Preparation of tri(dimethylin) borane

Abstract

The invention relates to a method for preparing a compound, in particular to a method for preparing tris(dimethylamino)borane. The method directly uses a target product, namely tris(dimethylamino)boron, with the content over 90 percent as a solvent, introduces raw materials, namely boron trichloride and a dimethylamine solution into the solvent to react under a stirring condition so as to preparethe tris(dimethylamino)borane. The method is safe and environment friendly, saves the solvent, and reduces cost. When a reacting condition is selected properly, the tris(dimethylamino)borane can be prepared with quite high yield, and side products can be smoothly removed in a filtering process, so that purer tris(dimethylamino)borane can be obtained. The side products can be used as raw materialsfor recycling, or be used as products for sale after proper treatment, and are friendly to environment. The method has the advantages of mild and smooth reaction performance, controllable reaction velocity and reaction temperature through controlling aeration rate, and safety. After the reaction is finished, excess dimethylamine can be recycled.

Description

Technical field: [0001] The present invention relates to the preparation method of compound, especially the preparation method of tris(dimethylamino)borane. Background technique: [0002] For industrial production, the reaction of gas and gas is quite difficult. The preparation of tris(dimethylamino) boron is the reaction of gas and gas. The usual method is to first freeze and dissolve the raw material dimethylamine in a solvent, and stir at low temperature. Boron trichloride is passed into the reactor, and then rectified to obtain high-purity tris(dimethylamino)boron product. The choice of solvent type is a very critical issue. It is necessary to consider a series of physical properties such as the freezing point, boiling point, and toxicity of the solvent, as well as the influence of the solvent on the reaction selectivity and stability, and the solubility of the reactants and products. , and the impact of solvents on cost. Therefore, in actual operation, the choice of s...

AI Technical Summary

Problems solved by technology

In addition, due to the particularity of the reaction, it is necessary to consider the amount of solvent used. If the amount is small, it will be difficult to stir and the yield will decrease.

If the amount is too large, a large amount of waste liquid will be generated, which is not conducive to environmental protection and will increase the cost

In "Organic Synthesis Cumulative Volume 10", on page 115, the method for preparing tris(dimethylamino)borane with pentane as a solvent is mentioned, but in actual production, the reaction solvent n-pentane is a very dangerous chemical raw material. The boiling point and flash point are very low, the volatility is good, and there is a great potential safety hazard

In the invention patent application with the application number 200710010757.9, the method of using highly salt-soluble solvents such as ionic liquids, sulfolane or N-methylimidazole as reaction solvents is mentioned. Although the above-mentioned solvents can be effectively recovered, the price is still relatively expensive. It is conducive to large-scale industrial production, and the distillation method is used to purify the product during the production process. During the purification process, some products will be lost and the yield will not be optimal.

In the invention patent application with the application number 200710010756.4, the method of using toluene as a solvent is also mentioned, and there is also the problem that the recovery and yield are not optimal.