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CN-121574064-B - Method for preparing 4-nitro-N-phenyl benzamide by one-pot method

CN121574064BCN 121574064 BCN121574064 BCN 121574064BCN-121574064-B

Abstract

The invention relates to the technical field of organic synthesis, in particular to a method for preparing 4-nitro-N-phenyl benzamide by a one-pot method, which comprises the steps of adding an inert solvent, p-nitrobenzoic acid and a composite catalyst into a reactor under the protection of inert gas, and heating and dissolving, wherein the composite catalyst comprises NFM and TPPO; slowly adding thionyl chloride into the reaction system to perform acylation reaction, slowly adding aniline into the reaction system to perform condensation reaction, and after the reaction is finished, performing aftertreatment to obtain 4-nitro-N-phenyl benzamide. The method can realize one-pot reaction without separating high-risk intermediates. NFM in the composite catalyst efficiently catalyzes acyl chloride, TPPO stabilizes an acyl chloride intermediate and promotes condensation, so that the reaction is efficiently, stably and selectively carried out, and the product yield and purity are high. And the catalyst is easy to recycle, and the process is green, safe and economic and is suitable for industrial production.

Inventors

  • HUANG AILING
  • ZHANG WENHUI
  • ZHAO XI
  • WU KAI
  • HOU CHENG
  • WANG PENG

Assignees

  • 泰和新材集团股份有限公司
  • 泰和新材(宁夏)科技研发有限公司
  • 烟台泰和新材高分子新材料研究院有限公司

Dates

Publication Date
20260512
Application Date
20260127

Claims (9)

  1. 1. The method for preparing the 4-nitro-N-phenyl benzamide by the one-pot method is characterized by comprising the following steps of: S1, adding an inert solvent, p-nitrobenzoic acid and a composite catalyst into a reactor under the protection of inert gas, and heating and dissolving, wherein the composite catalyst is NFM and TPPO, and the mass ratio of the NFM to the TPPO in the composite catalyst is 1 (0.2-0.5); S2, slowly adding thionyl chloride into a reaction system under the condition of heating and dissolving temperature, and controlling the temperature rising rate of 8-12 ℃ per 30min to be raised to 70-85 ℃ for acylation reaction; s3, slowly adding aniline into the reaction system to perform condensation reaction; S4, after the reaction is finished, obtaining the 4-nitro-N-phenyl benzamide through post-treatment.
  2. 2. The method for preparing 4-nitro-N-phenyl benzamide according to claim 1, wherein the inert solvent is at least one of tetrachloroethylene, dichloromethane, dichloroethane, N-dimethylformamide and N, N-dimethylacetamide.
  3. 3. The method for preparing 4-nitro-N-phenylbenzamide by the one-pot method according to claim 1, wherein in the step S1, the heating and dissolving temperature is 35-55 ℃, and the inert solvent is 5-8 times of the mass of p-nitrobenzoic acid.
  4. 4. The method for preparing 4-nitro-N-phenyl benzamide by using the one-pot method according to claim 1, wherein the total dosage of the composite catalyst is 1.5% -4% of the mass of p-nitrobenzoic acid.
  5. 5. The method for preparing 4-nitro-N-phenyl benzamide according to claim 1, wherein the molar ratio of thionyl chloride to p-nitrobenzoic acid is (1-2) 1, and the molar ratio of aniline to p-nitrobenzoic acid is (0.8-1.5) 1.
  6. 6. The method for preparing 4-nitro-N-phenyl benzamide according to claim 1, wherein in the step S2, the reaction time of the acylation reaction is 2-4 h.
  7. 7. The method for preparing 4-nitro-N-phenyl benzamide according to claim 1, wherein in the step S3, the condensation reaction temperature is 100-120 ℃ and the reaction time is 2-4 h.
  8. 8. The method for preparing 4-nitro-N-phenyl benzamide by the one-pot method according to claim 1, wherein in the step S4, after the reaction is finished, methanol is added for quenching reaction, and the 4-nitro-N-phenyl benzamide is obtained through solid-liquid separation, washing and vacuum drying under the condition of 50-60 ℃.
  9. 9. The method for preparing 4-nitro-N-phenyl benzamide by the one-pot method according to claim 8, wherein the mother liquor obtained by the solid-liquid separation is distilled under reduced pressure to recover methanol and an inert solvent, and the recovered TPPO and the concentrated solution containing NFM are obtained by crystallization and solid-liquid separation, and the recovered methanol, the inert solvent, the TPPO and the concentrated solution containing NFM are recycled for the preparation process of the 4-nitro-N-phenyl benzamide.

