Background and Overview
Resorcinol, also known as resorcinol, is a chemical substance used as a chemical raw material. On October 27, 2017, the World Health Organization’s International Agency for Research on Cancer released a preliminary reference list of carcinogens. Resorcinol is included in the list of Class 3 carcinogens.
Apply [1-4]
1. Preparation of m-methoxyphenol
Me-methoxyphenol is the monomethyl ether of resorcinol. It is an important pharmaceutical chemical raw material and can be used in many fields such as plastic antioxidants, bactericides, and photosensitive materials. There are few domestic reports on the preparation method of m-methoxyphenol.
CN201610954300.2 provides a method for preparing m-methoxyphenol from resorcinol that is suitable for industrial production. Includes the following steps:
(1) After resorcinol and phase transfer catalyst are dissolved in a certain solvent, add alkali solution, add methylation reagent dropwise under alkaline conditions, and complete the insulation reaction. Stop when resorcinol <5% reaction;
(2) Adjust the pH of the reaction solution to strong acidity with acid, separate the liquids, extract the aqueous layer with a certain amount of toluene, combine the organic phases, collect the organic phases after washing with water or dilute alkali solution, and use Adjust the pH to strong alkaline with the alkali solution, stir for a period of time, separate the liquids, adjust the pH of the water phase to strong acidity with acid, add toluene to extract after stirring, collect the organic phase, then extract the water layer with toluene, combine the organic phases, and mix at a certain temperature. The toluene in the product and by-product is recovered by rotary evaporation, and a product with HPLC>95.0% is obtained. The invention improves the purity of the product while simplifying the process flow and reducing the reaction conditions, making the product more suitable for mass production.
2. Synthesis of 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine
2,4,6-Tris(2,4-dihydroxyphenyl)-1,3,5-triazine is a new type of highly efficient ultraviolet absorber triazine-5 (chemical name: 2,4 , an important precursor of 6-tris(2-hydroxy-4-n-butoxy)-1,3,5-triazine), is a new variety of ultraviolet absorbers with strong absorption capacity and good antioxidant properties. The raw materials are based in China and have the advantages of low product cost and simple synthesis process. In order to solve the shortcomings in the prior art that the synthesis process cost of 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine is high and the environmental pollution is great, the present invention CN200310109889.9 Provide a high-quality, low-cost chemical synthesis method with little environmental pollution.
The technical solution adopted by the present invention to solve the existing technical problems is: a chemical synthesis method of 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine, The method described uses cyanuric chloride and resorcinol as raw materials, reacts in a haloalkane or aromatic hydrocarbon organic solvent with 1 to 6 carbon atoms and 1 to 4 halogen atoms under the action of a catalyst to generate 2, 4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine is then separated and purified. The catalyst is a Lewis acid or heteropolyacid containing halogen atoms.
The beneficial effects of the chemical synthesis method of 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine according to the present invention are mainly reflected in:
(1) The synthesis reaction is completed in one step, with simple steps and low cost;
(2) The solvent can be recycled and causes little environmental pollution;
(3) Product yield is high and quality is good.
3. Used in the preparation of 2,4,6-triiodoresorcinol
Iodophenol is 2,4,6-Triiodoresorcine, which appears as white fine needle crystals. It was first prepared by the Chemical Drug Research Center of the former Soviet Union and later caused The interest of researchers in many other countries has generated a large amount of research work. Iodine powder has a good inhibitory effect on herpes virus, Microsporum, Candida albicans, Staphylococcus aureus and Corynebacterium diphtheriae, and is a broad-spectrum antiviral drug. Many diseases are often induced by microorganisms and are accompanied by viral and fungal infections, so the therapeutic effect of iodophenol is better than other single-acting drugs. CN201810353401.3 provides a preparation method of 2,4,6-triiodoresorcinol to solve the problem that the synthesis process route of 2,4,6-triiodoresorcinol in the existing technology is complicated and requires the addition of strong alkali Or problems such as lower yield. In order to achieve the above objectives, the present invention provides the following technical solutions:
A preparation method of 2,4,6-triiodoresorcinol, including the following steps:
(1) Dissolve concentrated sulfuric acid in methanol to obtain methanolic sulfuric acid solution A;
(2) Add resorcinol and potassium iodide to solution A in batches with stirring at a molar ratio of 1:3, then heat to 50°C, add 30% mass fraction of hydrogen peroxide solution dropwise with stirring, After the addition is completed, react at 50-54°C for 1-3 hours;
(3) Cool to room temperature, remove the solution under vacuum under stirring, pour the residual liquid into cold water, and precipitate the crude product;
(4) Recrystallize from tetrachlorethylene to obtain white crystalline 2,4,6-triiodoresorcinol.
Compared with the existing technology, the beneficial effects of the present invention are:
(1) The method for synthesizing iodophenol is the oxidative iodine process. The highly active iodination agent-iodine chloride generated in the process is instantly generated and iodine is consumed immediately. The reaction by-products are water and potassium sulfate; harvest High efficiency, low cost, green response, high efficiency, safe and controllable.
