Preparation method of bis(pinacolato)diboron

Abstract

The invention discloses a preparation method of bis(pinacolato)diboron. The preparation method comprises the following steps of: S1, synthesis of n-hexane: S11, taking a reactive material, namely a methyl-rich pentane; S12, taking a catalyst, namely anhydrous aluminum halide; S13, adding the methyl-rich pentane and the anhydrous aluminum halide with the weight ratio of 1-10 into a reactor at 45-105 DEG C, and carrying out full stirring and reaction to obtain the n-hexane; S2, purification of boron trichloride: S21, a decomposition section; and S22, a rectification section; S3, pinacol dehydration to obtain a pinacol product; S4, preparation of bis(pinacolato)diboron; and S5, material recovery: rectifying filtrate in the step S4 and then recovering toluene and 1,2-dichloroethane. Accordingto the preparation method, the n-hexane is synthesized before preparation of the bis(pinacolato)diboron; through use of the self-produced n-hexane, the preparation cost of the bis(pinacolato)diboron is reduced, and meanwhile, continuous supply of the n-hexane in production is achieved, so that the production efficiency is conveniently improved.

Description

technical field [0001] The invention belongs to the technical field of double pinacol borate preparation, and in particular relates to a preparation method of double pinacol borate. Background technique [0002] Double pinacol borate, also known as pinacol borate, is a pharmaceutical intermediate with a molecular formula of C12H24B2O4. Bispinacol borates are gaining increasing importance in organic synthesis. [0003] Can refer to the Chinese patent that authorization announcement number is CN107573369A, and it discloses a kind of preparation method of alkyl borate, comprises the following steps: with the alkyl p-toluenesulfonate shown in formula Ⅰ-a and diboronic acid pinacol The ester is used as a raw material, and under the action of a silver catalyst and a base, the reaction is carried out to obtain the alkyl borate ester represented by formula I. [0004] The above-mentioned preparation method of this alkyl borate directly adopts commercially available silver salt as ...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned preparation method of this alkyl borate directly adopts commercially available silver salt as a catalyst to participate in the reaction, the reaction system and feeding method are simple, and no ligand needs to be added; but the preparation of the existing double pinacol borate The method still has some disadvantages, such as: one, the n-hexane used in the preparation of double pinacol borate generally adopts the mode of purchase, the preparation cost is higher, and it is not conducive to the continuous supply of n-hexane, when n-hexane is insufficient , easily affect production efficiency; Two, the purity of boron trichloride and pinacol used when preparing double pinacol borate is not high, and it is not convenient to process the purity of boron trichloride and pinacol, Affect the quality of the prepared double pinacol borate

Images