A process for the co-production of xanthene and ethylphenol

Abstract

The application provides a method for co-production of xanthene and ethyl phenol, and belongs to the technical field of organic chemical industry. The method is to use phenol and calcium carbide as raw materials, and to use calcium phenate as a catalyst to synthesize xanthene and ethyl phenol by heating reaction in an inert atmosphere and a closed reactor. The calcium carbide used in the method is widely available and low in price, and the method has the advantages of no need of additional catalyst and solvent, short route, high product yield and the like, and overcomes the problems in the prior art. In addition, the method co-produces xanthene and ethyl phenol, and significantly improves the economy of the traditional phenol alkylation process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic chemical industry, and in particular to a method for co-production of xanthene and ethyl phenol. BACKGROUND

[0002] Ethyl phenol, as a kind of short-chain alkyl phenol, can be used to produce phenolic resin, rubber antioxidant, surfactant, low-residue pesticide and other important chemicals. At present, the methods for producing ethyl phenol include crude oil separation method, ethylbenzene hydrolysis method and phenol alkylation method. Among them, the phenol alkylation method is the most common method, which generates products by alkylation reaction of phenol and olefin / alcohol under the action of acidic catalyst. However, on the acidic catalyst, the olefin is prone to oligomerization, and the alcohol is prone to dehydration reaction, resulting in low selectivity of products. Chinese patent (CN201010123979.3) reports a method for synthesizing 4-ethyl phenol by using diethyl carbonate and phenol as raw materials, and modified microporous molecular sieve as catalyst in a mixed solution of ethanol and water. The selectivity of the product is improved, but the reaction system is complex, and the source of diethyl carbonate is not extensive. Chinese patents (CN201410558325.1) and (CN202010199444.8) respectively report methods for preparing 4-ethyl phenol by biomass catalytic pyrolysis and microbial fermentation, with a low product yield of about 10%.

[0003] Xanthene compounds mainly exist in herbs, fungi and microorganisms. Different substituents on the benzene ring endow them with different chemical and biological properties, and they have important applications in the fields of medicine, fluorescent materials and dyes. Except for a few that can be extracted and separated from natural plants such as mangosteen and mangosteen peel, xanthene compounds are mostly synthesized by condensation of 2-naphthol with aldehyde using protonic acid or Lewis acid catalyst. Chinese patents (CN201310103521.5) and (CN201410351149.4) respectively disclose methods for synthesizing xanthene compounds by condensation of aromatic aldehyde with 2-naphthol using strong acid ion exchange resin and Bronsted acidic ionic liquid catalyst. This method faces a series of production and environmental problems such as catalyst preparation and recovery, generation of large amount of wastewater and equipment corrosion.

[0004] In summary, ethyl phenol and xanthene are synthesized by different methods respectively, both of which need strong acidic catalyst. Some of the processes have complex reaction systems, non-extensive raw material sources, and some of the processes have problems of wastewater and equipment corrosion. SUMMARY

[0005] The present application provides a method for co-production of xanthene and ethyl phenol by one-pot reaction of phenol and calcium carbide. The method uses calcium carbide as raw material, which is widely available and low in price. The method has the advantages of no need of external catalyst and solvent, short route, high yield of products, etc. and overcomes the problems in the prior art. In addition, the method co-produces xanthene and ethyl phenol, which significantly improves the economy of the traditional phenol alkylation process.

[0006] The technical scheme of the present application is as follows:

[0007] A method for co-production of xanthene and ethyl phenol, which uses phenol and calcium carbide as raw materials, and calcium phenate as catalyst to synthesize xanthene and ethyl phenol by heating reaction in an inert atmosphere and a closed reactor.

[0008] Further, the calcium phenate, i.e. the catalyst required for the alkylation reaction, is generated in the reaction process of phenol and calcium carbide.

[0009] Preferably, the inert atmosphere can be nitrogen or argon atmosphere, etc. Preferably, the phenol is anhydrous phenol.

[0010] Further, the heating reaction temperature is 250-400℃; preferably, the heating reaction temperature is 325-375℃.

