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Method for directly producing o-ethoxyphenol from ethylene

A technology of o-ethoxyphenol and catechol, which is applied in the field of synthesis of fine chemicals, can solve the problems of cumbersome reaction steps, high equipment requirements, and large environmental pollution, and achieve high selectivity, short reaction routes, and low The effect of production costs

Active Publication Date: 2018-12-21
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, the o-nitrophenol method uses o-nitrophenol and bromoethane as raw materials, benzyltriethylammonium bromide as a phase transfer catalyst, first synthesizes o-nitrophenethyl ether, and then generates o-nitrophenol through sodium sulfide reduction or hydrogenation reduction. Aminophenetole, sodium nitrite-hydrochloric acid diazotization, acidic hydrolysis to obtain o-hydroxyphenethyl ether, the reaction steps are loaded down with trivial details, the process is complex, the yield is low, and the three wastes are many; and when using diethyl sulfate method to synthesize, diethyl sulfate It is a highly toxic drug, and it needs to be strictly monitored during the whole process of use to avoid poisoning accidents. In addition, only one ethyl group in diethyl sulfate can be used during the reaction process. After the reaction, the by-product of monoethyl sulfate needs to be passed through high temperature. Decomposition treatment; although diethyl carbonate is safer and more environmentally friendly than diethyl sulfate, its price is significantly higher than that of diethyl sulfate, which makes the diethyl carbonate method economically unfeasible; It is prepared by reacting diphenol with ethyl chloride or ethyl bromide, but this method will produce a large amount of acidic hydrogen halide gas, which requires an equivalent amount of lye to neutralize, and chlorine or bromide ions are highly corrosive and require high equipment. The environmental pollution is large, and the reaction is easy to generate double-etherification by-products, which need to be reacted in a water-organic solvent heterogeneous system with the help of a phase transfer catalyst, and the process is complicated

Method used

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  • Method for directly producing o-ethoxyphenol from ethylene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] In a 100mL autoclave, add 11.0g (0.1mol) catechol, 43.5g (50mL) xylene, 0.5g phosphomolybdic acid and 0.1g potassium iodide, cover the autoclave, and pump out most of the Air, start heating and start stirring, when the heating temperature rises to 180°C, feed ethylene gas to make the pressure in the kettle reach 1.60MPa, and maintain the reaction at this pressure for 8 hours; release the ethylene gas that has not participated in the reaction through the pressure reducing valve; then After cooling down, the catalyst was recovered by filtration, and most of the solvent xylene was removed by distillation of the filtrate under reduced pressure, and the residue was separated and reclaimed catechol (7.3g, raw material conversion rate 33.7%) through column chromatography, by-product o-ethoxyphenetole (0.39 g) Collect 3.81 g of o-ethoxyphenol finished product (purity 99.2%, selectivity 90.7%).

Embodiment 2

[0026]In a 100mL autoclave, add 22.0g (0.2mol) of catechol, 49g (50mL) of tetrahydronaphthalene, 1.0g of ruthenium dioxide and 0.1g of zinc bromide, cover the autoclave, and pump out the large Part of the air, start heating and start stirring, when the temperature rises to 240°C, feed ethylene gas to make the pressure in the kettle reach 1.0MPa, and maintain the reaction at this pressure for 8 hours; after the reaction is completed and cooled to room temperature, pass through the pressure reducing valve Emit the ethylene gas that does not participate in the reaction, and reclaim the catalyzer by filtration under reduced pressure; Then remove most of the solvent tetrahydronaphthalene by distillation under reduced pressure, and the residue reclaims catechol (12.05g, raw material conversion rate 45.2%) through column chromatography separation, by The product was o-ethoxyphenetole (0.26g), and 11.2g of finished product o-ethoxyphenol was collected (purity 99.1%, selectivity 97.7%)....

Embodiment 3

[0028] In a 100mL autoclave, add 66.0g (0.6mol) catechol, 37.8g (40mL) diphenyl ether, 2.0g20% phosphotungstic acid / TiO 2 and 1.0g sodium bromide, cover the autoclave, pump out most of the air in the autoclave, start heating and start stirring, when the heating temperature rises to 260°C, feed ethylene gas to make the pressure in the autoclave reach 0.6MPa, and maintain the pressure Insulation reaction for 6 hours; after the reaction, the ethylene gas that did not participate in the reaction was released through the pressure reducing valve, and after cooling, the catalyst was recovered by filtration under reduced pressure, and the gas chromatography area normalization method was used for analysis. The raw material catechol (38.74g, conversion rate 41.3%) , the by-product o-ethoxyphenetole (0.99g), the target compound o-ethoxyphenol (33.5g, selectivity 97.1%).

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Abstract

The invention relates to a method for directly producing o-ethoxyphenol from ethylene. The method comprises the following steps: putting catechol, a solvent, a main catalyst and an auxiliary catalystinto a high-pressure kettle, sealing the high-pressure kettle, pumping out most air in the kettle by using a pump, starting stirring, and heating to 180-260 DEG C; introducing an ethylene gas till thepressure intensity in the kettle is up to 0.6-1.6MPa, carrying out a reaction for 4-8 hours while the pressure intensity is maintained, discharging the unreacted ethylene gas through a depressurization valve after the reaction is completed, cooling to 100 DEG C or less, and carrying out vacuum suction filtration so as to recycle the catalyst; recycling the catechol from a reaction liquid throughcolumn chromatography so as to obtain a product, or carrying out vacuum distillation to remove most solvent and obtain a crude product with the catechol and the product as main components, and distilling the crude product, thereby obtaining a pure product of o-ethoxyphenol. The method is simple in process, short in reaction route, high in production efficiency and very environmentally friendly, the production cost can be reduced, in addition, waste generation can be reduced, and the waste treatment cost can be reduced.

Description

[technical field] [0001] The invention relates to the technical field of synthesis of fine chemicals, in particular to a method for directly producing o-ethoxyphenol by utilizing ethylene. [Background technique] [0002] Ethyl vanillin has a strong vanilla bean aroma with a long-lasting aroma, which is 3-4 times that of vanillin. It is an indispensable and important raw material in today's food additive industry. At the same time, it is a free radical scavenger in medicine, has a good function of eliminating active oxygen, can resist oxidation and prevent the occurrence of cardiovascular and other diseases, and has the functions of preventing diseases, anti-aging, and promoting human health. In addition, ethyl vanillin can also be used as a feed additive, a brightener in the electroplating industry, etc. Therefore, ethyl vanillin has very considerable market application value. O-ethoxyphenol is an important raw material in the production process of ethyl vanillin, and it i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C43/23C07C41/06C07C41/36
CPCC07C41/06C07C41/36C07C43/23Y02P20/584
Inventor 毛海舫王洪朝张文祥刘吉波胡晓钧张驰原
Owner SHANGHAI INST OF TECH