Method for synthesizing bromotrimethylsilane

Abstract

The invention discloses a method for synthesizing bromotrimethylsilane, and relates to a synthetic production technology for a chemical product. The method comprises the following steps of: under oxygen-free conditions, stirring in a reaction kettle in which phosphorus tribromide and silyl ether are sequentially added, raising the temperature to 1005 DEG C, keeping the temperature, performing reflux reaction for 60.5 hours, rectifying under normal pressure to obtain the bromotrimethylsilane, and stopping to receive a finished product of the bromotrimethylsilane when the temperature in the kettle is raised to 135 DEG C. By the method, a silyl ether-phosphorus tribromide method is improved and innovated, side reactions are avoided, the obtained product has purity, and the finished product of the bromotrimethylsilane which has the content of about 99 percent can be obtained; and the stirring at normal temperature is changed into high-temperature reflux, so that the reaction time is greatly shortened.

Description

technical field [0001] The invention relates to the technical field of production of chemical products, in particular to a method for chemically synthesizing bromotrimethylsilane. Background technique [0002] Trimethylbromosilane is a new type of organosilicon synthesis reagent, which is mainly used in the synthesis of antiviral drugs. PMPA) is an essential raw material. [0003] There are several synthetic methods reported in the literature as follows: [0004] 1. Hexamethyldisilane method: Me 3 SiSiMe 3 +Br 2 → 2Me 3 SiBr, the product yield of this method is high, but the reaction is violent and difficult to control, and it is prone to explosion. In addition, the raw material hexamethyldisilane is expensive, and it has gradually lost the significance of industrial production. [0005] 2. Silicone ether—aluminum powder method: Me 3 SiOSiMe 3 +Br 2 + 2 / 3 Al → 2Me 3 SiBr + 1 / 3 Al 2 o 3 , the reaction temperature of this method is high, there are many by-pr...

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Problems solved by technology

[0004] 1. Hexamethyldisilane method: Me 3 SiSiMe 3 +Br 2 → 2Me 3 SiBr, the product yield of this method is high, but the reaction is violent and difficult to control, and it is prone to explosion. In addition, the raw material hexamethyldisilane is expensive, and it has gradually lost the significance of industrial production

[0005] 2. Silicone ether—aluminum powder method: Me 3 SiOSiMe 3 +Br 2 + 2 / 3 Al → 2Me 3 SiBr + 1 / 3 Al 2 o 3 , the reaction temperature of this method is high, there are many by-products and it will solidify at about 120°C, which is difficult to handle. The product contains about 15% of dimethyldibromosilane, which is difficult to separate and affects the use of the product

[0006] 3. Silicon ether—triphenylphosphine method: Me 3 SiOSiMe 3 +Br 2 + Ph 3 P → 2Me 3 SiBr + Ph 3 PO, the raw material triphenylphosphine used in this method is expensive, and the by-product triphenoxyphosphine is difficult to handle, which is not conducive to industrial production

[0007] 4. Phenyltrimethylsilane method: PhSiMe 3 +Br 2 → Me 3 SiBr + PhBr, because a small amount of hydrogen bromide produced in the reaction will cause phenyltrimethylsilane to decompose into benzene, resulting in the final product of this method containing about 5% benzene, and the boiling point of benzene and trimethylbromosilane is very close, Inseparable, affecting product use

[0008] 5. Silicon ether - phosphorus tribromide method: Me 3 SiOSiMe 3 + PBr 3 → Me 3 SiBr, this method needs to use iron trichloride as catalyzer, and because there is following side reaction: Me 3 SiBr + FeCl 3 → Me 3 SiCl + FeBr 3 , resulting in the product containing about 3% trimethylchlorosilane impurity, which affects the use of the product, and there are many by-products, which are difficult to handle