Preparation method of p-benzoquinone dioxime

A technology of p-benzoquinone dioxime and benzoquinone monooxime, which is applied in the fields of oxime preparation, organic chemistry, etc., can solve the problem of reducing the yield and quality of p-benzoquinone dioxime, the appearance of p-benzoquinone dioxime being dark in color, and affecting p-benzoquinone dioxime. quinone monooxime quality and other issues, to achieve the effect of being beneficial to environmental protection, reducing the output of wastewater, and improving yield and quality

Active Publication Date: 2021-12-03
SHANDONG YANGGU HUATAI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Specifically reflected in: 1) the nitrous acid generated by sodium nitrite in case of acid is extremely unstable, and disproportionation and decomposition easily occur when heated, illuminated or in contact with air, producing disproportionation products nitric acid and nitric oxide, and decomposition products dinitrogen trioxide, At the same time, nitrogen trioxide is rapidly decomposed into nitric oxide and nitrogen dioxide, thereby greatly reducing the yield and quality of p-benzoquinonedioxime
2) During the process of nitrosation reaction to

Method used

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preparation example Construction

[0035] The application provides a preparation method of p-benzoquinone dioxime, comprising the following steps in sequence:

[0036] 1) dissolving ethyl nitrite in the organic solvent in the reaction kettle, and mixing uniformly to obtain intermediate liquid A;

[0037] 2) adding phenol to the intermediate liquid A prepared in step 1), and mixing uniformly to obtain intermediate liquid B;

[0038] 3) vacuumize the reactor after step 2) and then fill it with inert gas;

[0039] 4) The concentrated hydrochloric acid is miscible in the organic solvent, and after mixing uniformly, a mixed solution of hydrogen chloride and the organic solvent is obtained;

[0040] 5) Nitrosation reaction: Add the mixed solution of hydrogen chloride and organic solvent prepared in step 4) dropwise to the intermediate liquid B in the reactor, and ethyl nitrite, phenol and hydrogen chloride react chemically in an inert gas atmosphere to form P-benzoquinone monoxime, after completion, intermediate li...

Embodiment 1

[0062] A preparation method of p-benzoquinone dioxime, comprising the following steps carried out in sequence:

[0063] 1) Cool the reactor to 0°C-5°C, dissolve 39.38g of ethyl nitrite in 157.52g of absolute ethanol, mix well to obtain intermediate liquid A, and slowly add intermediate liquid A into the cooled reactor;

[0064] 2) Add 47g of phenol to the intermediate liquid A prepared in step 1), and mix uniformly to obtain intermediate liquid B;

[0065] 3) vacuumize the reactor after step 2) and then fill it with inert gas;

[0066] In step 3), the inert gas is nitrogen, so as to isolate the air and suppress the decomposition of ethyl nitrite;

[0067] 4) Dissolve 48.02g of concentrated hydrochloric acid with a mass fraction of 36% to 38% in 72.03g of absolute ethanol, and mix well to obtain an ethanol solution of hydrogen chloride;

[0068] 5) Nitrosation reaction: when the intermediate liquid B in the reactor is cooled to 0°C, the ethanol solution of hydrogen chloride p...

Embodiment 2

[0079] A preparation method of p-benzoquinone dioxime, comprising the following steps carried out in sequence:

[0080] 1) Cool the reactor to 0°C-5°C, dissolve 39.38g of ethyl nitrite in 157.52g of absolute ethanol, mix well to obtain intermediate liquid A, and slowly add intermediate liquid A into the cooled reactor;

[0081] 2) Add 47g of phenol to the intermediate liquid A prepared in step 1), and mix uniformly to obtain intermediate liquid B;

[0082] 3) vacuumize the reactor after step 2) and then fill it with inert gas;

[0083] In step 3), the inert gas is nitrogen, so as to isolate the air and suppress the decomposition of ethyl nitrite;

[0084] 4) Dissolve 96.05g of concentrated hydrochloric acid with a mass fraction of 36% to 38% in 144.08g of absolute ethanol, and mix well to obtain an ethanol solution of hydrogen chloride;

[0085] 5) Nitrosation reaction: when the intermediate liquid B in the reactor is cooled to 0°C, the ethanol solution of hydrogen chloride ...

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PUM

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Abstract

The invention provides a preparation method of p-benzoquinone dioxime, which comprises the following steps: carrying out nitrosation reaction on ethyl nitrite and phenol under the action of an acidic reaction accelerator to generate an intermediate p-benzoquinone monooxime and a byproduct ethanol, and directly carrying out oximation reaction on the intermediate p-benzoquinone monooxime and hydroxylamine hydrochloride to generate p-benzoquinone dioxime, wherein the whole reaction process is completed in an organic solvent; the discharge of production wastewater is reduced, and the requirement of green production is met; a byproduct ethanol obtained by nitrosation reaction can be finally distilled and recycled together with an organic solvent, so that the utilization rate of raw materials is increased; in the whole synthesis process, an inert gas is adopted to isolate air, so that disproportionation and decomposition of ethyl nitrite and oxidation of an intermediate p-benzoquinone monooxime are avoided, side reactions are reduced, the reaction conversion rate is improved, the yield and purity of p-benzoquinone dioxime are further improved, the yield is 85.0-95.0%, the purity is greater than or equal to 99.0 wt%, and the melting point is 250-255 DEG C.

Description

technical field [0001] The invention relates to the technical field of synthesis and preparation of p-benzoquinone dioxime, in particular to a preparation method of p-benzoquinone dioxime. Background technique [0002] P-benzoquinone dioxime is a crosslinking agent with excellent performance. It has the characteristics of easy dispersion in the rubber compound, fast vulcanization speed, high elongation strength of vulcanized rubber, heat resistance, weather resistance, ozone resistance, and good electrical insulation performance. Widely used in the rubber industry. P-benzoquinone dioxime can be used as a polymerization inhibitor of acrylic acid, which can improve the thermal resistance of polyester fiber tire cord. Regulators, organic monomer stabilizers, self-vulcanizing adhesives, and activating effects on oxidants. P-benzoquinone dioxime is especially suitable for butyl rubber, natural rubber, ethylene-propylene rubber, styrene-butadiene rubber and polysulfide rubber wi...

Claims

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Application Information

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IPC IPC(8): C07C251/46C07C249/06C07C249/08C07C249/14
CPCC07C249/06C07C249/08C07C249/14C07C251/46
Inventor 马德龙吕寻伟于磊韩涛张广振吴彩英
Owner SHANDONG YANGGU HUATAI CHEM
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