A kind of preparation method of p-nitroacetophenone

Abstract

The invention discloses a preparation method of p-nitroacetophenone. The method is specifically carried out according to the following steps: using p-nitroethylbenzene as a raw material, under the action of a metal porphyrin catalyst, the Under atmosphere, under solvent-free conditions, react in an autoclave at 110-150° C. for 6 hours, and the obtained reaction mixture is post-processed to obtain the target product nitroacetophenone. The method of the present invention reacts in a closed autoclave, which can greatly reduce the volatilization loss of raw materials, and can also avoid the discharge of reaction waste gas, and avoid the resulting environmental pollution problems; this technology does not require solvents in the entire oxidation process , avoiding the consumption of organic solvents and the environmental problems brought about by them, reducing the production cost and improving the production efficiency.

Description

[0001] (1) Technical field: [0002] The technology relates to a preparation method of p-nitroacetophenone. [0003] (two) background technology: [0004] p-Nitroacetophenone is an important organic synthesis intermediate widely used in medicine (Bioorganic & Medicinal Chemistry Letters, 2010, 20, 4168), pesticide (Bioorganic & Medicinal Chemistry Letters, 2010, 20, 4693), dye synthesis and other fields . In the process of producing p-nitroacetophenone, since the functional group (nitro, acetyl group) of p-nitroethylbenzene belongs to the meta-positioning group, the nitration of nitrobenzene and the nitration of acetophenone make the preparation target The product is relatively difficult, so most of them use the method of selective oxidation of the benzylic C-H bond of the aryl side chain to prepare the target product, and the oxidant is mainly KMnO 4 、H 2 o 2 , t-BOOH, etc. (Tetrahedron, 2002, 58, 9879) are highly oxidizing chemical reagents. The catalysts often use mangan...

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Problems solved by technology

[0006] (2) CN 102532200A (public date: July 4, 2012) discloses the synthesis and application of a complex involving N,N-coordinated dimeric rhodium (II), which exhibits Good activity, the method uses 1.0mol% of the above-mentioned complex as a catalyst, the oxidizing agent is 4.0 equivalents of tert-butyl hydroperoxide aqueous solution, water is used as a solvent, and reacts at room temperature for 20 hours, and the p-nitrogen can be obtained with a yield of 82%. The advantage of this method is that the reaction conditions are mild, the yield is high, and water is used as the solvent. The disadvantage is that a specific catalyst is required, and the concentration of the substrate is small, so it is difficult to achieve scale-up and industrial production.

The disadvantage of this method is to carry out high-temperature initiation, and the temperature is high. During the process of using oxygen bubbling, the loss of oxygen is large, which is uneconomical.

[0013] (9) Katsuhiko Moriyama (Organic Letters, 2012, 14, 2414) et al reported the use of free radical initiator KBr (1.5eq.), using visible light to selectively catalyze the oxidation of the C-H bond at the benzylic position of aromatic hydrocarbons, Oxone (1.2eq. ) is the most oxidizing agent, using solvent CH 2 Cl 2 -H 2 O (9:1), react at room temperature for 24 hours, and the yield of p-nitroacetophenone can reach 96%.

The advantages of the new process are atmospheric pressure oxidation, high product yield, and reduced tail gas, which is suitable for industrial production; the disadvantage is that the amount of catalyst used is relatively large, and it pollutes the environment and the production cost is high.

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