The invention discloses a method for producing 9-fluorenone by oxidizing fluorine The method comprises the following steps of: dissolving industrial fluorine as a raw material in to a halogenated hydrocarbon solvent at the temperature of 30-80 DEG C, adding sodium hydroxide and a quaternary ammonium salt which are cheaper than potassium hydroxide for serving as catalysts, reacting in a reaction kettle for 05-5 hours, separating a liquid, and distilling an organic phase under reduced pressure for removing the solvent to obtain an intermediate substance; adding an intermediate and an alcohol solvent into the reaction kettle, heating to 40-80 DEG C for dissolving, introducing air at the speed of 1-10m /h into every kilogram of industrial fluorine, and reacting for 05-5 hours; and after the reaction, removing the solvent under reduced pressure, cooling and crystallizing simultaneously, and filtering a crystal product to obtain fluorenone The equipment investment is low, process operation is easy, the solvent can be recycled, and cost is effectively saved; an obtained fluorenone product has high purity and high yield; in an entire process, an industrial grade organic solvent is adopted, so that operation and running costs are low; and an entire device is controlled automatically, so that operation conditions are improved, and the product quality stability is ensured simultaneously

Method for producing 9-fluorenone by oxidizing fluorene

The invention discloses a method for preparing 9-fluorenone via four-phase transfer catalysis. At a lower temperature, alkali is taken as a catalyst, quaternary ammonium salt serves as a phase transfer agent, fluorene can be excessive and reacts with oxygen-containing gas in xylene in states of dissolution and suspension, and high-purity 9-fluorenone is directly obtained, a right reaction condition is selected, and the transformation rate of the fluorene can reach 100 percent. According to the invention, the recovered alkali and the dissolvent do not need to be treated complexly and particularly, reuse can be realized, and industrialization is facilitated; in addition, mixed xylene and water are taken as the dissolvent, the oxidation of the fluorene as the reaction condition of the 9-fluorenone, the selection of the catalyst alkali and phase transfer agent, and the reuse of the dissolvent and the alkali are researched, as a result, the conditions of high transmission rate of fluorene and high selective transmission of the 9-fluorenone are obtained, and a more complete compounding process is disclosed.

Method for preparing 9-fluorenone via four-phase transfer catalysis

The invention relates to a preparation method for a medicine KCNQ potassium channel conditioning agent critical material 2-bromine-4,6-dichloroaniline According to the invention, 2,4-dichloroaniline is taken as a raw materials, and is subjected to NBS (N-bromosuccinimide) bromination to obtain a target object, and the preparation method of the invention has the advantages of low preparation method and simple operation, and has industrial production value

2-bromine-4,6-dichloroaniline preparation method

The invention discloses a method for preparing high-purity 9-fluorenone from high-purity fluorene The high-purity 9-fluorenone is prepared by using high-purity fluorene as a raw material, alkali as a catalyst, an aromatic organic solvent and water as a solvent and a quaternary ammonium salt as a phase transfer agent The preparation method disclosed by the invention comprises the steps of purifying industrial fluorene of which the purity is more than or equal to 95% at first, and then preparing the 9-fluorenone by using the high-purity fluorene, so that a purification process of the product namely 9-fluorenone which is difficult to purify is avoided, and the preparation process is simplified Under the condition of the invention, the conversion rate of fluorene can reach 100%, and fluorenone with the purity of 100% can be obtained; after a reaction solution is cooled and crystal fluorenone is separated out, the filtrate containing the alkali, quaternary ammonium salt, fluorene and fluorenone is directly recycled, and a high-boiling-point solvent is used for absorbing the solvent in the reaction tail gas, so that the method is an energy-saving and environment-friendly chemical process

