WO2017124675A1

WO2017124675A1 - Method for using menthene diol to synthesise carvacrol

Info

Publication number: WO2017124675A1
Application number: PCT/CN2016/084008
Authority: WO
Inventors: 刘晓涛; 李绍玉; 吴庆典; 万猛; 张建洋; 刘颖; 汤海潮
Original assignee: 淮安万邦香料工业有限公司
Priority date: 2016-01-22
Filing date: 2016-05-31
Publication date: 2017-07-27
Also published as: CN105693474A; CN105693474B

Abstract

Disclosed is a method for using a menthene diol to synthesise carvacrol, said method comprising the following steps: step 1, dissolving a menthene diol and a catalyst A in a solvent, heating so that the menthene diol undergoes a dehydration and open ring rearrangement reaction to produce an isodihydrocarvone, and after the reaction is over, using an alkali solution to neutralise the pH to 7-8, standing and layering, and performing organic phase reduced pressure distillation to obtain an isodihydrocarvone end product; step 2, dissolving the isodihydrocarvone produced in step 1 and a catalyst B in a solvent, heating for an oxidative dehydrogenation reaction to produce carvacrol, filtering and separating the catalyst B, and performing reduced pressure distillation on the filtrate to obtain a carvacrol end product. The raw materials are easy to source and cheap, the synthesis process is green and environmentally friendly, post-treatment and purification is only distillation, the process is simple, the catalysts may be recycled, and the method is suitable for industrial production.

Description

Instruction manual

Method for synthesizing carvacrol from captendiol

Technical field

The invention belongs to the technical field of chemical industry, and relates to a chemical synthesis method, in particular to a method for synthesizing carvacrol by using capricene glycol.

technical background

Carvacrol is a colorless to pale yellow thick oily liquid with thymol odor. It is a commonly used food additive and fragrance. It has low toxicity and natural characteristics and is approved for safety in the US and Europe. Food additive. Natural carvacrol is mainly found in a variety of Labiatae, such as thyme, oregano. Carvacrol has a wide range of functions and applications. It has good growth inhibition effect on bacteria, yeasts, fungi, insects and mites by destroying and changing the cell membrane structure of the pathogenic bacteria, or the structure of the mycelium, or effectively inhibiting the activity of the conidia. Good antibacterial and insecticidal effects. It is an active component of thyme and blood sputum, and achieves platelet activation by mediating the signal transduction pathway of anti-thrombotic protein via the G13 protein-linked R hoA/ R ho-kinase. These effects make it widely used as a natural antibacterial preservative in food, pharmaceuticals, cosmetics and other products.

At present, there are two main methods for the synthesis of carvacrol: one is to use a carotenoid as a raw material to aromatize and synthesize carvacrol under the action of a strong acid or a metal catalyst. Such as

CN101475448A reports the use of organic or inorganic acid as a main catalyst, PEG-400 or PEG-600 as a cocatalyst to promote the intramolecular rearrangement of carvone to form carvacrol; in addition, Linstead, RP reported that metal palladium catalyzed parsley The reaction of ketone dehydroisomerization to synthesize carvacrol (JoL ma/ o/ fhe O7em/'ca/ 5odefy, 1940, 1139-1147). Excellent method of this type The point is that the reaction selectivity is good and the yield is high, but the raw material carvone itself is a kind of perfume product, and the price is high, which makes the cost advantage of the process greatly discounted. Second, it is synthesized from o-methylphenol as a raw material by a Friedel-Craft reaction with isopropanol or 2-halopropene. For example, a method for synthesizing carvacrol by reacting o-methylphenol with 2-chloropropanone with aluminum trichloride or ferric chloride is reported in the special 1JCN 1488615, but the method has a large amount of aluminum salt and iron salt solid. Waste generation, causing environmental pollution, limits its further application in production.

Summary of the invention

In view of the deficiencies of the prior art, the present invention provides a method for synthesizing carvacrol with caprolene glycol, which is effective for the use of caprolactone glycol, and provides a novel method for synthesizing carvacrol while turning waste into treasure.

