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A kind of method for preparing 4,6-diaminoresorcinol hydrochloride by resorcinol one-pot method

A technology for diaminoresorcinol hydrochloride and resorcinol, which is applied in the field of preparing 4,6-diaminoresorcinol hydrochloride, can solve the problems of numerous steps, 4,6-diaminom-phenylene Diphenol hydrochloride is difficult to prepare and other problems, to achieve the effect of simple steps, avoiding the generation of nitro-substituted compounds, and simplifying the reaction steps

Active Publication Date: 2020-07-28
YANGTZE NORMAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above-mentioned deficiencies in the prior art, the present invention investigates the similarities between the resorcinol acylation reaction and oximation, rearrangement and other reactions through a series of experiments, and designs and develops a suitable one that can be used as both acylation reaction and As the same catalyst and solvent for oximation and Beckmann rearrangement reactions, the purpose is to directly prepare the target product of 4,6-diaminoresorcinol hydrochloride from resorcinol in one step, and solve the problem of existing preparation of 4,6 -The problem of numerous steps in the method of diaminoresorcinol hydrochloride, while fundamentally solving the problem of difficult preparation of 4,6-diaminoresorcinol hydrochloride

Method used

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  • A kind of method for preparing 4,6-diaminoresorcinol hydrochloride by resorcinol one-pot method
  • A kind of method for preparing 4,6-diaminoresorcinol hydrochloride by resorcinol one-pot method
  • A kind of method for preparing 4,6-diaminoresorcinol hydrochloride by resorcinol one-pot method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] One-pot preparation of 4,6-diaminom-benzene at 100°C and the molar ratio of phosphorus pentoxide / methanesulfonic acid / hydroxylamine hydrochloride / acetic acid / resorcinol at 0 / 4 / 2 / 2 / 1 Diphenol hydrochloride.

[0025] Weigh resorcinol (5.50g) and acetic acid (6.00g) into a 100 mL three-neck flask, add 13mL (0.2mol) methanesulfonic acid, stir to dissolve, raise the temperature to 100°C, and react for 2 hours. Then gradually add hydroxylamine hydrochloride (7.00g) to it, then continue to react for 4 hours, then add hydrochloric acid (6mol / L, 40 mL) to it, continue to stir at 100°C, react for 2 hours, cool down, crystals are precipitated, and suction filtered , hydrochloric acid washing, ethanol washing, and vacuum drying to obtain 4,6-diaminoresorcinol hydrochloride with a yield of 5.0%.

Embodiment 2

[0027] One-pot preparation of 4,6-diaminom-benzene at 100°C and the molar ratio of phosphorus pentoxide / methanesulfonic acid / hydroxylamine hydrochloride / acetic acid / resorcinol at 0.30 / 2 / 2 / 2 / 1 Diphenol hydrochloride.

[0028] Weigh resorcinol (5.50g), P 2 o 5 (2.15g), acetic acid (6.00g) in a 100 mL three-necked flask, and add 6.5mL (0.1mol) methanesulfonic acid, stir to dissolve, raise the temperature to 120°C, and react for 2 hours. Then gradually add hydroxylamine hydrochloride (7.00g) to it, then continue to react for 4 hours, then add hydrochloric acid (6mol / L, 40 mL) to it, continue to stir at 100°C, react for 2 hours, cool down, crystals are precipitated, and suction filtered , hydrochloric acid washing, ethanol washing, and vacuum drying to obtain 4,6-diaminoresorcinol hydrochloride with a yield of 35%.

Embodiment 3~21

[0030] The difference between embodiment 3~21 and embodiment 1 mainly lies in the molar ratio difference of phosphorus pentoxide, methanesulfonic acid, hydroxylamine hydrochloride, acetic acid, resorcinol (resorcinol is 5.5g), and step (1 ), the reaction time and reaction temperature are different, and other conditions are the same as in Example 1, see Table 1 for details, wherein the acylating reagent used in Example 20 is acetic anhydride.

[0031] Table 1 Molar ratios, reaction conditions and yields of each component in Examples 1 to 21

[0032] Example temperature / ℃ P 2 o 5

Methanesulfonic acid Acylation reagent Resorcinol Hydroxylamine: an acylating reagent time / h Yield / % 1 100 0 4 2 1 1:1 2 5 2 100 0.30 2 2 1 1:1 2 35 3 100 0.70 4 3 1 1.5:1 3 65 4 100 1.50 8 5 1 2:1 5 68 5 120 0.30 2 3 1 1.5:1 5 47 6 120 0.70 4 5 1 2:1 2 92.5 7 120 1.50 8 2 1 1:1 3 90 8 ...

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Abstract

The invention discloses a method for preparing 4,6-diamino resorcinol hydrochloride by a resorcinol one-pot method. The method comprises the following steps of (1) uniformly mixing and dissolving methanesulfonic acid, an acylation reagent and resorcinol according to a mole ratio of (2 to 8) to (2 to 5) to 1; performing reaction for 1 to 3h at 80 to 140 DEG C, wherein the acylation reagent is acetic acid or acetic anhydride; (2) after the reaction in the step (1) is completed, adding hydroxylamine with the mole ratio of the acylation reagent to the hydroxylamine being (1 to 2) to 1; continuously performing reaction for 2 to 5h; (3) after the reaction in the step (2) is completed, performing amide hydrolysis and hydrochlorination reaction; performing cooling and crystallization on products to obtain the 4,6-diamino resorcinol hydrochloride. Through the reaction steps of acylation, oximation, rearrangement, hydrolysis, hydrochlorination and the like, the 4,6-diamino resorcinol hydrochloride is prepared by the one-pot method through the proper communicated reagent; a large number of purification processes in the middle process are avoided; the reaction steps are simplified; the occurrence of side reactions is reduced; the production efficiency is greatly improved; the cost is reduced.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing 4,6-diaminoresorcinol hydrochloride by a one-pot method of resorcinol. Background technique [0002] Poly-p-phenylene-benzobisoxazole fiber (Poly-p-phenylene-benzobisoxazole, referred to as PBO), known as the 21st century super fiber. The high temperature resistance of PBO fiber is the highest among organic materials; its tensile strength and modulus are much higher than those of carbon fibers, and it is the fiber material with the largest tensile strength and modulus so far; at the same time, its flame resistance is also The best among organic materials; it also has the characteristics of corrosion resistance, low density, etc. Due to this excellent performance characteristic, it has important applications in key and special fields such as national defense and military industry, aerospace, fire prevention and fire protection. However, at pres...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C213/02C07C215/80
CPCC07C45/455C07C213/02C07C249/08C07C215/80C07C251/48C07C49/825
Inventor 陈凤贵
Owner YANGTZE NORMAL UNIVERSITY
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