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Preparation method of 3, 4-dihydroxybenzonitrile

A technology of hydroxybenzonitrile and dimethylformamide, which is applied in the field of preparation of 3,4-dihydroxybenzonitrile, can solve the problems of being unsuitable for industrial production, cumbersome methods, difficult source of raw materials, etc., so as to shorten the production cycle , The process is simple and the effect of simplifying the process

Active Publication Date: 2017-09-01
常州佳德医药科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] But above-mentioned method, or involve using highly poisonous drug as reaction catalyst, or raw material source is difficult, or method is more loaded down with trivial details, in a word above-mentioned method is all unsuitable for suitability for industrialized production

Method used

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  • Preparation method of 3, 4-dihydroxybenzonitrile
  • Preparation method of 3, 4-dihydroxybenzonitrile
  • Preparation method of 3, 4-dihydroxybenzonitrile

Examples

Experimental program
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Effect test

Embodiment 1

[0034] Embodiment 1: preparation of vanilla nitrile:

[0035]In a 500ml four-neck flask, add 152.0g vanillin, 125.1g hydroxylamine hydrochloride, and 304ml N,N-dimethylformamide in sequence, stir and mix; heat the oil bath slowly until the inner temperature is about 50°C, and keep the reaction 4 hours; heat slightly, the internal temperature rises to 110°C, and then keep warm for 2 hours; after the reaction is completed, slowly pour the reaction mixture into 1000ml of normal water, stir and crystallize until complete; filter, dry, and get off-white crystalline powder The dry product of vanillin nitrile is 141.69g, yield: 95.1%, melting point: 87.5~88.0°C, purity: 99.30%.

Embodiment 2

[0036] Embodiment 2: preparation of vanilla nitrile

[0037] According to the method of Example 1, 152.0 g of vanillin, 104.25 g of hydroxylamine hydrochloride, and 228 ml of dimethyl sulfoxide were mixed, and the internal temperature was 60 ° C, and the reaction was kept for 4 hours; the inner temperature was raised to 120 ° C, and the reaction was kept for 2 hours; After the reaction is over, the reaction mixture is slowly poured into 1000ml of normal water, stirred and crystallized until complete; filtered and dried to obtain 129.01g of vanilla nitrile dry product in the form of off-white crystalline powder, yield: 86.5%, melting point: 85.5~ 86.0°C, purity: 98.5%.

Embodiment 3

[0038] Embodiment 3: 3,4-dihydroxybenzonitrile preparation

[0039] In a 1000ml four-neck flask, add 120g of vanillin nitrile and 300ml of N,N-dimethylformamide prepared in Example-1 in sequence, stir and mix until the solid dissolves; under cooling, slowly add 145.15g of anhydrous aluminum trichloride, At the same time, when the internal temperature naturally rises to 90°C, the water bath controls the internal temperature to not exceed 120°C to finish adding anhydrous aluminum trichloride; The solution was added to dilute hydrochloric acid and hydrolyzed; the toluene was extracted several times, and the water layer was discarded; the toluene layer was washed with normal water, concentrated under reduced pressure, and the residue was recrystallized with dilute alcohol aqueous solution to obtain a white crystalline solid, which was dried in vacuo to obtain a 95.62 g of 3,4-dihydroxybenzonitrile in the form of white crystalline solid powder, yield: 87.95%, melting point: 155.5-1...

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Abstract

The invention discloses a preparation method of 3, 4-dihydroxybenzonitrile. The method comprises the following steps: taking vanillin as a starting material, enabling vanillin to react with hydroxylamine hydrochloride in a polar solvent at low temperature, and then ensuring that vanillin reacts with hydroxylamine hydrochloride at 50 to 120 DEG C, so as to prepare high-purity Chinese cymbidium nitrile; performing elimination to remove methyl with Lewis acid without separation, so as to obtain high-purity 3, 4-dioxybenzene nitrile in a high yield, with the purity reaching up to 99.0 percent. The method has the advantages that the source of raw materials is wide, the technical process is simple, and pilot scale test shows that 3, 4-dihydroxybenzonitrile is easy for industrial production.

Description

technical field [0001] The invention relates to a preparation method of 3,4-dihydroxybenzonitrile, in particular to a method for producing 3,4-dihydroxybenzonitrile from vanillin (3-hydroxy-4-methoxybenzaldehyde). Background technique [0002] 3,4-Dihydroxybenzonitrile is widely used in pesticides, medicines, dyes and other industries. 3,4-dihydroxybenzonitrile is mainly used for the synthesis of compounds containing thiazole, 2-oxazoline, imidazole, triazole and benzopyrimidine structures, which are important pharmaceutical and pesticide intermediates, especially the synthetic quinazole Phenyl compounds are important anticancer drugs. In addition, in recent years, 3,4-dihydroxybenzonitrile has also begun to be used in the synthesis of photosensitive materials. [0003] The preparation method of 3,4-dihydroxybenzonitrile, the earlier reports all take 3,4-dihydroxybenzaldehyde as the starting material, through oximation and high temperature dehydration, to obtain 3,4-dihydr...

Claims

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Application Information

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IPC IPC(8): C07C253/30C07C255/53
CPCC07C249/08C07C253/00C07C253/30C07C255/53C07C255/54C07C251/48
Inventor 叶还青叶俊
Owner 常州佳德医药科技有限公司
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