阅读说明：本技术 一种9,9-二甲基氧杂蒽的制备方法 (Preparation method of 9, 9-dimethyl xanthene ) 是由 郑付伟 韩福娇 陈海涛 李德锦 杨柳 王文新 于 2020-08-14 设计创作，主要内容包括：本发明涉及一种工业催化剂Xantphos的重要原料9,9-二甲基氧杂蒽的安全高效制备方法,属精细化工技术领域。所述制备方法以二苯醚、丙酮和酸催化剂的为原料,原料摩尔比为1：1：2~5,采用一锅法制备9,9-二甲基氧杂蒽,收率可达70~75%,含量99%以上。该法采用酸催化活化丙酮与二苯醚进行亲电取代反应,替代传统工艺中使用极度危险的三甲基铝与占吨酮反应,具有原料廉价易得、操作安全、反应速度快、生产设备要求低等特点。本发明极大地降低了产品生产难度,可快速提高9,9-二甲基氧杂蒽产量。(The invention relates to a safe and efficient preparation method of an important raw material 9, 9-dimethyl xanthene of an industrial catalyst Xantphos, belonging to the technical field of fine chemical engineering. The preparation method takes diphenyl ether, acetone and an acid catalyst as raw materials, and the molar ratio of the raw materials is 1: 1: 2-5, preparing 9, 9-dimethyl xanthene by a one-pot method, wherein the yield can reach 70-75%, and the content is more than 99%. The method adopts acid-catalyzed activated acetone and diphenyl ether to carry out electrophilic substitution reaction to replace the extremely dangerous reaction of trimethyl aluminum and xanthone in the traditional process, and has the characteristics of cheap and easily-obtained raw materials, safe operation, high reaction speed, low requirement on production equipment and the like. The invention greatly reduces the production difficulty of the product and can quickly improve the yield of the 9, 9-dimethyl xanthene.)

1. A preparation method of 9, 9-dimethylxanthene is characterized by comprising the following steps: diphenyl ether and acetone are used as raw materials, inorganic or organic acid is used as a catalyst, heating reaction is carried out, cooling to room temperature is carried out after the reaction is finished, the reaction system is poured into ice water, sodium hydroxide aqueous solution is added into the reaction system, and the pH value is adjusted to be neutral under stirring; extracting, drying an organic layer, performing rotary evaporation to obtain a crude product, and recrystallizing to obtain a target product;

the catalyst is concentrated sulfuric acid, polyphosphoric acid, methanesulfonic acid or trifluoromethanesulfonic acid.

2. The method according to claim 1, wherein the molar ratio of the diphenyl ether to the acetone to the catalyst is: 1: 1: 2 to 5.

3. The method according to claim 1, wherein the reaction temperature is 80 to 120 ℃.

4. The process for producing 9, 9-dimethylxanthene according to claim 1, wherein the extracting agent is selected from dichloromethane; a dichloromethane/methanol solution with a volume ratio of 1:1 is used for recrystallization.

Technical Field

The invention belongs to the technical field of fine chemical engineering, and relates to a preparation method of 9, 9-dimethyl xanthene.

Background

The 9, 9-dimethyl xanthene is an important fine chemical intermediate, is mainly used for preparing an industrial phosphorus ligand catalyst 4, 5-bis (diphenylphosphino) -9, 9-dimethyl xanthene (xanthhos), and a derivative of the 9, 9-dimethyl xanthene has excellent hole transport performance, can also be used in the fields of liquid crystal materials, solar cells, catalytic materials and the like, and particularly, a downstream product of the xanthene is widely applied to coupling reactions of palladium-catalyzed Suzuki (Suzuki), Negishi (Negishi), Stille (Stille), Heck (Heck) and the like by virtue of a special structure. With the annual increase in the demand of Xantphos in the pharmaceutical and optoelectronic material industries, the annual demand for the phosphorus ligand in the market is expected to be over 20 tons in the coming years.

Disclosure of Invention

In order to overcome the defects of large operation risk, high requirement on production equipment and low production efficiency in the existing 9, 9-dimethylxanthene production process, the invention aims to provide a safe and efficient preparation method of 9, 9-dimethylxanthene, which solves the problems of high risk, high requirement on equipment, low production efficiency and the like in the production process.

The invention solves the technical problem by adopting the following technical scheme:

the preparation method takes diphenyl ether and acetone as reaction raw materials, and takes concentrated sulfuric acid, polyphosphoric acid, methanesulfonic acid, trifluoromethanesulfonic acid and the like as acid catalysts to prepare and produce the 9, 9-dimethylxanthene.

According to a preferred embodiment, the reaction scheme of the preparation process according to the invention is as follows:

adding diphenyl ether, acetone and an acid catalyst into a three-neck flask provided with a stirrer and a thermometer, heating for reaction, cooling to room temperature, pouring into ice water, adding a sodium hydroxide aqueous solution into a reaction system, and adjusting the pH to be neutral under stirring. Extracting, drying the organic layer and then carrying out rotary evaporation to obtain a crude product. And recrystallizing to obtain the high-purity product.

According to a preferred embodiment, the molar ratio of diphenyl ether, acetone and acid catalyst according to the invention is 1: 1: 2 to 5.

According to a preferred embodiment, the reaction temperature is 80-120 ℃.

According to a preferred embodiment, the reaction time is 2-5 h.

According to a preferred embodiment, the concentration of the aqueous sodium hydroxide solution in the preparation method is 20-50%. The purpose of adding sodium hydroxide is to neutralize excess acid, reduce the solubility of the product in water, and also prevent the problem that when organic acid catalysis is used, the acid is not neutralized, so that the organic acid is extracted into dichloromethane, and the difficulty of post-treatment is increased.

According to a preferred embodiment, the molar ratio of the sodium hydroxide to the acid catalyst in the preparation method is 1: 1-2.

The invention has the following beneficial effects:

the preparation method of 9, 9-dimethyl xanthene provided by the invention takes diphenyl ether and acetone as reaction raw materials, and takes concentrated sulfuric acid, polyphosphoric acid, methanesulfonic acid, trifluoromethanesulfonic acid and the like to catalyze and replace the traditional production method of flammable and explosive substances such as trimethyl aluminum and n-butyllithium, so that the danger of the production operation process and the special requirements of production equipment are greatly reduced, the method has the characteristics of high reaction speed, high production efficiency, cheap and easily available raw materials, and production by a conventional production device, the production cost is greatly reduced, the yield of the product can reach 70% -75% after optimization, and the content is more than 99%. The method can quickly improve the productivity of the 9, 9-dimethylxanthene, fills the market vacancy caused by the insufficient productivity due to the great production difficulty of the old process, and is favorable for popularization and application.

Drawings

FIG. 1 is an HPLC chromatogram of a target product of the present invention.

FIG. 2 is a nuclear magnetic hydrogen spectrum of the target product of the present invention.

FIG. 3 is a nuclear magnetic carbon spectrum of the target product of the present invention.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the implementation of the present invention.