Process for preparing 4,6-diamino resorcinol hydrochloride

A technology of diaminoresorcinol hydrochloride and dihydroxybenzene, which is applied in 4 fields, can solve the problems of oxidation of 4,6-diaminoresorcinol and difficult separation of catalysts, and achieve catalyst activity without reduction, The prospect of large-scale industrial production and the effect of high yield

Inactive Publication Date: 2003-10-22
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved in the present invention is to disclose a new preparation method of 4,6-diaminoresorcinol hydrochloride, to overcome the rare metal catalyst existing in the prior art that cannot be recycled economically and the product and Pd In the separation process of / C catalyst, the oxidation of 4,6-diaminoresorcinol and the disadvantages that the catalyst is difficult to separate appear

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Add 15g of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene, 60ml of ethanol, 4g of formic acid, and 1.5g of 5% Pt / C into a 200ml reactor. Will N 2 Introduce air into this sealed reactor for three times, and then use H 2 Replace three times. The reaction temperature is 35°C and the pressure is 1.0Mpa. After the reaction, the reaction feed liquid was cooled to room temperature. through a riser fitted with a filter, with N 2 Pour the reaction liquid into 100ml containing 4g SnCl 2 2H 2 O in 3N dilute hydrochloric acid solution, the Pt / C catalyst remained in the reactor. Ethanol was distilled off under reduced pressure, and 50 ml of chemically pure concentrated hydrochloric acid was added to the distillate, and diaminoresorcinol hydrochloride was precipitated from the light yellow solution. Filter to obtain white filter cake, i.e. 4,6-diaminoresorcinol hydrochloride white crystal, its dry weight is 9.2g (according to 4,6-dinitro-2-chloro-1,3-dihydroxybenzene As a benchmar...

Embodiment 2

[0025] Add 15g of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene, 70ml of propanol, 4g of ammonium acetate, and 2.0g of 3% Pd / C into a 200ml reactor. Will N 2 Introduce air into this sealed reactor for three times, and then use H 2 Replace three times. h 2 The pressure reaches 3Mpa and the temperature reaches 90°C. After the reaction, the reaction feed liquid was cooled to room temperature. through a riser fitted with a filter, with N 2 Pour the reaction liquid into 100ml containing 4g SnCl 2 2H 2 O in 3N dilute hydrochloric acid solution, the Pd / C catalyst remained in the reactor. Propanol was distilled off under reduced pressure, and 50 ml of chemically pure concentrated hydrochloric acid was added to the distillate, and diaminoresorcinol hydrochloride was precipitated from a light yellow solution. Filtrate to obtain white filter cake, i.e. diaminoresorcinol hydrochloride white crystal, its dry weight is 13.2g (according to 4,6-dinitro-2-chloro-1,3-dihydroxybenzene is a ...

Embodiment 3

[0027] Add 15g of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene, 50ml of benzene, 4g of hydrazine hydrate, and 1.5g of 5% Pt / C into a 200ml reactor. Will N 2 Introduce air into this sealed reactor for three times, and then use H 2 Replace three times. h 2 The pressure reaches 0.5Mpa and the temperature reaches 50°C. After the reaction, the reaction feed liquid was cooled to room temperature. through a riser fitted with a filter, with N 2 Pour the reaction liquid into 100ml containing 4gSnCl 2 2H 2 O in 3N dilute hydrochloric acid solution, the Pt / C catalyst remained in the reactor. Benzene was distilled off under reduced pressure, and 50 ml of chemically pure concentrated hydrochloric acid was added to the distillate, and diaminoresorcinol hydrochloride was precipitated from a light yellow solution. Filtrate to obtain white filter cake, i.e. diaminoresorcinol hydrochloride white crystal, its dry weight is 6.6g (according to 4,6-dinitro-2-chloro-1,3-dihydroxybenzene is a b...

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Abstract

The present invention discloses a preparation method of 4,6-diaminoresorcinol hydrochloride, including catalytioc hydrogenation step of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene by using hydrogen in the organic solvent and in the presence of rare metal catalyst at normal pressure or middle pressure and normal temp. or under the condition of heating. Said catalyst is formed from carrier which is stable for organic solvent and rare metal loaded on the carrier, and the rare metal content is 0.1-10 wt% of total weight of said carrier. Said invention not only can continuously make multiple hydrogenation, and activity of said catalyst is not reduced, at the same time, but also can obtain high-yield and high-quality 4,6-diaminoresorbinol hydrochloride.

Description

technical field [0001] The invention relates to a preparation method of 4,6-diaminoresorcinol hydrochloride, which is prepared by catalytic hydrogenation of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene to 4 , 6-diaminoresorcinol hydrochloride. Background technique [0002] 4,6-Diaminoresorcinol hydrochloride is an important structural unit of various macromolecules, especially polybenzoxazoles (cf. Wolf et al., "Macromolecules" 1981, 14:915). [0003] Its structural formula is as follows: [0004] US5399768 and US5371281 and US925358 describe the method for preparing 4,6-diaminoresorcinol through catalytic hydrogenation of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene, an obvious one of said method The disadvantage is that the heterogeneous catalytic hydrogenation of 4,6-dinitro-2-chloro-1,3-dihydroxybenzene in batch hydrogenation over Pd / C catalysts does not enable the economical recycling of expensive rare metal catalysts . At the same time, due to the low stability of 4,6-...

Claims

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Application Information

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IPC IPC(8): C07C213/02C07C215/80
Inventor 王幸宜刘战勇韩哲文李欣欣冯东东王昭
Owner EAST CHINA UNIV OF SCI & TECH
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