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Synthetic process of 4,6-dinitroresorcinol

A technique for the synthesis of dinitroresorcinol, which is applied in the field of synthesis of 4,6-dinitroresorcinol, can solve problems such as selectivity needs to be improved, achieve shortened production cycle, increase yield, The effect of reducing production costs

Active Publication Date: 2018-04-13
EAST CHINA UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In this process, the yield of DNRS hydrolysis to prepare DNR step is about 68%, but because the yield of nitration reaction step is only about 50%, the total yield of sulfonation, nitration reaction and hydrolysis reaction is only about 35%, obviously lower than The yield of DNR synthesized by the trisulfonation method is produced by using the traditional batch process, and the selectivity of the whole reaction control step-nitration reaction needs to be improved, so the process needs further improvement

Method used

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  • Synthetic process of 4,6-dinitroresorcinol
  • Synthetic process of 4,6-dinitroresorcinol

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] The synthetic technique of embodiment 1,4,6-dinitroresorcinol

[0040] (1) Resorcinol was dissolved in dimethyl sulfoxide to prepare an RS-DMSO raw material solution. The concentration of resorcinol was 4.26 mol / L, which was 40.91% in mass percent conversion.

[0041](2) Divide 20% oleum into a plurality of branch streams, distribute evenly from the periphery of the micro-mixer, and pump it into the micro-channel of the cross-shaped micro-mixer, and the RS-DMSO raw material solution flows along the center of the micro-mixer The pump is pumped into the cross cross micro-mixer, and after the two are mixed, they are mixed through a packing mixer (diameter 5mm) filled with quartz sand random packing to obtain a mixed solution; the mixed solution then enters a pipe with a diameter of 3 mm The sulfonation reaction is carried out in the reactor. Real-time detection of the mass flow rate of RS-DMSO raw material solution during the reaction to control the free SO in fuming sulf...

Embodiment 2

[0047] The synthetic technique of embodiment 2,4,6-dinitroresorcinol

[0048] Other conditions were the same as in Example 1, except that the temperature of the water bath was controlled to be 10° C. for the nitration reaction, and the obtained solid product and filtrate were obtained. By HPLC analysis nitration product feed liquid and solid product and filtrate composition, the results are as follows:

[0049] Among the nitration products at the outlet of the pipeline reactor, the selectivity of the main product 2-sulfonic acid group-4,6-dinitroresorcinol (DNRS) was 85%, and the selectivity of 2,4-disulfonic acid group-6- Nitroresorcinol (DSRN) has a selectivity of 15%, while 2,4,6-trinitroresorcinol (TNR) is produced during pyrohydrolysis.

[0050] The total yield of the main product DNR obtained after sulfonation, nitration and hydrolysis reactions was 62%, the total yield of TNR was 9%, and the total yield of DSRN and SRN was 29%.

Embodiment 3

[0051] The synthetic technique of embodiment 3,4,6-dinitroresorcinol

[0052] Step (1) is identical with embodiment 1.

[0053] (2) Evenly distribute 26% oleum into the valve-controlled mixer from the periphery, and the RS-DMSO raw material liquid enters the valve-controlled mixer from the inside, and is strengthened by a static mixer (model: SK-5 / 10) Mix to obtain a mixed liquid; the mixed liquid then enters a pipe reactor with a diameter of 10 mm (diameter 10 mm) for sulfonation reaction. Real-time detection of the mass flow rate of RS-DMSO raw material solution during the reaction to control the free SO in fuming sulfuric acid 3 The molar ratio with resorcinol is 7:1. Both the static mixer and the pipeline reactor are temperature-controlled by a water bath, and the temperature of the water bath is controlled to be 91° C., and the residence time is controlled to be 340 s to obtain a sulfonated product liquid.

[0054] (3) Evenly distribute the sulfonated product liquid in...

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Abstract

The invention provides a synthesis process of 4, 6-dinitroresorcinol. Sulfonation reaction, nitration reaction and hydrolysis reaction are carried out on raw materials in order. Specifically, sulfonation reaction and nitration reaction are both carried out in a pipe reactor. Before sulfonation reaction, a raw material liquid and a sulfonating reagent respectively enter a micromixer for mixing and are subjected to reinforced mixing by a reinforcing mixer, then the mixture enters the pipe reactor for sulfonation reaction, and the temperatures of the reinforcing mixer and the pipe reactor are controlled by a temperature control device; and before nitration reaction, a sulfonation product liquid and the sulfonating reagent respectively enter a micromixer for mixing and are subjected to reinforced mixing by a reinforcing mixer, then the mixture enters the pipe reactor for nitration reaction, and the temperatures of the micromixer, the reinforcing mixer and the pipe reactor are controlled by the temperature control device. The process provided by the invention can realize rapid material mixing and exact temperature control, has a DNR total yield up to 87%, can realize continuous production, improves production safety, shortens the production cycle, lowers the production cost, and is also friendly to the environment.

Description

technical field [0001] The invention relates to a synthesis process of aromatic dinitro compounds, in particular to a synthesis process of 4,6-dinitroresorcinol. Background technique [0002] Poly-p-phenylenebenzobisoxazole (PBO) fiber is currently the product with the best comprehensive performance among aromatic heterocyclic fibers, and has broad application prospects. 4,6-diaminoresorcinol (DAR), an important intermediate of PBO fiber, can be prepared by hydrogenation reduction of 4,6-dinitroresorcinol (DNR), so the yield and purity of DNR directly determine Whether it is possible to obtain PBO fibers with large output and high performance. There are many synthesis methods of DNR in the prior art, but there are common problems of expensive raw materials, high preparation cost, difficulty in industrial production and serious pollution, which makes the manufacturing cost of PBO fiber remain high, which makes it difficult to popularize and apply. [0003] Chinese patent (A...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C201/12C07C205/23
CPCC07C201/12C07C303/06C07C303/22C07C205/23C07C309/42
Inventor 周兴贵张化良周静红段学志钱刚
Owner EAST CHINA UNIV OF SCI & TECH