(2) Hydrogen peroxide is a green oxidant, and the only by-product (waste) is water. Hydrogen peroxide concentration of 30% is safe. With the gradual addition of hydrogen peroxide, the reaction proceeds step by step, making the process safe and controllable.
(3) No metal catalyst is used in the oxidation and iodination processes, and the process is green and environmentally friendly.
4. Used in the synthesis of 3-butoxyphenol
Polybenzoxazine resin is a new type of thermosetting resin developed on the basis of traditional phenolic resin. Its monomer benzoxazine is composed of phenols, formaldehyde or paraformaldehyde and primary amines through a condensation reaction. The obtained six-membered heterocyclic compound can be ring-opening polymerized and solidified by heating to form a polybenzoxazine resin with a cross-linked structure similar to phenolic resin. No low-molecular volatile components are released during the curing process. Therefore, it is a new way to improve the performance of phenolic resin. people pay more and more attention to it. 3-Butoxyphenol is an important intermediate in the synthesis of polybenzoxazine resin. CN201711016387 provides a synthesis method of 3-butoxyphenol with mild reaction conditions, low cost, normal pressure operation, little pollution, and high yield. In order to achieve the above object, the technical solution of the present invention is: a synthesis method of 3-butoxyphenol, which is carried out according to the following steps:
a. Add 400 to 450 ml of acetonitrile solvent to a 500 ml three-necked flask equipped with a stirrer, thermometer and reflux condenser, add 30 to 35g of resorcinol and 16 to 18g of potassium carbonate to the three-necked flask, and stir After 1 hour, add 8 to 9 g of n-butane bromide dropwise to the three-necked flask to obtain a mixed solution. Control the dripping to be completed within 50 to 60 minutes. Then place the three-necked flask containing the mixed solution in a constant-temperature magnetic stirrer and stir at 82 Stir the reaction for 18 to 24 hours at a temperature of ~90°C. After the stirring reaction is completed, cool to room temperature. Then pour the mixed solution in the three-necked flask into a rotary evaporator for evaporation. After all the acetonitrile in the mixed solution has evaporated, evaporate the acetonitrile completely. The final reaction solution is taken out and set aside.
b. Add 50 to 100 ml of methylene chloride to the reaction solution obtained in step a, stir evenly and then dropwise add 10% hydrochloric acid solution, adjust the pH value of the reaction solution to 2, and adjust the pH value Pour the subsequent reaction solution into the separatory funnel, then add 100 to 200 ml of methylene chloride into the separatory funnel, cover it tightly, invert the separatory funnel and shake it slightly for 3 times, then stand the separatory funnel upright. Let it stand for 1 hour in the edge of the iron stand, take out the lower solution in the layered solution in the separatory funnel, pour it into a clean separatory funnel, add 100 to 200 ml of 50°C deionized water, and repeat the above extraction operation. 3 times, let it stand for 1 hour, and take out the lower solution in the layered solution in the separatory funnel.
c. Pour the lower solution obtained in step b into a clean separatory funnel, add 100 to 200 ml of diethyl ether and 30 to 50 ml of 10% sodium hydroxide solution in sequence, repeat the extraction operation 3 times, and let stand. After 1 hour, take out the lower layer of the layered solution and place it in a beaker. Then add 10% hydrochloric acid solution dropwise into the beaker until the pH value of the solution reaches 2.
d. Pour the solution with a pH value of 2 obtained in step c into a clean separatory funnel, add 100 to 200 ml of methylene chloride, repeat the extraction operation 3 times, let it stand for 1 hour, and then take out the stratified solution. The lower dark brown solution is poured into a rotary evaporator and evaporated for 2 hours to obtain 3-butoxyphenol.
Due to the adoption of the above technical solution, the synthesis method of 3-butoxyphenol of the present invention has the following advantages: the present invention utilizes the active group hydroxyl (-OH) in resorcinol and the halogen (-OH) of n-bromobutane Br), and use the principle of adjusting pH and compatibility between organic and inorganic to solve the problem of too many by-products in the process of synthesizing 3-butoxyphenol, and synthesize 3-butoxyphenol. . The synthesis method of 3-butoxyphenol involved in the present invention has simple process, short reaction cycle, high product yield, low synthesis cost and low environmental pollution. It is different from the traditional synthesis of 3-butoxyphenol using a series of monoetherified hydroxyl protection methods. Butoxyphenol method. At the same time, the 3-butoxyphenol synthesized by the present invention can not only be used as an intermediate for synthesizing benzoxazine but also become a precursor of more polymers, and has broad application prospects.
Main reference materials
[1] CN201610954300.2 Preparation method of m-methoxyphenol
[2]CN200310109889.9 Chemical synthesis method of 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine
[3]CN201810353401.3 A preparation method of 2,4,6-triiodoresorcinol
[4]CN201711016387.X A synthesis method of 3-butoxyphenol
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