

Example 4. Analogously to example 1, 98.5 g (0.5 mol) of thienylmethyldichlorosilane, 42.9 g (0.2 mol) of germanium tetrachloride and 6.7 g (0.05 mol) of aluminum chloride are mixed. Then the reaction mixture is heated and kept under stirring at a temperature of 50 ÷ 70 ° C for 2-3 hours. To the mixture was added 7.7 g (0.05 mol) of POCl ₃ and the resulting complex was filtered off. The filtrate is distilled and 51.9 g (87%) of dithienediichlororgerman, i.e., boiling water, 152/2/2 mm Hg are isolated. Art. n _D ²⁰ = 1.6075.

Example 5. Analogously to example 1, a mixture of 168 g (0.5 mol) of tetraphenylsilane 42.9 g (0.2 mol) of germanium tetrachloride and 13.3 g (0.1 mol) of aluminum chloride is kept under stirring at a temperature of 90-100 ° C for 5-6 hours. Then, 15.4 g (0.1 mol) of POCl _{3 was} added to the reaction mixture, and the resulting complex was filtered off. The filtrate was distilled, the product was recrystallized from hexane, and 57.6 g (85%) of triphenylchlororgerman were isolated, i.e. 114-115 ° C.

Thus, the proposed method allows to simplify the process of obtaining diorganodichloro and triorganochlorogermans and increase the yields of target products.

Claims (1)

A method of obtaining organochlorogermans of the General formula R _n GeCl _4-n , where n = 2,3; where R = aromatic radical C ₆ H ₅ , ClC ₆ H ₄ , MeC ₆ H ₄ , SC ₄ H ₃ , by reacting organochlorosilane with germanium tetrachloride in the presence of a Lewis acid catalyst - aluminum chloride when heated, characterized in that organochlorosilanes of the general formula are used R _n Me _m SiCl _{4- (n + m)} , where R = C ₆ H ₅ , ClC ₆ H ₄ , MeC ₆ H ₄ , SC ₄ H ₃ , n = 1-4, m = 0-2, the molar ratio of R _n Me _m SiCl _{4- (n + m)} : GeCl ₄ = 1.5 ÷ 4: 1, at a temperature of 50-130 ° C, the amount of catalyst is 0.05-0.3 mol per 1 mol of organochlorosilane.