The invention is achieved by the following technical solutions:

A method for synthesizing carvacrol with captenol comprises the following steps:

In the first step, the caprolactam and the catalyst A are dissolved in a solvent, and the dehydration and ring-opening rearrangement reaction of the active constituent diol of the caprolactone is heated to form iso-dihydrocarvone, and the reaction is monitored by gas chromatography. The raw material disappears and the reaction ends. After the reaction is completed, the pH is adjusted to 7 to 8 with a 5 to 10 wt% NaHCO ₃ aqueous solution, and the mixture is allowed to stand for stratification, and the organic phase is subjected to vacuum distillation to obtain a product of iso-dihydrocarvone;

In the second step, the iso-dihydrocarvone and the catalyst B prepared in the first step are dissolved in a solvent, and dehydrogenation reaction is generated by heating to form carvacrol, which is monitored by gas chromatography during the reaction, when iso-dihydrocarton When the ketone content is 30% to 40%, the reaction is terminated, the catalyst B is separated by filtration, the filtrate is subjected to vacuum distillation, the unreacted iso-dihydrocarvone and the solvent are recovered, and the rectification is carried out to obtain a finished carvacrol. The chemical reaction equation is as follows:

twenty three

The advancement of the present invention is:

In the first step, the solvent is an inert substance capable of azeotroping with water, including toluene, fluorobenzene, anisole, xylene, and the catalyst is an organic or inorganic strong acid, including trifluoroacetic acid, sulfonate.

30; The reaction temperature is 110 to 160 ° C, and the reaction time is 3 to 7 h;

In the second step, the solvent is an inert substance capable of azeotroping with water, and includes toluene, fluorobenzene, anisole, and xylene, and the amount thereof is adjusted according to the temperature required for the reaction. Catalyst B is a Cu-C composite catalyst; the mass ratio of iso-dihydrocarvone to catalyst B is 500: 100 to 500; the reaction temperature is 190 to 230 ° C, and the time is 4 to: LOh; It is recycled at least once and the catalytic activity is not diminished.

A further development of the invention is:

In the second step, the dehydrogenation reaction slows down and the by-products increase, so the selectivity is best when the remaining raw materials are close to 30~40%, and the reaction can be stopped at this time; the pump is continuously used to react to the reaction liquid during the reaction. The lower drum air continuously distills off the water produced by the dehydrogenation to promote the conversion of the reaction, and the air or oxygen atmosphere is more favorable for the reaction.

The beneficial effects of the invention are:

The raw material of the invention is convenient, cheap and easy to obtain; the synthesis process is green and environmentally friendly; the post-treatment purification is only through rectification, and the process is simple; the catalyst can be recycled, suitable for industrial production, detailed description

Embodiment 1:

Step 1 In a 1000 mL reactor, 600 g of 3⁄4; hexanediol, 300 g of toluene and 18 g of p-toluenesulfonic acid were added, and then reacted at 120 to 150 ° C for about 3 to 4 hours. After GC showed that the reaction was completed, the temperature of the kettle was lowered. After 40 ° C or less, 300 g of a 5 wt% aqueous solution of NaHCO _{3 was} added to wash to pH = 7 to 8, and the organic phase obtained by liquid separation was subjected to vacuum distillation to obtain 510 g of iso-dihydrocarvone at a content of more than 90%, and the yield was 85%.

In the second step, 510 g of iso-dihydrocarvone and 40 g of xylene obtained above were put into a 1000 mL three-necked flask, and then 400 g of catalyst B was added, and the reaction was carried out under reflux at 190 to 220 ° C, and the pump was continuously used during the reaction. The reaction liquid was blown into the air for about 4 to 5 hours. The GC showed the remaining 30% of iso-dihydrocarvone. The reaction was stopped, the catalyst was removed by filtration, and the filtrate was subjected to vacuum distillation. 37 g of the solvent and 151 g of unreacted raw materials were recovered. A rectification product obtained 254 g of a carvacrol finished product having a content of more than 98%, and an effective yield of 71%. The catalyst B obtained by filtration can be reused.

