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Preparation method of 4,6-diamino resorcinol hydrochloride

A technology of diaminoresorcinol hydrochloride and diacetylresorcinol, which is applied in the field of organic chemical synthesis, can solve problems such as increased production costs, high costs, and environmental pollution, and achieve reduced reaction costs and thorough reactions , the effect of simple operation

Active Publication Date: 2020-05-15
ASTATECH CHENGDU BIOPHARM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The chemical synthesis of 4,6-diaminoresorcinol was initially successfully developed by Dow Chemical Company in the United States. It was synthesized with trichlorobenzene as the starting material, and the yield was relatively high, which played a great role in the industrial production of PBO fibers. , but the preparation raw materials are not easy to obtain and the cost is high
But this method adopts polyphosphoric acid (abbreviated as PPA) in the last step of rearrangement in the process of preparing 4,6-diaminoresorcinol hydrochloride, which will produce a large amount of phosphorus-containing wastewater, pollute the environment, and cost three wastes at the same time is also high, so that the overall production cost increases

Method used

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  • Preparation method of 4,6-diamino resorcinol hydrochloride
  • Preparation method of 4,6-diamino resorcinol hydrochloride
  • Preparation method of 4,6-diamino resorcinol hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Under nitrogen protection and stirring conditions, add 1000.00g of acetic acid, 286.25g of acetic anhydride, and 220.00g of intermediate oxime to a 3000mL three-necked flask in sequence. After the addition is complete, raise the temperature to 78°C and keep it warm for 3 hours;

[0031] After the reaction, distill under reduced pressure at 60°C to recover the solvent and residue, add 5.4g of stannous chloride and 550.00g of concentrated hydrochloric acid to the residue, heat to 100°C and reflux for 2 hours, a large amount of khaki solid precipitates , the temperature of the reaction system was lowered to 5° C., stirred for 2 hours to crystallize, suction filtered, washed with hydrochloric acid, and the filter cake was vacuum-dried at 45° C. to obtain crude 4,6-diaminoresorcinol hydrochloride.

[0032] The yield of the crude product 4,6-diaminoresorcinol hydrochloride was 163.7g, the yield was 80.0%, and the HPLC purity was 90.5%. The crude product was recrystallized wit...

Embodiment 2

[0034]Under nitrogen protection and stirring conditions, add 1300.00g of acetic acid, 312.25g of acetic anhydride, and 220.00g of intermediate oxime to a 3000mL three-necked flask in sequence. After the addition is complete, heat up to 90°C and keep it warm for 4 hours;

[0035] After the reaction, distill under reduced pressure at 60°C to recover the solvent and residue, add 6.5g of stannous chloride and 600.00g of concentrated hydrochloric acid to the residue, heat to 90°C and reflux for 3 hours, a large amount of khaki solids precipitate , the temperature of the reaction system was lowered to 5° C., stirred for 2 hours to crystallize, suction filtered, washed with hydrochloric acid, and the filter cake was vacuum-dried at 45° C. to obtain crude 4,6-diaminoresorcinol hydrochloride.

[0036] The yield of the crude product 4,6-diaminoresorcinol hydrochloride was 171.5 g, the crude product yield was 83.8%, and the HPLC purity was 91.5%. The crude product was recrystallized with...

Embodiment 3

[0038] Under the condition of nitrogen protection and stirring, add 1500.00g of acetic acid, 350.11g of acetic anhydride, and 220.00g of intermediate oxime to a 3000mL three-necked flask in sequence. After the addition is complete, raise the temperature to 95°C and keep it warm for 4 hours;

[0039] After the reaction, distill under reduced pressure at 60°C to recover the solvent and residue, add 7.5g of stannous chloride and 600.00g of concentrated hydrochloric acid to the residue, heat to 90°C and reflux for 3 hours, a large amount of khaki solids precipitate , the temperature of the reaction system was lowered to 5° C., stirred for 2 hours to crystallize, suction filtered, washed with hydrochloric acid, and the filter cake was vacuum-dried at 45° C. to obtain crude 4,6-diaminoresorcinol hydrochloride.

[0040] The yield of crude product 4,6-diaminoresorcinol hydrochloride was 182.3g, the crude product yield was 89.2%, and the HPLC purity was 94.3%. The crude product was rec...

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Abstract

The invention relates to a preparation method of 4,6-diamino resorcinol hydrochloride, and belongs to the field of organic chemical synthesis. The preparation method of the 4,6-diamino resorcinol hydrochloride comprises the following steps: taking Bronsted acid and acetic anhydride as a new dioxime Beckmann rearrangement reaction system, and carrying out heating reaction and reduced pressure distillation to obtain residues and a recovered solvent; heating the residues by using concentrated hydrochloric acid and SnCl2, and carrying out a reflux reaction to realize hydrolysis operation; and carrying out cooling, stirring crystallization, suction filtration, hydrochloric acid washing and vacuum drying to obtain the 4,6-diamino resorcinol hydrochloride. The method has the advantages of simpleprocess steps, easiness in obtaining of the Bronsted acid and the acetic anhydride, realization of repeated utilization of excessive Bronsted acid and acetic anhydride, and acetic acid generated in the reaction process are recycled through reduced pressure distillation, avoiding of environmental pollution caused by generation of a large amount of phosphorus-containing wastewater, and effective reduction of the production cost.

Description

technical field [0001] The invention belongs to the field of organic chemical synthesis, and in particular relates to a preparation method of 4,6-diaminoresorcinol hydrochloride. Background technique [0002] Poly-p-phenylene benzobisoxazole fiber (PBO for short) is known as the super fiber of the 21st century. It was first developed by the United States in the 1980s for the development of the aerospace industry. Later, the patent was transferred to Japan's Toyobo Corporation and industrialized. So far, Toyobo is still the only company in the world with this technology. The high temperature resistance of PBO fiber is the highest among organic materials at present, and its tensile strength and modulus are much higher than those of carbon fibers. The best; it also has corrosion resistance, low density and other characteristics. Due to such excellent performance characteristics, PBO fiber has extremely important applications in key and special fields such as national defense...

Claims

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Application Information

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IPC IPC(8): C07C213/02C07C215/80
CPCC07C213/02C07C215/80
Inventor 查家龙丁刚何紫权胡志鹏雷皇叔郭鹏李洵栾家坤
Owner ASTATECH CHENGDU BIOPHARM CORP
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