Preparation method of triphenyl borate
Through the further treatment of the heating response of the three (mimethyl amin amin amin amin amin amin amino) and the phenol and the further treatment of the micro vacuum conditions, there are many by -products, impurities, unsuitable products, and inadequate products in the preparation of the existing technologies. The problem of low income yields realizes the preparation of tritenopate boric acid with high purity and high income, which is suitable for industrialized production.
Patent Information
- Application Number
- CN202411442792.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2025-01-24
AI Technical Summary
The existing preparation methods for triphenylborate have problems such as many by-products, many impurities, difficult product purification, low yield, high equipment requirements and poor economicality.
The intermediate is obtained by reacting the heating response of the three (dimethyl amin amin amin amin amin amino) and the phenol. Then it further reacted under micro -vacuum conditions. Through purification and replacement steps, the high -purity tritenophenyl boric acid was finally obtained.
The high purity (more than 99.5%) and high yield of triphenylborate are achieved, which is suitable for industrial scale-up production.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of pharmaceutical intermediate synthesis, and particularly relates to a method for preparing triphenylborate. Background Art
[0002] Triphenylborate is an intermediate for preparing boron hydride compounds. It can be used to synthesize semiconductor boron diffusion sources, fire retardants, polymer additives or sterilants, flame retardants, special surfactants, and can also be used as a complexing agent for weak Lewis acids and nitrogen-containing compounds. It is widely used in Suzuki cross-coupling reactions, asymmetric synthesis of amino acids, amino compound catalysts, etc. Therefore, the application of triphenyl borate is wide, and its stable and high-quality triphenylborate preparation process is particularly important. At present, the methods of triphenylborate are roughly divided into the following three types:
[0003] The first method, as reported in the literature [Chemical Communications, 2005, 1426-1428], is to mix phenol and THF under argon protection and cool to 0°C, then drop borane dimethyl sulfide complex to react and obtain triphenyl borate. This reaction uses borane dimethyl sulfide complex, which has a strong odor and is highly toxic. It is not suitable for large-scale production. The reaction route is shown as follows:
[0004]
[0005] The second method, as reported in the literature [Russian Journal of Organic Chemistry, 2009, 45, 1772-1775 and European Journal of Inorganic Chemistry, 2006, 8, 1690-1697], uses boric acid and phenol in toluene or xylene to reflux and separate water to obtain the target compound. However, this method easily generates boric acid polymers and has many impurities. Triphenyl borate is a solid and is not easy to distill out, which makes it difficult to purify and thus reduces the yield. The reaction route is shown as follows:
[0006]
[0007] The third method, the literature [Journal of the Chemical Society, 1962, 1505-1507] reported that phenyl chlorosulfonate or phenyl chlorosulfinate was reacted with boron trichloride at -80°C to obtain the target compound. This method requires ultra-low temperature of -80°C and uses boron trichloride, which has high requirements for equipment and poor economic efficiency. The reaction route is shown as follows:
[0008] Summary of the invention
[0009] In order to solve the above problems and achieve the above invention objectives, the present invention provides a method for preparing triphenylborate. The core of the technical solution adopted by the preparation method is two steps: 1) tri(dimethylamino)borane and phenol are heated to react to obtain an intermediate; 2) the intermediate is heated to react under a slight vacuum to obtain triphenylborate. In the preparation method described in the present invention, the intermediate generated after the first step of phenol exchange is a triphenylborate-dimethylamine complex, and the complex is purified and heated, and dimethylamine can be removed under a slight vacuum condition. The purity of the triphenylborate product finally obtained can reach more than 99.5%, and the yield is improved compared with the literature, which is suitable for industrial scale-up production.
[0010] The preparation method of triphenyl borate of the present invention comprises the following steps:
[0011] Step 1: Mix phenol and an organic solvent, add tri(dimethylamino)borane solution dropwise, then slowly heat up to react and bring out dimethylamine, cool down and filter to obtain an intermediate;
[0012] Step 2: Mix the intermediate with an organic solvent, reflux under a slight vacuum to react and bring out dimethylamine, then cool and filter, evaporate the filtrate under reduced pressure to remove the solvent, add n-heptane to replace it, cool and crystallize and filter to obtain triphenylborate.
[0013] The reaction route is shown below:
[0014]
[0015] Furthermore, in the above technical solution, the organic solvent in the first step is selected from toluene, xylene or chlorobenzene.
[0016] Furthermore, in the above technical solution, the reaction temperature in the first step is selected from 40-90°C.
[0017] Furthermore, in the above technical solution, the molar ratio of tri(dimethylamino)borane to phenol in the first step is 1:3.0-3.5.
[0018] Furthermore, in the above technical solution, the organic solvent in the second step is selected from toluene or xylene.
[0019] Furthermore, in the above technical solution, the reaction temperature in the second step is selected from 100-150°C.
[0020] Furthermore, in the above technical solution, the slight vacuum in the second step is selected from 8-10 mm water column.
[0021] Advantageous Effects of the Invention
[0022] The present invention is the first to use tri(dimethylamino)borane and phenol to react under heating to obtain an intermediate, wherein the byproduct dimethylamine can be removed by tail gas absorption, thereby making the reaction proceed in a forward direction, with a high reaction yield, and thereby obtaining a dimethylamine-complexed intermediate, which has poor solubility in an organic solvent, thereby removing excess phenol. The intermediate is dissociated under slight vacuum reflux to obtain triphenyl borate, and the product purity can reach more than 99.5%, and the yield is high, which meets the process requirements of industrialized scale-up production. DETAILED DESCRIPTION
[0023] The specific embodiments of the present invention are described in detail below. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the disclosed specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.