Note: The "effective yield" in the second step is calculated based on the amount of iso-dihydrocarvone involved in the reaction (excluding recovery).

Embodiment 2:

Step 1 In a 1000 mL reactor, 600 g of 3⁄4; hexanediol, 300 g of toluene and 15 g of p-toluenesulfonic acid were added, and then reacted at 120 to 150 ° C for about 4 to 5 hours. After GC showed that the reaction was completed, the temperature of the kettle was lowered. Below 40 ° C, 250 g of a 5 wt% aqueous solution of NaHCO _{3 was} added to wash to pH = 7 to 8, and the organic phase obtained by liquid separation was subjected to vacuum distillation to obtain 504 g of iso-dihydrocarvone at a content of more than 90%, and the yield was 84%. In the second step, 504 g of iso-dihydrocarvone and 35 g of xylene obtained above were put into a 1000 mL three-necked flask, and then 300 g of catalyst B was added, and the reaction was carried out under reflux at 190 to 220 ° C, and the pump was continuously used during the reaction. The reaction liquid was blown into the air for about 5 to 6 hours. The GC showed the remaining 38% of iso-dihydrocarvone. The reaction was stopped, the catalyst was removed by filtration, and the filtrate was subjected to vacuum distillation. 30 g of the solvent and 190 g of unreacted raw materials were recovered. A rectification product obtained 234 g of a carvacrol finished product having a content of more than 98%, and an effective yield of 74.5%.

Embodiment 3:

Step 1 In a 1000 mL reactor, 600 g of 3⁄4: hexanediol, 300 g of toluene and 7 g of p-toluenesulfonic acid were added, and then reacted at 120 to 150 ° C for 6 to 7 hours. After GC showed that the reaction was completed, the temperature of the kettle was lowered to 40. Below °C, 200 g of a 5 wt% aqueous solution of NaHCO _{3 was} added to wash to pH = 7 to 8, and the organic phase obtained by liquid separation was subjected to vacuum distillation to obtain 486 g of iso-dihydrocarvone at a content of more than 90%, and the yield was 81%.

In the second step, 486g of iso-dihydrocarvone and 30g of xylene obtained above were put into a 1000 mL three-necked flask, and then 150 g of catalyst B was added, and the reaction was carried out under reflux at 190 to 220 ° C, and the pump was continuously used during the reaction. The reaction liquid was blown into the air for about 9 to 10 hours. The GC showed the remaining 34% of iso-dihydrocarvone. The reaction was stopped, the catalyst was removed by filtration, and the filtrate was subjected to vacuum distillation. The solvent was recovered in 28 g and the unreacted raw material was 164 g. A rectification product obtained 251 g of a carvacrol finished product having a content of more than 98%, and an effective yield of 78%.

Embodiment 4:

Step 1 In a 1000 mL reactor, 600 g of 3⁄4; hexanediol, 300 g of toluene and 10 g of sulfuric acid (60 wt%) were added, and then reacted at 120 to 150 ° C for about 4 to 5 hours. After GC showed that the reaction was over, the temperature of the kettle was lowered. Up to 40 ° C, add 380g of 10wt% NaHC0 ₃ aqueous solution to wash PH=7~8, the organic phase obtained by liquid separation was subjected to vacuum distillation to obtain 472 g of iso-dihydrocarvone at a content of more than 90%, and the yield was 78.8%.

In the second step, 472g of iso-dihydrocarvone and 36g of chlorobenzene obtained above were put into a 100 mL three-necked flask, and then 200 g of catalyst B was added, and the reaction was carried out under reflux at 190 to 220 ° C, and the pump was continuously used during the reaction. The reaction liquid was blown into the air for about 7 to 8 hours. The GC showed the remaining 35% of iso-dihydrocarvone. The reaction was stopped, the catalyst was removed by filtration, and the filtrate was subjected to vacuum distillation. The solvent was recovered in 35 g and the unreacted raw material was 165 g. A rectified distillation yielded 232 g of carvacrol finished product with a content of more than 98%, and the effective yield was 75.7%.