[0011] Further, the heating reaction time is 0.5-6h. The reaction time is related to the reaction temperature. Below 350℃, the longer the reaction time, the higher the yield of xanthene and ethyl phenol, but the optimal reaction time should be determined by considering the production efficiency (yield per unit time) and total yield. Above 350℃, the yield of xanthene and ethyl phenol decreases with the increase of reaction time.

[0012] Further, the molar ratio of calcium carbide to phenol is 1:(1-16); preferably, the molar ratio of calcium carbide to phenol is 1:(8-16). Generally, the more the amount of phenol added, the more conducive to the alkylation reaction and hydrogenation reaction, and the higher the total yield of xanthene and ethyl phenol.

[0013] Further, the pressure of the heating reaction comes from the pressure generated by the heating of the raw materials, without the need for additional pressurization.

[0014] Further, the calcium carbide is ground to 50-120 mesh before being added to the closed reactor. Generally, the larger the mesh size of the ground calcium carbide (i.e. the finer the calcium carbide), the higher the total yield of xanthene and ethyl phenol. Preferably, the mesh size of the ground calcium carbide is 80-100 mesh.

[0015] Further, the products of the heating reaction include xanthene, 2-ethyl phenol and 4-ethyl phenol, etc.

[0016] Further, the product of the heating reaction is cooled, and then separated into gas, solid and liquid phases, and the product xanthene and ethyl phenol are obtained from the liquid phase.

[0017] The reaction mechanism of the calcium carbide and phenol is shown as follows:

[0018]

[0019] During the reaction, the calcium carbide is mainly used for the alkylation of phenol and the dehydration product of phenol. First, the phenol is alkylated with acetylene derived from the calcium carbide to form vinyl phenol or intermolecular dehydration to form diphenyl ether. Then, the vinyl phenol is dehydrated and cyclized with phenol to form xanthene, or the diphenyl ether is alkylated with acetylene derived from the calcium carbide, and then cyclized to form xanthene. The ethyl phenol is formed by hydrogenation of the vinyl phenol with phenol. The calcium phenoxide derived from the calcium carbide has a catalytic effect on the reaction process.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] (1) The calcium carbide raw material is a bulk platform compound, which is widely available and low in price;

[0022] (2) The present application uses the reaction product calcium phenoxide as a catalyst, and does not need to add a catalyst and a solvent, so that the reaction system is simple and the reaction conditions are relatively mild;

[0023] (3) The present application produces xanthene and ethyl phenol in one pot, so that the process flow is short and the economic efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation to the scope of the present application.

[0025] Figure 1 It is a total ion chromatogram of the liquid product in Example 1;

[0026] Figure 2 It is a mass spectrum of the product 2-ethyl phenol in Example 1;

[0027] Figure 3 It is a mass spectrum of the product 4-ethyl phenol in Example 1;

[0028] Figure 4 It is a mass spectrum of the product xanthene in Example 1. DETAILED DESCRIPTION

[0029] As used herein:

[0030] "comprising," "having," "including," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises, has, includes, or contains one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements.

[0031] When equivalent, concentration, or other value or parameter is expressed in a range, a preferred range, or a range of upper and lower preferred values, it is understood that any and all subranges that fall within the range are specifically and explicitly disclosed. For example, where a range of "1 to 5" is disclosed, it is understood that the range of "1 to 4," "1 to 3," "1 to 2," "1 to 2 and 4 to 5," "1 to 3 and 5," etc., are specifically and explicitly disclosed. Where a range of values is disclosed, it is understood that the range includes all values within the range and all integers and fractions within the range.

[0032] "and / or" is used to indicate one or both stated cases can occur, for example, A and / or B includes (A and B) and (A or B).

[0033] The technical solutions of the present application will be described in detail below in combination with specific examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. The specific conditions are not specified in the examples, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not specified by the manufacturer, and are conventional products that can be purchased on the market.

