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Technology for directly synthesizing acetaminophen from nitrobenzene

A technology of acetaminophen and nitrobenzene, which is applied in the preparation of organic compounds, the preparation of carboxylic acid amides, organic chemistry and other directions, can solve the problems of complex process, large amount of waste liquid in the production process, etc., and achieves high product yield and simplification. Production process, the effect of avoiding the discharge of waste liquid

Inactive Publication Date: 2014-04-16
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, for the synthesis of p-aminophenol reaction process by the hydrogenation of nitrobenzene carried out in sulfuric acid solution, in order to carry out the follow-up acylation process, it is necessary to neutralize the reaction solution with a large amount of ammonia water, resulting in a large amount of waste liquid in the production process. complex

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] In the first step, 0.04 g of zinc sulfate, 0.1 g of Pt / SiO with a Pt loading of 0.1% 2 Catalyst, 2g nitrobenzene, 0.01g hexadecyltrimethylammonium bromide, 0.05g cocatalyst EDTA and 50ml water are put into the autoclave, wherein the zinc ion concentration is 4.9mmol / L;

[0022] In the second step, in the above-mentioned autoclave, with N 2 After replacing the air for 8-12 minutes, heat to 180°C and pass in H 2 , until the hydrogen partial pressure is 1.0MPa, react for 6 hours to convert nitrobenzene into p-aminophenol;

[0023] In the third step, after the reaction of the second step is completed, the reaction solution is filtered while it is hot, and the solid-phase catalyst and the reaction solution are separated;

[0024] In the fourth step, the filtered reaction solution is distilled at 40-100°C under a pressure of 0.05-0.1 MPa to distill off the by-product aniline and part of the water;

[0025] The fifth step is to cool the reaction solution from the aniline se...

Embodiment 2

[0028] In the first step, 0.49 g of zinc nitrate, 0.1 g of Pt / Al with a Pt loading of 0.3% 2 o 3 Catalyst, 2g nitrobenzene, 0.1g cocatalyst EDTA, 0.01g cetyltrimethylammonium bromide and 50ml water are put into autoclave;

[0029] In the second step, in the above-mentioned autoclave, with N 2 After replacing the air for 8 to 12 minutes, heat to 200°C and pass in H 2 , until the partial pressure of hydrogen is 0.1MPa, react for 8 hours to convert nitrobenzene into p-aminophenol;

[0030] In the third step, after the reaction of the second step is completed, the reaction solution is filtered while it is hot, and the solid-phase catalyst and the reaction solution are separated;

[0031] In the fourth step, the filtered reaction solution is distilled at 40-100°C under a pressure of 0.05-0.1 MPa to distill off the by-product aniline and part of the water;

[0032] The fifth step is to cool the reaction solution from the aniline separated in the fourth step to 30-50°C, add the a...

Embodiment 3

[0035] In the first step, 0.01 g of zinc sulfate, 0.3 g of Pt / C catalyst with a Pt loading of 0.01%, 0.1 g of cocatalyst EDTA, 1 g of nitrobenzene, and 0.01 g of hexadecyltrimethyl bromide Ammonium and 50ml water are put into autoclave;

[0036] In the second step, in the above-mentioned autoclave, with N 2 After replacing the air for 8-12 minutes, heat to 80°C and pass in H 2 , until the hydrogen partial pressure is 2.0MPa, react for 5 hours to convert nitrobenzene into p-aminophenol;

[0037] In the third step, after the reaction of the second step is completed, the reaction solution is filtered while it is hot, and the solid-phase catalyst and the reaction solution are separated;

[0038] In the fourth step, the filtered reaction solution is distilled at 40-100°C under a pressure of 0.05-0.1 MPa to distill off the by-product aniline and part of the water;

[0039] The fifth step is to cool the reaction liquid from the aniline separated in the fourth step to 30-50°C, add ...

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Abstract

The invention provides a technology for directly synthesizing acetaminophen from nitrobenzene. The technology comprises the following steps: placing lewis acid metal salt, a supported Pt metal catalyst, a promoter, the nitrobenzene, cetyl trimethyl ammonium bromide and water into a high-pressure reaction kettle; replacing the air by N2; charging H2; reacting for 1 to 10 hours at 80 to 200 DEG C; filtering the reaction liquid in a hot state; cooling the reaction liquid subjected to reduced pressure distillation to reach 30 to 50 DEG C; adding acetic anhydride to react for 0.2 to 1 hour; concentrating and cooling the obtained reaction liquid to separate crystal; and then filtering to obtain the crystal which is the acetaminophen. According to the process, the reaction is carried out in the trace metal salt solution, and the yield of the acetaminophen still can reach more than 70% if the concentration of the metal salt solution is less than 5mmol / L; the pH (Potential Of Hydrogen) value of the solution is not needed to be regulated by ammonia water during the reaction process; and the crystallization mother liquor in which the acetaminophen is separated can be recycled, so that no waste liquid is drained.

Description

technical field [0001] The technical solution of the present invention belongs to the field of organic chemistry, specifically a process for directly synthesizing acetaminophen from nitrobenzene. Background technique [0002] Acetaminophen (APAP for short) is an excellent antipyretic and analgesic drug, and it is also an intermediate for the synthesis of many other drugs. Industrially, acetaminophen is mostly produced by acylation of p-aminophenol with acetic acid or anhydride. According to whether the preparation of p-aminophenol and acetaminophen needs to be carried out independently, it can be divided into one-step method and two-step method. [0003] In the two-step production process, the reduction of raw materials to generate p-aminophenol and the acylation of p-aminophenol to generate acetaminophen are carried out independently. Since p-aminophenol is easily oxidized and discolored during production, transportation and storage, it is When preparing acetaminophen, p-...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C233/25C07C231/02
Inventor 王延吉石苗苗沈建琦王淑芳马丛
Owner HEBEI UNIV OF TECH