Method for producing 9-fluorenone

Abstract

The invention relates to a method for producing 9-fluorenone, comprising the following steps of: (1) feeding industrial fluorine as a raw material and methylbenzene as a solvent into a reaction kettle according to the weight ratio of 1:(6-8) with quaternary ammonium salt as a catalyst; heating the mixture to 40-80DEG C; adding the catalyst after the raw material is completely dissolved at the addition of 5-20 percent of industrial fluorine; introducing the air according to 2-3m<3> / h of each kilo of industrial fluorine and reacting under the condition of 40-80DEG C for 2-5h; (2) after the reaction is ended, pouring a reactant into a distillation kettle for distillation at normal temperature, recovering the solvent and obtaining an industrial fluorine crude product from the bottom of the kettle; and (3) recrystallizing the crude product with the solvent to obtain fluorenone with the content of 99 percent. The method has the advantages of simple process flow, fewer reactants and low cost, is easy to control and can be widely used for producing the fluorenone; and the finished products prepared by the method have favorable quality.

Description

technical field [0001] The invention relates to a method for producing chemical raw materials, in particular to a method for producing 9-fluorenone. Background technique [0002] 9-Fluorenone, commonly known as fluorenone, also known as benzophenone, is a yellow orthorhombic crystal with a melting point of 84°C and a boiling point of 341.5°C. Fluorenone is an important fine chemical raw material with a relatively high price. Fluorenone can be obtained by catalytic oxidation of fluorene. There are many reports on the preparation methods of fluorenone. Foreign countries such as Japan, Germany, the former Soviet Union, India, France, the United States and other countries have proposed many preparation methods, mainly as follows: [0003] (1) Liquid-phase oxidation method: Dissolve fluorene in an organic solvent and oxidize it with an oxidizing agent such as sodium dichromate or tert-butyl hydroperoxide to obtain fluorenone. [0004] (2) Air liquid-phase oxidation method: diss...

AI Technical Summary

Problems solved by technology

[0006] The liquid-phase oxidation method is suitable for small-scale production, which involves the recycling of organic solvents; the reaction temperature of the gas-phase catalytic oxidation method is high, and the process is not easy to control; the catalyst is required to have high selectivity, which increases the production cost; and the product yield is low. High; in contrast, the air liquid phase oxidation method has the advantages of low reaction temperature, high yield, easy control of the reaction process, and simple reaction device, but the current process of preparing fluorenone by air liquid phase oxidation method is more complicated. There are many kinds of catalysts, resulting in high cost and unstable reaction process, which affects the quality of finished products