Embodiment 5:

Step 1 In a 1000 mL reactor, 600 g of 3⁄4; hexanediol, 300 g of toluene and 16 g of sulfuric acid (60 wt%) were added, and then reacted at 120 to 150 ° C for about 3 to 4 hours. After GC showed that the reaction was over, the temperature of the kettle was lowered. To 40 ° C or less, 600 g of a 10 wt% aqueous solution of NaHCO _{3 was} added to wash to pH = 7 to 8, and the organic phase obtained by liquid separation was subjected to vacuum distillation to obtain 477 g of iso-dihydrocarvone at a content of more than 90%, and the yield was 79.5%. .

In the second step, 477 g of iso-dihydrocarvone and 39 g of chlorobenzene obtained above were put into a 1000 mL three-necked flask, and then 160 g of catalyst B was added, and the reaction was carried out under reflux at 190 to 220 ° C, and the pump was continuously used during the reaction. The reaction liquid was blown under the surface for about 7 to 8 hours. The GC showed the remaining 30% of iso-dihydrocarvone. The reaction was stopped, the catalyst was removed by filtration, and the filtrate was subjected to vacuum distillation. The solvent was recovered in 35 g and the unreacted raw material was 143 g. A rectification yielded 240 g of carvacrol finished product with a content of more than 98%, and the effective yield was 72%.

Claims

Claim

A method for synthesizing carvacrol with captenol, characterized in that it comprises the following steps: In the first step, capping diol and catalyst A are dissolved in a solvent, and heating causes dehydration and ring-opening rearrangement of the caprolactam Reaction, the formation of iso-dihydrocarvone, after the reaction is completed, neutralize the pH to 7~8 with an alkali solution, leave the layer to stand, and distill the organic phase to obtain the finished product of iso-dihydrocarvone; The iso-dihydrocarvone and the catalyst B prepared in the first step are dissolved in a solvent, and dehydrogenation reaction is generated by heating to form carvacrol, and the catalyst B is separated by filtration, and the filtrate is subjected to vacuum distillation to obtain a finished carvacrol;

The catalyst A is an organic or inorganic acid, and the catalyst B is a carbon-based composite catalyst.

The method for synthesizing carvacrol with capping diol according to claim 1, wherein the chemical reaction equation is as follows: /:, H

J

The method for synthesizing carvacrol with capping diol according to claim 1, which is characterized in that:

In the first step, the catalyst A is trifluoroacetic acid, sulfonic acid, sulfuric acid or hydrochloric acid.

The method for synthesizing carvacrol with capping diol according to claim 1, wherein in the second step, the carbon-based composite catalyst B is a catalyst in which copper is supported on a carbon medium material, wherein copper The content is 3 wt%.

The method for synthesizing carvacrol with capping diol according to claim 1, wherein in the first step and the second step, the solvent is toluene, fluorobenzene, anisole or xylene. One or two of the mix.

The method for synthesizing carvacrol with capping diol according to claim 1, wherein:

In the first step, the reaction temperature is 110~160 ° C;

In the second step, the reaction temperature is 190 to 230 °C.

The method for synthesizing carvacrol with capping diol according to claim 1 or 6, wherein: the step 1 shows the end of the reaction by GC; and the gas is detected by gas chromatography during the second step of the reaction. When the iso-dihydrocarvone content is 30%-40%, the reaction is terminated, and the reaction continues to cause a significant decrease in selectivity.

In the first step, the mass ratio of the 3⁄4 diol and the catalyst A in the capene diol is 1000: 5~30; in the second step, the mass ratio of the iso-dihydrocarvone to the catalyst B is 500. : 100~500.

The method for synthesizing carvacrol with capping diol according to claim 1, wherein in the second step, the catalyst B obtained by filtration is recycled at least once.

The method for synthesizing carvacrol with capping diol according to claim 1, which is characterized in that one of the alkali solutions is a 5 to 10 wt% NaHCO^ solution.