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Synthesis method of amino substituted 2-phenylbenzimidazole derivative

A technology of phenylbenzimidazoles and synthesis methods, which is applied in the field of synthesis of 2-phenylbenzimidazole derivatives, and can solve problems such as harsh conditions, low cost, and large pollution of benzimidazole monomers

Inactive Publication Date: 2017-12-15
浙江清和新材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, the synthesis of benzimidazole monomer still has the disadvantages of high pollution, high cost and harsh conditions.
French patent FR2502151 uses 1-amino-2,4-dinitrobenzene and 4-nitrobenzoyl chloride as raw materials to obtain 2-(4-aminophenyl)-5-aminobenzene through condensation, hydrogenation and cyclization And imidazole, but a large amount of HCl acid gas will be produced during the reaction condensation process, which is not friendly to the environment; at the same time, hydrochloric acid needs to be added in the hydrogenation process, and alkali neutralization must be strengthened in the cyclization process, resulting in a large amount of high-salt wastewater
Chinese patent CN101397275A uses 4-nitrobenzoyl chloride and 4-nitro-o-phenylenediamine as raw materials to synthesize products through condensation, cyclization, and hydrogenation. Although there is no high-salt wastewater, a large amount of HCl is still produced during the condensation process. Gas, and the price of 4-nitro-o-phenylenediamine is relatively high, and the cost is not dominant

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Add 18.3 g of p-nitrobenzoic acid, 20.1 g of 2,4-dinitroaniline, 200 mL of toluene and 1.0 g of boric acid into a 500 mL four-neck flask, heat to boiling, reflux to separate water to remove the generated moisture, and react 6 h, cooled, filtered, and dried to obtain 30.5 g of N-(4-nitrobenzoyl)-2,4-dinitroaniline as a solid, with an HPLC purity of 93.5% and a yield of 78.3%.

[0020] Add the obtained amide, 200 mL of absolute ethanol, and 0.15 g of 5% Pd / C into a 500 mL autoclave, 80 o C, H 2 Pressure 8 MPa, react for 5 h, lower the temperature and open the kettle, filter and recover the catalyst, N 2 Under atmospheric pressure, the filtrate was distilled off under normal pressure to remove 150 mL of solvent, added 100 mL of purified water, and cooled to 20 o C, filtered to obtain 20.1 g of 2-(4-aminophenyl)-5-aminobenzimidazole, the HPLC purity was 95.7%, and the yield was 93.5%.

Embodiment 2

[0022] Add 18.3 g of m-nitrobenzoic acid, 22.5 g of 2,4-dinitroaniline, 200 mL of m-xylene, and 0.5 g of boric acid into a 500 mL four-neck flask, heat to boiling, reflux to separate water to remove the generated moisture, Reacted for 12 h, cooled, filtered, and dried to obtain 25.5 g of N-(3-nitrobenzoyl)-2,4-dinitroaniline as a solid, with an HPLC purity of 91.0% and a yield of 63.8%.

[0023] Add the obtained amide, 200 mL acetic acid, and 0.20 g 5% Pd / C into a 500 mL autoclave, 110 o C, H 2 Pressure 6 MPa, react for 4 h, lower the temperature and open the kettle, filter and recover the catalyst, N 2 Under the atmosphere, distill the filtrate under normal pressure to remove 150 mL of solvent, add 100 mL of purified water, and cool to 20 o C, filtered to obtain 16.2 g 2-(3-aminophenyl)-5-aminobenzimidazole, HPLC purity 96.2%, yield 90.5%.

Embodiment 3

[0025] Add 20.0 g of p-nitrobenzoic acid, 20.1 g of 2,3-dinitroaniline, 200 mL of p-xylene and 0.2 g of metaboric acid into a 500 mL four-neck flask, heat to boiling, reflux and separate water to remove the generated moisture , reacted for 24 h, cooled, filtered, and dried to obtain 21.0 g of N-(4-nitrobenzoyl)-2,3-dinitroaniline as a solid, with an HPLC purity of 96.5% and a yield of 55.7%.

[0026] Add the obtained amide, 200 mL of anhydrous tetrahydrofuran, and 0.1 g of 5% Pd / C into a 500 mL autoclave for 80 o C, H 2 Pressure 8 MPa, react for 5 h, lower the temperature and open the kettle, filter and recover the catalyst, N 2 Under the atmosphere, distill the filtrate under normal pressure to remove 150 mL of solvent, add 100 mL of purified water, and cool to 20 o C, filtered to obtain 12.1 g 2-(4-aminophenyl)-4-aminobenzimidazole, HPLC purity 94.7%, yield 80.8%.

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PUM

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Abstract

The invention relates to a synthesis method of an amino substituted 2-phenylbenzimidazole derivative. The method uses cheap and easily available nitro substituted benzoic acid compound and dinitraniline compound as the raw materials for condensation to obtain an amide compound, then catalytic hydrogenation is carried out, and simultaneously cyclization is conducted to obtain the benzimidazole derivative. The reaction is green and efficient, the operation is simple and the yield is excellent.

Description

technical field [0001] The invention relates to a synthesis method of amino-substituted 2-phenylbenzimidazole derivatives. Background technique [0002] Amino-substituted benzimidazole compounds, especially 2-(4-aminophenyl)-5-aminobenzimidazole (APABI), are a class of good polymer monomers for the synthesis of polyimide Amine film materials are widely used in high-performance computers, workstations, telecommunications industry and aerospace equipment; they can also be used to synthesize polyaminoimide materials, suitable for motors, aircraft, auto parts and radiation-resistant materials, etc.; It can also be used to synthesize poly(ether amide), and can be used to prepare semi-permeable membranes for filtering aqueous solutions and purified water; at the same time, flexible printed circuit boards can be prepared by combining APABI-polyimide polymer films with copper foil glue, and the polymerization of APABI The modified material is the first choice material for liquid cr...

Claims

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Application Information

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IPC IPC(8): C07D235/18
Inventor 林桂海洪俊杰董刘宏范占成张爱珠张增礼冯珍会
Owner 浙江清和新材料科技有限公司
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