[0034] In the present application, there is no special limitation on the form of the reactor, and a closed reactor well known to those skilled in the art can be used. In the following examples, the reactor is cooled with an ice water bath, but the cooling method is not limited to the ice water bath, and any cooling medium and equipment can be used.

[0035] In the following examples, the solid-liquid mixed product is soaked in tetrahydrofuran (THF), and then the liquid product is separated by filtration. The separation of the solid-liquid product is not limited to the method described, and any solid-liquid separation method well known to those skilled in the art can be used.

[0036] In the present application, the qualitative analysis of the liquid product is performed by GC-MS analysis; the quantitative analysis of 2-ethylphenol, 4-ethylphenol, and xanthene is performed by GC analysis, and the yield of each product is the percentage of the molar mass of each product to the molar mass of the calcium carbide added.

[0037] Example 1

[0038] A method for co-production of xanthene and ethyl phenol: calcium carbide was ground to 80-100 mesh, calcium carbide and anhydrous phenol were added into a sealed reactor in a molar ratio of 1:8, the reactor was sealed after purging the air in the reactor with nitrogen, and then heated to 350°C, and reacted for 6h. After the reaction was completed, the reactor was cooled to room temperature using an ice water bath, the gaseous product was collected, and then the solid-liquid mixed product was soaked in tetrahydrofuran (THF) for 12h, and the liquid product was obtained by filtration.

[0039] The GC results in GC-MS are shown in Figure 1 .The MS results of the peak at a retention time of 27.8min are shown in Figure 1 , which is consistent with the mass spectrum of 2-ethyl phenol in the NIST library; the MS results of the peak at a retention time of 29.3min are shown in Figure 2 , which is consistent with the mass spectrum of 4-ethyl phenol in the NIST library; and the MS results of the peak at a retention time of 51.7min are shown in Figure 3 , which is consistent with the mass spectrum of xanthene in the NIST library. Figure 4

[0040] The GC quantitative analysis showed that the yields of 2-ethyl phenol, 4-ethyl phenol, and xanthene were 12.4%, 7.3%, and 24.2%, respectively, and the total yield of the products was 43.9%.

[0041] Example 2

[0042] The difference from Example 1 is that the reaction time is 0.5h. The GC showed that the yields of 2-ethyl phenol, 4-ethyl phenol, and xanthene were 6.5%, 12.6%, and 7.1%, respectively. The total yield of the products was 26.2%.

[0043] Example 3

[0044] The difference from Example 1 is that the reaction time is 2h. The GC showed that the yields of 2-ethyl phenol, 4-ethyl phenol, and xanthene were 14.5%, 11.7%, and 17.6%, respectively. The total yield of the products was 43.8%.

[0045] Example 4

[0046] The difference from Example 1 is that the reaction temperature is 250°C, and the reaction time is 2h. The GC showed that the yields of 2-ethyl phenol, 4-ethyl phenol, and xanthene were 1.5%, 4.2%, and 0.8%, respectively. The total yield of the products was 6.5%.

[0047] Example 5

[0048] The difference from Example 4 is that the reaction temperature is 275°C. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 4.8%, 9.7%, 2.1% respectively by GC. The total yield of products is 16.6%.

[0049] Example 6

[0050] The difference from Example 4 is that the reaction temperature is 300°C. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 6.5%, 12.5%, 6.4% respectively by GC. The total yield of products is 25.4%.

[0051] Example 7

[0052] The difference from Example 6 is that the reaction time is 6h. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 13.1%, 13.9%, 15.1% respectively by GC. The total yield of products is 42.1%.

[0053] Example 8

[0054] The difference from Example 4 is that the reaction temperature is 325°C. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 13.2%, 13.6%, 15.9% respectively by GC. The total yield of products is 42.7%.

[0055] Example 9

[0056] The difference from Example 4 is that the reaction temperature is 375°C. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 14.2%, 9.2%, 17.1% respectively by GC. The total yield of products is 40.5%.

[0057] Example 10

[0058] The difference from Example 4 is that the reaction temperature is 400°C. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 12.7%, 7.4%, 16.6% respectively by GC. The total yield of products is 36.7%.