Description

Method for preparing 4-nitro-N-phenyl benzamide by one-pot method Technical Field The invention relates to a method for preparing 4-nitro-N-phenyl benzamide by a one-pot method, belonging to the technical field of organic synthesis. Background 4-Nitro-N-phenyl benzamide (4-Nitrobenzanilide) with chemical formula of C 13H10N2O3 and structural formula of。 4-Nitro-N-phenylbenzamide is a high performance material monomer that can be used to prepare 2- (4-aminophenyl) -5-aminobenzimidazole (APBIA). APBIA has important function in the preparation of polymer materials such as aramid fiber, polyimide film, polyamino imide and the like, and APBIA can be subjected to polycondensation reaction with various monomers through amino groups and imidazole rings in the molecular structure of the polymer materials to form a high-performance polymer chain structure. The structure endows the material with excellent mechanical property, thermal stability and chemical stability, so that the material is widely applied to the fields of aerospace, electronic industry, automobile industry, protective equipment and the like. APBIA not only improves the performance of the material, but also improves the processing performance of the material, has important application value and market prospect, and can be used as a medical intermediate in the field of medical synthesis. The preparation of 4-nitro-N-phenylbenzamide disclosed in U.S. Pat. No. 3, 20220177416A1 is carried out by reacting 3-nitrobenzaldehyde with aniline to prepare 4-nitro-N-phenylbenzoyl, but the yield of the product of the preparation is relatively low, only 66%. In addition, if p-nitrobenzoic acid is directly adopted to directly react with aniline to prepare 4-nitro-N-phenylbenzamide, the reaction usually needs to use higher reaction temperature (more than or equal to 200 ℃), the energy consumption is higher, and the method is not suitable for industrial application. The 4-nitro-N-phenylbenzamide disclosed in the publication No. US20160136166A1 is prepared by adding 4-nitrobenzoic acid to methylene chloride and ClCOCOCl, dropwise adding N, N-dimethylformamide under stirring, stirring the mixture at room temperature for reaction, adding a methylene chloride solution of PhNH to the residue, dropwise adding triethylamine under stirring at 0 ℃, stirring the obtained solution at room temperature overnight, washing the obtained mixture with HC solution and brine, drying over anhydrous sodium sulfate and concentrating in vacuo, diluting the residue with a mixed solvent of petroleum ether and ethyl acetate, and collecting the solid by filtration. Therefore, the development of a method which has simple preparation method, high yield and high product purity and can realize the one-pot method for preparing the 4-nitro-N-phenyl benzamide has important value. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a method for preparing 4-nitro-N-phenyl benzamide by a one-pot method, which is simple to operate, has high yield and high purity of the target product 4-nitro-N-phenyl benzamide, and is suitable for industrialized application. The technical scheme for solving the technical problems is as follows: The preparation method of the 4-nitro-N-phenyl benzamide by a one-pot method comprises the following steps: S1, under the protection of inert gas, adding an inert solvent, p-nitrobenzoic acid and a composite catalyst into a reactor, and heating and dissolving, wherein the composite catalyst comprises NFM and TPPO; S2, slowly adding thionyl chloride into the reaction system to carry out acylation reaction; s3, slowly adding aniline into the reaction system to perform condensation reaction; S4, after the reaction is finished, obtaining the 4-nitro-N-phenyl benzamide through post-treatment. Further, the inert solvent is at least one of tetrachloroethylene, dichloromethane, dichloroethane, N-dimethylformamide and N, N-dimethylacetamide. In the step S1, the heating and dissolving temperature is 35-55 ℃, and the mass of the inert solvent is 5-8 times of that of the p-nitrobenzoic acid. Further, the mass ratio of the NFM to the TPPO in the composite catalyst is 1 (0.2-0.5). Further, the total dosage of the composite catalyst is 1.5-4% of the mass of the p-nitrobenzoic acid. Further, the molar ratio of the thionyl chloride to the p-nitrobenzoic acid is (1-2) 1, and the molar ratio of the aniline to the p-nitrobenzoic acid is (0.8-1.5) 1. In step S2, thionyl chloride is slowly added into the reaction system under the condition of heating and dissolving temperature, and then the temperature rising rate of 8-12 ℃ per 30min is controlled to rise to 70-85 ℃ for carrying out the acylation reaction, wherein the reaction time of the acylation reaction is 2-4 h. Further, in the step S3, the condensation reaction temperature is 100-120 ℃ and the reaction time is 2-4 h. Further, in the step S4, after the reaction is finished, methanol is added for quenching re