Decoloration method of 2-methyl-1-(9.9-dibutyl fluorenyl)-2-morpholinyl-1-acetone crude product

Abstract

The invention belongs to the technical field of organic matter decoloration, and particularly relates to a decoloration method of a 2-methyl-1-(9.9-dibutyl fluorenyl)-2-morpholinyl-1-acetone crude product. According to the method, a proper reductive decolorizing agent is added into a reaction crude product solution, colored substances generated by oxidation in a 2-methyl-1-(9.9-dibutyl fluorenyl)-2-morpholinyl-1-acetone crude product are selectively reduced, and colored impurities can be remarkably destroyed by the treatment, so that the chroma of a final product is greatly improved, and the method is suitable for industrial production. The chromaticity standard required by high-purity chemicals is achieved, and the product quality is improved. Moreover, compared with activated carbon decolorization, the method provided by the invention has the advantages that active ingredients of the product cannot be adsorbed by activated carbon, and the product yield is high; meanwhile, activated carbon is not used, so that the risk of generating solid waste and carbon powder residue is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic decolorization, and particularly relates to a decolorization method of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product. BACKGROUND

[0002] In the synthesis process of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone, the key step of alkylation needs to be carried out at a high temperature, and there is usually a basic substance in the reaction system. The active site in the molecular structure of the intermediate or product is extremely unstable in a hot and basic environment, and is prone to oxidative side reactions. These oxidation processes generate colored impurities with conjugated structures, resulting in an undesirable yellow, brown or even darker color of the final product, which seriously affects the appearance quality and purity of the product.

[0003] 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone is used as a photoinitiator, and has high requirements for color and purity. Currently, activated carbon is often used for decolorization and impurity removal. However, the current decolorization method has the following disadvantages: ① poor selectivity, the activated carbon not only adsorbs pigments but also adsorbs part of the effective components, resulting in a decrease in product yield. ② incomplete decolorization, the removal effect of pigments is limited, and the color of the product is high. ③ limited adsorption capacity, the activated carbon needs to be replaced after saturation, which produces solid waste during production, thereby causing pressure on solid waste treatment. ④ risk of carbon powder residue, improper operation or incomplete filtration can easily cause fine carbon powder to mix into the product, affecting the purity and appearance. SUMMARY

[0004] The purpose of the present application is to provide a decolorization method of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product. The method provided by the present application has good decolorization effect, does not adsorb target components, has high yield, and does not need to use activated carbon, thereby avoiding the risk of solid waste or carbon powder residue.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme:

[0006] The present application provides a decolorization method of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product, which comprises the following steps:

[0007] Mixing an alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product, water and a reducing decolorizing agent to perform reduction decolorization, and obtaining an organic phase.

[0008] Crystallizing the organic phase after impurity removal to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone pure product.

[0009] Preferably, the reducing decoloring agent comprises one or more of sodium thiosulfate, sodium borohydride, sodium dithionite, sulfur dioxide hydride and zinc powder.

[0010] Preferably, the molar amount of the reducing decoloring agent is 2-15% of the molar amount of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone.

[0011] Preferably, the temperature of the reducing decoloring is 50-100℃, and the time of the reducing decoloring is 0.5-3h.

[0012] Preferably, the crystallization is cooling the impurity-removed organic phase to 0-5℃, and stirring for 1h.

[0013] Preferably, the purity of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone is 95-96%, and the impurities in the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone include oxidative impurities, monobutyl-substituted products, residual raw materials and other unknown impurities.

[0014] Preferably, the alcohol solution of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone comprises the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone and alcohol.

[0015] The mass ratio of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone to alcohol is 150-220:100.

[0016] Preferably, the alcohol is n-butanol.

[0017] Preferably, the rate of the cooling is 10℃ / h.

[0018] Preferably, the alcohol solution of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone has a colority of >400.

