Preparation method of 4-methoxy-2-nitroaniline

A technology of methoxyaniline and nitroaniline, which is applied in the field of preparation of 4-methoxy-2-nitroaniline, can solve the problems of long reaction route, low process yield, harsh reaction conditions, etc. Reduced risk factor, simple reaction operation, and reduced production costs

CN114213261AActive Publication Date: 2022-03-22SHANDONG FIRST MEDICAL UNIV & SHANDONG ACADEMY OF MEDICAL SCI
2 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-03-22

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a preparation method of 4-methoxy-2-nitroaniline, and relates to the technical field of synthesis of medical intermediates, and the preparation method comprises the following steps: dissolving N-benzenesulfonyl-4-methoxyaniline in 1, 2-dichloroethane, reacting with copper nitrate trihydrate in the presence of pyridine to obtain N-benzenesulfonyl-4-methoxy-2-nitroaniline, and reacting with 1, 2-dichloroethane to obtain N-benzenesulfonyl-4-methoxy-2-nitroaniline. Then dissolving the N-benzenesulfonyl-4-methoxy-2-nitroaniline in 1, 2-dichloroethane, adding p-toluenesulfonic acid under the condition of argon protection, and carrying out a reaction so as to obtain 4-methoxy-2-nitroaniline; the synthetic route is mild in reaction condition, simple in reaction and post-treatment process operation, relatively low in reaction danger coefficient and low in production cost, reduces the environmental problems caused by the traditional nitration reaction, meets the requirements of green chemistry, has relatively high application value and relatively good economic benefits, and is suitable for industrial large-scale production.
Need to check novelty before this filing date? Find Prior Art

Description

Technical field

[0001] The invention relates to the technical field of chemical intermediate synthesis, and specifically relates to a preparation method of 4-methoxy-2-nitroaniline. Background technology

[0002] 4-Methoxy-2-nitroaniline is an important organic synthesis intermediate with broad application prospects, and can be mainly used in the preparation of omeprazole. The synthesis of this compound in the prior art has the disadvantages of harsh reaction conditions, low process yield, and long reaction route. Contents of the invention

[0003] The object of the present invention is to provide a preparation method of 4-methoxy-2-nitroaniline. This preparation method does not use highly polluting reagents, the overall reaction temperature does not exceed 100°C, the reaction conditions are mild, and it is more effective than the existing technology. Improves process yield and is suitable for industrial-scale production.

[0004] In order to achieve the above object, th...

Examples

preparation example Construction

[0028] A preparation method of 4-methoxy-2-nitroaniline, the synthetic route is as follows:

[0029] Concrete synthetic steps include:

[0030] 1) Compound (1) N -Benzenesulfonyl-4-methoxyaniline is dissolved in 1,2-dichloroethane, added in pyridine and copper nitrate trihydrate, and reacted when the solution temperature reaches 90°C-115°C N -Benzenesulfonyl-4-methoxy-2-nitroaniline; after the reaction is completed, pour the reaction solution into ice water, adjust the pH = 6, extract 3 times with 1,2-dichloroethane, combine the organic phases, Dry over anhydrous sodium sulfate, filter, wash the filter cake with 1,2-dichloroethane, and remove the solvent under reduced pressure to obtain (2) N - Crude benzenesulfonyl-4-methoxy-2-nitroaniline. Among them, compound (1) N -Benzenesulfonyl-4-methoxyaniline and copper nitrate trihydrate react with a substance ratio of 1: (1-5).

[0031] 2) Compound (2) N Add the crude product of -benzenesulfonyl-4-methoxy-2-nitroaniline to 1,2...

Embodiment 1

[0035] First Synthesis of Compounds (2) N -Benzenesulfonyl-4-methoxy-2-nitroaniline

[0036] Compound (1) N -Benzenesulfonyl-4-methoxyaniline (0.2 mol), pyridine (0.3 mol), and copper nitrate trihydrate (0.3 mol) were added to 200 mL of 1,2-dichloroethane, and after the raw materials were dissolved, Heat the reaction system to 95°C-105°C, generally 100°C, monitor the reaction process with LCMS and HPLC, and process it when the reaction time reaches 12 h. The reaction solution was poured into 1 times the volume of ice water, and the pH was adjusted to pH = 6. A large amount of solids precipitated, extracted three times with 100 mL of 1,2-dichloroethane each time, combined the organic phases, dried over anhydrous sodium sulfate, and filtered. 1,2-Dichloroethane to wash the filter cake. The filtrate was removed in a vacuum to obtain 47.7 g of compound (2) N -Benzenesulfonyl-4-methoxy-2-nitroaniline, yield 74%, HPLC purity 95%.

[0037] compound (2) N The H NMR spectrum of -...

example 2

[0046] First Synthesis of Compounds (2) N -Benzenesulfonyl-4-methoxy-2-nitroaniline

[0047] Compound (1) N -Benzenesulfonyl-4-methoxyaniline (0.2 mol), pyridine (0.3 mol), and copper nitrate trihydrate (0.2 mol) were added to 200 mL of 1,2-dichloroethane, and after the raw materials were dissolved, Heat the reaction system to 95°C-105°C, generally 100°C, monitor the reaction process with LCMS and HPLC, and process it when the reaction time reaches 12 h. Pour the reaction liquid into 1 times the volume of ice water, adjust the pH to PH = 6, a large amount of solids precipitated, extracted three times with 100 mL 1,2-dichloroethane each time, combined the organic phases, dried over anhydrous sodium sulfate, filtered, 1,2-dichloroethane to wash the filter cake. The filtrate was vacuum removed to obtain 41 g of compound (2) N -Benzenesulfonyl-4-methoxy-2-nitroaniline, yield 63%, HPLC purity 94%.

[0048] The second step to synthesize compound (3) 4-methoxy-2-nitroaniline

...