Preparation method of 2,6-dihydroxytoluene

A technology of dihydroxytoluene and diaminotoluene, applied in 2 fields, can solve the problems of short service life and large investment, and achieve the effect of avoiding the interference of acid liquid, high quality, avoiding the use of high-pressure equipment and corrosion-resistant materials

Active Publication Date: 2013-09-18
常熟市联创化学有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The study found that method (5) is the most promising path from the perspective of the simplicity of the process and economic cost. Nanjing University of Science and Technology also made considerable research on the second step of the path (Du Binbin 20

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  • Preparation method of 2,6-dihydroxytoluene
  • Preparation method of 2,6-dihydroxytoluene
  • Preparation method of 2,6-dihydroxytoluene

Examples

Experimental program
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Effect test

Embodiment 1

[0063] Such as figure 1 As shown, a 10cm high ceramic ring filler is filled at the bottom of the fixed bed tubular stainless steel reactor (inner diameter 3cm, length 1m), and then a 10g solid acid catalyst is filled (the solid acid catalyst is made of SO 4 2- / ZrO 2 A composite solid acid catalyst composed of solid acid and HZSM-5 molecular sieve, the HZSM-5 silicon-aluminum ratio is 20), and the upper part of the composite solid acid catalyst is filled with a 20cm high ceramic ring filler.

[0064] Turn on the power, set the internal temperature of the fixed bed reactor at 360°C, set the internal temperature of the steam heater (stainless steel tube, inner diameter 3cm, length 50cm) at 320°C, and start the peristaltic pump (BT1-100E, flow 0.07~98ml / min), input the deionized water into the steam heater, control the flow rate of deionized water to be 10ml / min, the water vapor is pumped in from the upper inlet of the fixed bed reactor, and exported from the lower end of the f...

Embodiment 2

[0069] On the basis of Example 1, only the loading amount of the composite solid acid catalyst was changed to 1 gram, the silicon-aluminum ratio of HZSM-5 was 25, and the temperature was raised to 150°C when 2,6-diaminotoluene was heated and melted. Other technological processes and parameters The results are shown in Table 1.

Embodiment 3

[0071] On the basis of Example 1, only change the loading amount of the composite solid acid catalyst to 2 grams, the HZSM-5 silicon-aluminum ratio is 30, 2,6-diaminotoluene is heated to 200 ° C when it is heated and melted, other process flow and parameters The results are shown in Table 1.

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Abstract

The invention discloses a preparation method of 2,6-dihydroxytoluene. The preparation method comprises the following steps of: by taking the 2,6-dihydroxytoluene as an initial raw material; and under the effects of a composite tube solid acid catalyst, preparing the 2,6-dihydroxytoluene through high-temperature steam hydrolysis, wherein the liquefied 2,6-dihydroxytoluene and deionized water are fed into a fixed bed reactor according to a flow ratio of (1:1.5)-(1:10), and the mixed materials are subjected to a hydrolysis reaction through the effect of the solid acid catalyst filled in the fixed bed reactor at high temperature. By utilizing the preparation method, liquid acid with large environment pollution is avoided, at the same time, high-temperature equipment and acid corrosion resisting materials are not used, so that the acid corrosion problem of the equipment in the conventional method is overcome, the environment pollution is reduced, and the economic cost is lowered; moreover the process is simple, the product purity and the yield achieve a good level, the purity of the prepared 2,6-dihydroxytoluene is more than 99% under the optimal condition, and the yield can be 95%.

Description

technical field [0001] The invention relates to the field of fine organic synthesis, in particular to a preparation method of 2,6-dihydroxytoluene. Background technique [0002] 2,6-Dihydroxytoluene can be used in dyestuffs, medicine, pesticides and many other fields, especially as an important component of hair dyes, and is widely used. The currently reported synthesis methods of 2,6-dihydroxytoluene mainly include the following 5 methods, which are specifically discussed in relevant literature (Wu Yonghong et al., Research Progress in the Synthesis of 2-Methyl Resorcinol. Chemical Engineering and Equipment. 2008 .Second Issue; Chen Qiang et al., Preparation of 2-Methyl Resorcinol. Modern Pesticides. Vol.40No.4; Sun Hongtao et al. Preparation of 2-methylresorcinol. Dyes and dyeing Vol.41No.5; 2 Liu Xuelin et al. Synthesis of 2,6-dihydroxytoluene. Applied Chemistry. Vol.21No. 10). [0003] (1) Taking p-toluic acid as starting material: [0004] [0005] This route nee...

Claims

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Application Information

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IPC IPC(8): C07C39/08C07C37/05B01J29/40B01J29/46
Inventor 陈华
Owner 常熟市联创化学有限公司
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