[0059] Example 11

[0060] The difference from Example 10 is that the reaction time is 6h. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 10.5%, 5.5%, 14.8% respectively by GC. The total yield of products is 30.8%.

[0061] Example 12

[0062] The difference from Example 3 is that the molar ratio of calcium carbide to phenol is 1:1. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 0.7%, 1.1%, 0.1% respectively as measured by GC. The total yield of products is 1.9%.

[0063] Example 13

[0064] The difference from Example 3 is that the molar ratio of calcium carbide to phenol is 1:4. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 5.6%, 9.2%, 8.3% respectively as measured by GC. The total yield of products is 23.1%.

[0065] Example 14

[0066] The difference from Example 3 is that the molar ratio of calcium carbide to phenol is 1:16. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 17.6%, 16.7%, 21.2% respectively as measured by GC. The total yield of products is 55.5%.

[0067] Example 15

[0068] The difference from Example 14 is that the reaction time is 6h. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 21.2%, 17.1%, 26.0% respectively as measured by GC. The total yield of products is 64.3%.

[0069] Example 16

[0070] The difference from Example 3 is that the calcium carbide is ground to 20-40 mesh. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 8.9%, 7.3%, 10.4% respectively as measured by GC. The total yield of products is 26.6%.

[0071] Example 17

[0072] The difference from Example 3 is that the calcium carbide is ground to 40-60 mesh. The yields of 2-ethylphenol, 4-ethylphenol, xanthene are 10.6%, 9.7%, 14.2% respectively as measured by GC. The total yield of products is 34.5%.

[0073] The reaction raw materials, conditions and results of Examples 1-17 are shown in Table 1.

[0074] Table 1 Reaction raw materials, conditions and results of Examples 1-17 of the present application

[0075]

[0076] As shown in Table 1, the more phenol and the larger the grinding mesh of calcium carbide, the higher the yield of xanthene and 2- / 4-ethylphenol; the reaction temperature and time have different effects on the yield of single product, the yield of xanthene increases first and then decreases with the increase of reaction temperature, and reaches the maximum at 350℃, and gradually increases with the increase of reaction time. Because high temperature can lead to the side chain rupture of 2- / 4-ethylphenol, lower temperature and longer time (300℃, 6h) are the most favorable for the generation of ethylphenol.

[0077] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not limited to them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

[0078] In addition, those skilled in the art can understand that although some embodiments herein include certain features rather than others included in other embodiments, the combination of features of different embodiments means to be within the scope of the present application and forms different embodiments. For example, in the above claims, any one of the claimed embodiments can be used in any combination. The information disclosed in the background section is only intended to deepen the understanding of the overall background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A process for the co-production of xanthene and ethylphenol, characterized in that, The xanthene and ethylphenol are synthesized by heating phenol and calcium carbide in an inert atmosphere and a closed reactor, with calcium phenate as catalyst; The heating reaction is carried out at a temperature of 250-400 ℃; The molar ratio of calcium carbide to phenol is 1:(1-16); The calcium carbide is ground to 50-120 mesh before being added to the closed reactor; The ethylphenol includes 2-ethylphenol and 4-ethylphenol; The calcium phenate is generated during the reaction of phenol and calcium carbide; The heating reaction is carried out at a pressure generated by the heating of the raw materials, without additional pressurization; The phenol is anhydrous phenol.

2. The process for the co-production of xanthene and ethylphenol according to claim 1, characterized in that, The heating reaction is carried out at a temperature of 325-375 ℃.

3. The process for the co-production of xanthene and ethylphenol according to claim 1, characterized in that, The heating reaction is carried out for 0.5-6 h.

4. The process for the co-production of xanthene and ethylphenol according to claim 1, characterized in that, The molar ratio of calcium carbide to phenol is 1:(8-16).

5. The process for the co-production of xanthene and ethylphenol according to claim 1, characterized in that, The calcium carbide is ground to 80-100 mesh.

6. The process for the co-production of xanthene and ethylphenol according to claim 1, characterized in that, The inert atmosphere is selected from nitrogen or argon.

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