Method for synthesizing bis(pinacolato)diboron

A technology of biboronic acid pinacol ester and chloroborane, which is applied in the field of organic synthesis and preparation chemistry, can solve the problems of unsuitability for large-scale production, high price of boron tribromide, unsafe operation, etc., and achieve stable conversion rate and purity , Facilitate solvent recovery and reduce loss

Active Publication Date: 2012-08-01
ASYMCHEM LAB TIANJIN +4
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Problems solved by technology

[0004] The first method is to prepare boron tribromide, dimethylamine and pinacol as starting materials through substitution, coupling and esterification (Journal of the American Chemical Society, vol.82.1960.6242-6245), in which tribromide The price of boron compound is relatively expensive, resulting in high cost of raw materials, which is not suitable for large-scale production;
[0005] The second method is to use boron trichloride, dimethylamine and pinacol as raw materials, through substitution, substitution, coupling and esterification (Gmelin Handbook, B: B-Verb.4), but the process can only be enlarged to Dozens of grams, and the operation is extremely unsafe, not suitable for mass production

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  • Method for synthesizing bis(pinacolato)diboron

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Experimental program
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Embodiment 1

[0026] Embodiment 1: a kind of synthetic method of biboronic acid pinacol ester is characterized in that concrete steps are as follows:

[0027] (1) Triamino substitution: Add 200kg (444.4mol, 1.0eq) of the main raw material 10% dimethylamine in n-hexane (14mL / g) to a 500L reactor, and add 10% trichloride dropwise at -20±2°C Boron chloride n-hexane (7mL / g) solution 104.2kg (88.9mol, 0.2eq), after dropping, the system was warmed up to 5 ± 2°C, and kept warm until the end of the NMR detection reaction; after the reaction, add 26kg of n-hexane ( 2mL / g), stirring, and centrifuging, the obtained filtrate is 306kg (9.5kg, 66.6mol) of n-hexane solution of tris(dimethylamino)borane, the yield is 90%, and the next step is to be cast;

[0028] (2) Diamino substitution: 306 kg (9.5 kg, 66.6 mol) of the n-hexane solution of tris(dimethylamino) borane prepared in step (1) was added to a 500L reactor, and added dropwise at -20±2°C 10% boron trichloride in n-hexane (9mL / g) solution 62.5kg (...

Embodiment 2

[0032] (1) Triamino substitution: Add 200kg (1111.1mol, 1.0eq) of 25% dimethylamine in n-heptane (4mL / g) as the main raw material to a 500L reactor, and add 25% Tris Boron chloride in n-heptane (2mL / g) solution 88.6kg (188.9mol, 0.17eq), after dropping, the system was heated up to 15±2°C, and kept warm until the reaction was detected by NMR; after the reaction, add n-heptane to the system Alkane 34kg (1mL / g), stirred, centrifuged, the obtained filtrate is 274kg (26.5kg, 185.2mol) of n-heptane solution of tris(dimethylamino)borane, the yield is 100%, and the next step is to be cast;

[0033] (2) Diamino substitution: Add 274kg (26.5kg, 185.2mol) of the n-heptane solution of tris(dimethylamino)borane prepared in step (1) to a 500L reactor, and drop it at -5±2°C Add 43.4kg (92.6mol, 0.5eq) of n-heptane (2mL / g) solution of 25% boron trichloride, after dropping, the system is warmed up to 15±2°C, and kept warm until the NMR detection reaction ends; Diatomaceous earth 13.3kg (0.5g / ...

Embodiment 3

[0037] (1) Triamino substitution: 200kg (1666.7mol, 1.0eq) solution of 45% dimethylamine in cyclohexane (2mL / g) as the main raw material was added to a 1000L reactor, and 45% trichloride was added dropwise at 0±2°C Boron compound cyclohexane (1mL / g) solution 106.5kg (500.0mol, 0.3eq), after dropping, the temperature of the system was raised to 25±2°C, and the temperature was kept until the end of the NMR detection reaction; after the reaction was completed, cyclohexane was added to the system 273kg (5mL / g), stirred and centrifuged, the obtained filtrate is 553.3kg (37.7kg, 263.9mol) of cyclohexane solution of tris(dimethylamino)borane, the yield is 95%, and the next step is to be cast;

[0038] (2) Diamino substitution: Add 553.3kg (37.7kg, 263.9mol) of the cyclohexane solution of tris(dimethylamino)borane prepared in step (1) to a 1000L reactor, and drop it at 0±2°C Add 68.7kg (263.9mol, 1.0eq) of 45% boron trichloride cyclohexane (1mL / g) solution, after dropping, the system ...

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Abstract

The invention relates to a method for synthesizing bis(pinacolato)diboron. In the method, commercial boron trichloride, dimethylamine and pinacol in the market are used as starting raw materials, and two-step substitution, coupling and esterification are performed to synthesize bis(pinacolato)diboron, and the product obtained in each step is continuously fed to next step in a solution state, so that the operation is simplified and the loss is reduced. According to the synthesis method, the adopted raw materials are inexpensive and easily available, the chemical reaction conditions are mild, and the conversion rate, yield and purity are very high. The synthesis method can be amplified to near kintal scale, thereby providing a feasible synthesis method for large-scale production of bis(pinacolato)diboron.

Description

(1) Technical field: [0001] The invention relates to the field of organic synthesis and preparative chemistry, in particular to a method for synthesizing biboronic acid pinacol ester. (2) Background technology [0002] The Suzuki reaction of aryl boronic acid and aryl halide under the action of metal palladium complex has been widely used in aralkylation reaction, but due to the hydrogen bond association between boronic acid group and boronic acid group, boronic acid group and hydroxyl group , the product purity is very low. Recent studies have shown that borate esters (such as pinacol esters) can also be directly used in the Suzuki reaction. In the Suzuki reaction, pinacol ester has the advantages of high reaction selectivity, mild conditions, and high yield. For some compounds whose substrates are unstable or need to improve reaction selectivity, it is better to react with pinacol ester and aryl halide. A great choice. The most commonly used method for the synthesis of ...

Claims

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Application Information

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IPC IPC(8): C07F5/04
Inventor 洪浩韦建丰惜春
Owner ASYMCHEM LAB TIANJIN
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