Method for preparing high-purity 9-fluorenone from high-purity fluorene

The invention relates to a one-pot method for preparation of 5-Bromo-m-xylene. The one-pot method comprises steps as follows: (a) glacial acetic acid and dimethylaniline are sequentially added to a reaction container, a sulfuric acid solution is dropwise added, liquid bromine is dropwise added while the temperature is kept ranging from 30 DEG C to 40 DEG C, and the mixture is stirred to react for 0.5-1 h; (b) the reaction container is put in an ice bath, a sodium nitrite solution is dropwise added at the temperature kept at 5 DEG C or blow, and the mixture is stored under a heat preservation condition after the sodium nitrite solution is dropwise added; (c) hypophosphorous acid is cooled to 5 DEG C or below, copper sulfate is added, and a mixture is formed, dropwise added to the reaction container in the step (b), then heated to 15-30 DEG C to react over a night and left to stand for layering; (d) an organic layer is sequentially washed with water and a saturated sodium bicarbonate solution. Equipment investments and tedious operations are greatly reduced, the amount of produced waste water is reduced, and the method is more environment-friendly.

One-pot method for preparation of 5-Bromo-m-xylene

The invention relates to the technical field of production of an aromatic compound 9-fluorenone, in particular to a preparation method of the 9-fluorenone. The preparation method includes the steps as follows: 1) taking industrial fluorene, benzene series solvent, sodium hydroxide and quaternary ammonium salt, and adding the four components in a four-mouth bottle; 2) stirring the mixture in normal pressure, increasing the temperature to above 90 DEG C, reacting, and introducing air for oxidization; 3) conducting reduced-pressure distillation and allowing concentrate to crystallize, thus obtaining yellow fluorenone crystals; and 4) washing the fluorenone crystals for one time and then drying the fluorenone crystals, thus obtaining the 9-fluorenone product. The benzene series solvent is toluene or dimethylbenzene. Compared with the prior art, the preparation method has the benefits as follows: 1) the reaction temperature is low, the operation is simple and convenient and the reaction conditions are moderate; 2) the cheap sodium hydroxide is taken as a catalyst, so the cost is low; 3) the benzene series solvent can be recycled by reduced-pressure distillation, washing water is little in quantity, treatment is easy and pollution to environment is small; and 4) the gas chromatographic purity of the product is higher than 99.2%, the yield is higher than 86.7% and the production requirements are met.

Preparation method of 9-fluorenone

The invention relates to a method for preparing 3, 5-dimethyl bromobenzene. Firstly, hydrobromic acid and 2, 4-dimethylaniline are mixed and stirred into salt; then oxydol is dripped at certain temperature to finish bromination reaction; a crude brominated product is put into hydrochloric solution directly; sodium nitrite solution is dripped for diazotizing; and hydrolysis is finished in the presence of cuprous chloride and hypophosphorous acid to obtain the solution of crude 5-dimethyl bromobenzene which is rectified and purified finally to ensure that the purity is more than 99.5 percent. In the method, the hydrobromic acid is used as the solvent of the bromination reaction instead of DMSO and the oxydol is used as an oxidant, thereby avoiding the process that the product is washed and separated in mass when DMSO is used; the process for separating the product is simplified, thereby improving the yield and radically solving the problem that the solvent is difficult to be separated from water and can not be recycled; the excessive hydrobromic acid during the production can be disposed simply for recycling; and the production cost is lowered greatly.

Process for producing 3,5-dimethyl bromobenzene

The invention relates to a method for preparing trimethylsilyl acetylene, which is characterized by comprising the following steps: taking 2-methyl tetrahydrofuran saturated by acetylene as a format reaction solvent and dropwise adding into reaction liquid obtained by the format reaction of magnesium powder and halogenated hydrocarbon to obtain a mixed solution; dropwise adding a 2-methyl tetrahydrofuran solution and a trimethyl chlorosilane solution into the mixed solution and heating to obtain reaction liquid; and distilling the reaction liquid under a protection condition of nitrogen gas at normal pressure and collecting distillate below 52-54 DEG C to obtain a finished product of the trimethylsilyl acetylene. The invention has the advantages of avoiding a process of separating products by water washing in a large amount and enhancing the yield because of the simplification of the process of separating the products. The problems of difficult separation of a solvent and water and unable recovery for use are fundamentally solved, and no water can be realized after the 2-methyl tetrahydrofuran solvent which is distilled out in production is distilled and processed for recycle.

Shoukai Wang

Papers

Preparation method of 9-fluorenone

Process for producing 3,5-dimethyl bromobenzene

Method for preparing trimethylsilyl acetylene