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Method for preparing 2-( p-aminophenyl) benzimidazole-5-amine

A technology of p-aminophenyl and benzimidazole, which is applied in the field of preparation of 2-benzimidazol-5-amine, can solve problems such as difficulty in obtaining, difficulty in industrialization process, and great difficulty, and achieves short synthesis route and reduction technology Environmental protection and high production efficiency

Inactive Publication Date: 2009-04-01
ZHEJIANG DRAGON CHEM CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

(2) in Table 1 is the French patent FR2502151, its synthetic raw materials are relatively cheap, but the final step of the reduction process is to convert three NO 2 reduced to three NH 2 , has high requirements on the catalyst and is too difficult
(3) in Table 1 is British Patent GB2125791, and one of its condensed reactant raw materials is expensive and difficult to obtain
(4) is the Russian patent SU498298, there are three amine groups in the reactant, all three positions of the condensation reaction may react, obviously the selectivity of the reactant is relatively poor
In addition, another feature of them is the use of iron-based catalysts or SnCl in catalytic reduction. 2 Catalysts not only have low catalytic efficiency, but also cause great environmental pollution. Restricted by the environmental protection departments of various countries, the industrialization process is full of difficulties

Method used

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  • Method for preparing 2-( p-aminophenyl) benzimidazole-5-amine
  • Method for preparing 2-( p-aminophenyl) benzimidazole-5-amine
  • Method for preparing 2-( p-aminophenyl) benzimidazole-5-amine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Add 150g of 1-methyl-2-pyrrolidone into a 500mL four-neck flask, add 25g of DANB and 32g of NBC under stirring, then raise the temperature to 185-190°C at 5°C / min, and keep the temperature constant for 3hr. After sampling, perform HPLC analysis to control the condensate content to <1.0%. After passing the analysis, cool the reaction solution to 100°C. Then slowly pour the reaction solution into 300g of normal temperature methanol prepared in advance, stir slowly until the product is precipitated, stop stirring, let stand to cool to room temperature, filter and drain. The filter cake was beaten with 300g of anhydrous methanol at room temperature for 30min, filtered and drained. Finally, the NBIA sample was obtained by circulating hot air at 60° C. for 24 hours. The HPLC purity was 98.86%, and the yield was 86.00%.

Embodiment 2

[0035] Add 150g of 1-methyl-2-pyrrolidone into a 500mL four-neck flask, add 25g of DANB and 32g of NBC under stirring, then raise the temperature to 130-135°C at 5°C / min, and keep the temperature constant for 3hrs. Then the reaction solution was cooled to 100°C and slowly poured into 300g of methanol at room temperature prepared in advance, stirred slowly until the product was precipitated, then stopped stirring, left to cool to room temperature, filtered and drained. The filter cake was beaten with 300g of anhydrous methanol at room temperature for 30min, filtered and drained. Finally, the NBIA sample was obtained by circulating hot air at 60° C. for 24 hours. The HPLC purity was 86.33%, and the yield was 25.08%.

Embodiment 3

[0037]Add 150g of 1-methyl-2-pyrrolidone into a 500mL four-neck flask, add 25g of DANB and 32g of NBC under stirring, then raise the temperature to 150-155°C at 5°C / min, and keep the temperature constant for 3hrs. Then the reaction solution was cooled to 100°C and slowly poured into 300g of methanol at room temperature prepared in advance, stirred slowly until the product was precipitated, then stopped stirring, left to cool to room temperature, filtered and drained. The filter cake was beaten with 300g of anhydrous methanol at room temperature for 30min, filtered and drained. Finally, the NBIA sample was obtained by circulating hot air at 60° C. for 24 hours. The HPLC purity was 95.89%, and the yield was 52.46%.

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Abstract

The invention relates to a preparation method of 2-(p-amino phenyl) benzimidazole-5-amic, including the following steps: (A) p-Nitro o-phenylendiamine and p-Nitro benzoyl chloride are adopted as materials which are processed through condensation, cyclization and dehydration one-pot method for synthesizing the benzimidazole compound shown as the formula (II); and (B) the compound of the formula (II) is subjected to catalytic hydrogenation to obtain the final product. The preparation method is characterized in that the manufacturing efficiency is high; and the synthesizing cycle is short and the reducing technique is environment-friendly. As a green synthesizing technique, the method overcomes the contamination problem troubling people for years.

Description

(1) Technical field [0001] The invention relates to a preparation method of 2-(p-aminophenyl)benzimidazol-5-amine. (2) Background technology [0002] As we all know, polyimide (polyimide, PI) is a kind of high molecular polymer containing imide functional groups in the main chain structure of the molecule. Among all the application fields of polyimide materials, the microelectronics industry has become the largest beneficiaries. The wide application of polyimide in this field largely benefits from the excellent comprehensive properties of polyimide materials and the modification research to meet the special functions in the field of microelectronics technology. The polymer of 2-(p-aminophenyl)benzimidazol-5-amine (referred to as: BIA) is a new generation of electronic insulating film material. The polyimide modified by BIA is characterized by its high temperature resistance and chemical resistance. Sex, high bonding strength, good bending performance, low cost, less pollut...

Claims

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Application Information

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IPC IPC(8): C07D235/18
Inventor 肖庆军叶炯英刘琛
Owner ZHEJIANG DRAGON CHEM CO LTD
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