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Synthesis method of 2,6-dihydroxytoluene

A technology of dihydroxytoluene and a synthesis method, which is applied in the field of synthesis of 2,6-dihydroxytoluene, can solve the problems of being unsuitable for large-scale industrial production, high equipment requirements, and many side reactions, and achieves convenient industrial production and less three wastes. , the effect of easy operation

Pending Publication Date: 2021-11-26
NANJING JIEYUN PHARMA TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The first step of the route is diazotization reaction, which causes serious pollution and many wastes
The second step reaction requires the use of expensive rare-earth catalysts, and the cost is high
High requirements on equipment, many side reactions, not suitable for large-scale industrial production

Method used

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

Examples

Experimental program
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Effect test

Embodiment 1

[0042] 2,6-dichlorotoluene into the 1L autoclave, 161 g, sodium hydroxide 120g, cuprous chloride 5g, sodium dodecyl sulfate 1.6g, water 480g. Sealed and heated to 120 deg.] C with stirring for 8 h, TLC monitoring until starting material is completely converted (eluent petroleum ether: ethyl acetate = 10: 1). Cooling to 40 ~ 50 ℃, filtered off with suction. The filter cake was placed in an oven at 80 ~ 100 ℃ dried to constant weight, as the next batch of feed the catalyst applied.

[0043] The filtrate is an aqueous solution of sodium 2,6-dihydroxy toluene, adjusting pH value with concentrated hydrochloric acid 3 ~ 4,0 ~ 10 ℃ stirred for 2 hours, filtered off with suction. To give a yellow solid which was purified by distillation to give white crystals of water vapor, i.e., 2,6-dihydroxy toluene finished 87 g, HPLC purity> 99%, yield 75%.

Embodiment 2

[0045] 2,6-dichlorotoluene into the 1L autoclave, 161 g, 168g of potassium hydroxide, cuprous chloride 5g, diatomaceous earth 3g, water 480g. Sealed and heated to 100 deg.] C with stirring for 6 h, TLC monitoring until starting material is completely converted (eluent petroleum ether: ethyl acetate = 10: 1). Cooling to 40 ~ 50 ℃, filtered off with suction. The filter cake was dried, as the next batch of feed the catalyst applied.

[0046] The filtrate is an aqueous solution of potassium 2,6-dihydroxy toluene, adjusting pH value with concentrated hydrochloric acid 3 ~ 4,0 ~ 10 ℃ stirred for 2 hours, filtered off with suction. To give a yellow solid which was purified by distillation to give 2,6-dihydroxy toluene vapor finished 93 g, HPLC purity> 99%, yield 75%.

Embodiment 3

[0048] 2,6-dibromo toluene into 2L autoclave 250 grams of sodium hydroxide 200g, cuprous bromide 10g, montmorillonite 5g, water 700g. Sealed was heated to 140 deg.] C to react for 7 h, TLC monitoring until starting material is completely converted (eluent petroleum ether: ethyl acetate = 10: 1). Cooling to 40 ~ 50 ℃, filtered off with suction. The filter cake was dried, as the next batch of feed the catalyst applied.

[0049] The filtrate is an aqueous solution of sodium 2,6-dihydroxy toluene, adjusting pH value with concentrated hydrochloric acid 3 ~ 4,0 ~ 10 ℃ stirred for 2 hours, filtered off with suction to give crude 2,6-dihydroxy toluene, 74g toluene and recrystallized to give the finished product , HPLC purity> 99%, yield 60%.

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Abstract

The invention belongs to the technical field of organic chemical synthesis, and particularly relates to a synthesis method of 2,6-dihydroxytoluene. The synthesis process comprises the following steps: S1, mixing 2,6-dihalogenated toluene, alkali, a heavy metal salt catalyst and an adsorbent, and heating and hydrolyzing to obtain a salt solution of 2,6-dihydroxytoluene; S2, adjusting the pH value of the 2,6-dihydroxytoluene salt solution obtained in the previous step to be weakly acidic by using an acid, separating a separated solid, and purifying to obtain a pure product of 2,6-dihydroxytoluene. The adopted main raw materials, such as 2,6-dichlorotoluene, cuprous chloride, sodium dodecyl sulfate and potassium hydroxide, are common chemical raw materials in the market, and are cheap, easy to obtain and wide in source; the synthesis route is short, steps are few, operation is simple, and production cost is greatly saved; reaction conditions are mild, and industrial production is facilitated; the process route is less in three wastes, the catalyst and the adsorbent can be repeatedly used, emission of the three wastes is further reduced, and the method is environment-friendly; the yield of the whole route is high, and the cost advantage is remarkable.

Description

Technical field [0001] The present invention belongs to the field of synthetic organic chemistry techniques, particularly directed to a process for the synthesis of 2,6-dihydroxy toluene. Background technique [0002] 2,6-dihydroxy-toluene is an important chemical intermediate, is widely used in the field of synthetic resin, dye, medicine, pesticides, dyes and other photosensitive materials. In the medical field, this intermediate as a raw material can be shorter Cihu Pigment spines. In the field of pesticides, toluene, 2,6-dihydroxy salicylic acid as an intermediate in the synthesis of double-pyrimidine herbicides. In the field of materials, 2,6-dihydroxy toluene feedstock may be synthesized as a series of porphyrin porphine compounds, such compounds are widely used in the polymer materials and chemical catalysis. [0003] Currently, the main method for the synthesis of 2,6-dihydroxy toluene are the following: [0004] 1, 3-chloro-2-methylaniline as a starting material, to give ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/64C07C37/055C07C39/235C07C39/08
CPCC07C37/64C07C37/055C07C39/235C07C39/08
Inventor 舒恺邹远林华阳黄友元史丹丹刘足和方靖刘郝敏吴晓东
Owner NANJING JIEYUN PHARMA TECH CO LTD