[0024] Example 1
[0025]
[0026] In a four-necked bottle equipped with a tail gas recovery device, 329.4 g (3.5 mol) of phenol and 3000 mL of toluene were added, the temperature was raised to 40-50° C., and a mixed solution of 143 g (1 mol) of tri(dimethylamino)borane and 300 mL of toluene was slowly added dropwise under stirring. The temperature was then raised to 85-90° C. and the reaction was performed for 8 hours. GC sampling showed that 0.3% of tri(dimethylamino)borane remained. The temperature was lowered to 20-25° C. and stirred for 2 hours. The mixture was filtered, and the filter cake was slurried with toluene / dichloromethane (volume ratio 4 / 1), filtered and dried to obtain 320.8 g (0.96 mol) of the intermediate with a yield of 96.0% and an HPLC yield of 99.4%. 1 H NMR (400MHz, DMSO-d6) δ: 7.65-7.28 (m, 6H), 7.06-6.83 (m, 9H), 2.51 (s, 6H).
[0027] Example 2
[0028]
[0029] In a four-necked bottle equipped with a tail gas recovery device, 282.3 g (3.0 mol) of phenol and 2800 mL of xylene were added, the temperature was raised to 40-50° C., and a mixed solution of 143 g (1 mol) of tri(dimethylamino)borane and 300 mL of xylene was slowly added dropwise under stirring. The temperature was then raised to 90° C. for reaction for 10 hours. GC sampling showed that 0.7% of tri(dimethylamino)borane remained. The temperature was lowered to 20-25° C. and stirred for 2 hours. The mixture was filtered, and the filter cake was slurried with xylene / MTBE (volume ratio 6 / 1), filtered and dried to obtain 326.8 g (0.978 mol) of the intermediate with a yield of 97.8% and an HPLC index of 98.7%.
[0030] Example 3
[0031]
[0032] In a four-necked bottle equipped with a tail gas recovery device, 301.2 g (3.2 mol) of phenol and 2900 mL of chlorobenzene were added, the temperature was raised to 40-50 ° C, and a mixed solution of 143 g (1 mol) of tri(dimethylamino)borane and 300 mL of chlorobenzene was slowly added dropwise under stirring, and then the temperature was raised to 85-90 ° C to react for 16 hours. GC sampling showed that 0.3% of tri(dimethylamino)borane remained. The temperature was lowered to 20-25 ° C and stirred for 2 hours, filtered, and the filter cake was slurried with chlorobenzene / dichloromethane (volume ratio 4.5 / 1), filtered and dried to obtain 318.5 g (0.95 mol) of the intermediate with a yield of 95.3% and HPLC 99.1%.
[0033] Example 4
[0034]
[0035] In a four-necked bottle equipped with a tail gas recovery and reflux device, 250.7 g (0.75 mol) of the intermediate and 3000 mL of toluene were added. The mixture was stirred and refluxed under 8 mm water column for 18 hours. The intermediate residue was 0.17% after sampling by HPLC. The mixture was cooled to 10-15°C and filtered. The filtrate was distilled under reduced pressure to remove toluene. 600 mL of n-heptane was added to replace the toluene. Subsequently, 1500 mL of n-heptane was added to precipitate a white solid. The solid was slurried at room temperature and filtered. The filter cake was rinsed with fresh n-heptane and dried to obtain 197.6 g of triphenylborate with a yield of 90.8% and a GC of 99.7%. 1 H NMR (400MHz, CDCl3):7.41-7.20(m,6H),7.20-7.08(m,9H).
[0036] Example 5
[0037]
[0038] In a four-necked bottle equipped with an exhaust gas recovery and reflux device, 250.7 g (0.75 mol) of the intermediate and 3000 mL of xylene were added to the mixture. The mixture was stirred and refluxed under a 10 mm water column for 9 hours. The intermediate remained at 0.22% after sampling by HPLC. The mixture was cooled to 10-15°C and filtered. The filtrate was distilled under reduced pressure to remove xylene. 600 mL of n-heptane was added to replace the xylene. Subsequently, 1500 mL of n-heptane was added to precipitate a white solid. The solid was slurried at room temperature and filtered. The filter cake was rinsed with fresh n-heptane and dried to obtain 196.7 g of triphenylborate with a yield of 90.4% and a GC of 99.8%.
[0039] The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention, and the protection scope of the present invention shall be subject to the attached claims.
Claims
1. A method for preparing triphenylborate, characterized in that: The steps include: Step 1: Mix phenol and an organic solvent, add tri(dimethylamino)borane solution dropwise, then slowly heat up to react and bring out dimethylamine, cool down and filter to obtain an intermediate; Step 2: Mix the intermediate with an organic solvent, reflux under a slight vacuum to react and bring out dimethylamine, then cool and filter, evaporate the filtrate under reduced pressure to remove the solvent, add n-heptane to replace it, cool and crystallize and filter to obtain triphenylborate.
2. A method for preparing triphenylborate according to claim 1, characterized in that: In the first step, the organic solvent is selected from toluene, xylene or chlorobenzene.
3. A method for preparing triphenylborate according to claim 1, characterized in that: In the first step, the reaction temperature is selected from 40-90°C.
4. A method for preparing triphenylborate according to claim 1, characterized in that: In the first step, the molar ratio of tri(dimethylamino)borane to phenol is 1:3.0-3.
5.
5. A method for preparing triphenylborate according to claim 1, characterized in that: In the second step, the organic solvent is selected from toluene or xylene.
6. A method for preparing triphenylborate according to claim 1, characterized in that: In the second step, the reaction temperature is selected from 100-150°C.
7. A method for preparing triphenylborate according to claim 1, characterized in that: In the second step, the slight vacuum is selected to be 8-10 mm water column.