[0019] The present application selectively reduces the colored substances generated by oxidation in the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone by adding a suitable reducing decoloring agent to the solution of the crude reaction product, which treatment can significantly destroy the colored impurities, thereby greatly improving the colority of the final product to meet the colority standards required by high-purity chemicals and improving the product quality. Moreover, compared with activated carbon decoloring, the method provided by the present application does not cause the active ingredients of the product to be adsorbed by activated carbon, and the product yield is high; at the same time, the method does not use activated carbon, thereby avoiding the risks of solid waste and carbon powder residues. The data of the examples show that the product quality (colority <50, detection content >99%) after decoloring is significantly better than that of the activated carbon decoloring method. DETAILED DESCRIPTION

[0020] The present application provides a method for decolorizing 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product, comprising the following steps:

[0021] Mixing alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product, water and reducing decoloring agent to perform reducing decoloring to obtain organic phase;

[0022] Crystallizing the organic phase after removing impurities to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone pure product.

[0023] The present application mixes alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product, water and reducing decoloring agent to perform reducing decoloring to obtain organic phase.

[0024] In the present application, the source of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product is preferably prepared by alkylating 2-methyl-1-fluorenyl-2-morpholino-1-propanone and chlorobutane at 70-80℃ for 6h.

[0025] As an embodiment of the present application, the alcohol in the alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product can be n-butanol.

[0026] As an embodiment of the present application, the alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product is obtained by mixing 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product and n-butanol; the colority (platinum-cobalt colorimetric method) of the alcohol solution of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product can be >400.

[0027] The temperature of the mixing can be 50-100℃; the purity of the 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product can be 95%-96%, and the 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product contains 4-5% of oxidized impurities, monobutyl substitution product, residual raw material and other unknown impurities; the mass ratio of the 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product and alcohol can be 150-220:100, specifically 150:100, 180:100, 200:100 or 220:100.

[0028] As an embodiment of the present application, the reducing decoloring agent can include one or several of sodium thiosulfate, sodium borohydride, sodium dithionite, sulfur dioxide hydride and zinc powder. As an embodiment of the present application, the molar amount of the reducing decoloring agent can be 2-15% of the molar amount of the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone, specifically 2%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%.

[0029] As an embodiment of the present application, the temperature of the reducing decoloring can be 50-100℃, specifically 70-80℃; the time of the reducing decoloring can be 0.5-3h, specifically 0.5h, 1h, 1.5h, 2h or 3h.

[0030] After obtaining the organic phase, the present application crystallizes the organic phase after impurity removal to obtain the pure 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone.

[0031] As an embodiment of the present application, the impurity removal method can include washing and membrane filtration in sequence; the pore size of the membrane can be 0.45μm.

[0032] In the present application, the washing can remove metal ions and the filtration can remove insoluble substances.

[0033] As an embodiment of the present application, the crystallization is cooling the impurity-removed organic phase to 0-5℃ and stirring for 1h. As an embodiment of the present application, the cooling rate is 10℃ / h.

[0034] As an embodiment of the present application, after the crystallization, it further includes filtration and drying in sequence.

[0035] In order to further illustrate the present application, the schemes of the present application are described in detail below in combination with examples, but they should not be understood as limiting the scope of protection of the present application.

[0036] Example 1

[0037] 2-methyl-1-fluorenyl-2-morpholino-1-propanone, chlorobutane (the molar ratio of 2-methyl-1-fluorenyl-2-morpholino-1-propanone and chlorobutane is 1:4) are subjected to alkylation reaction at 70℃ for 6h in sodium hydroxide solution, the obtained reaction liquid is separated into phases, the organic phase is washed with water and concentrated to obtain the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone (the content of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone is 95.6%).

[0038] Preparation of crude product solution: In a 500 mL four-necked flask, 200 g of n-butanol was added, followed by the addition of 100 g (230 mmol) of crude 2-methyl-l-(9.9-dibutylfluorenyl)-2-morpholino-l-propanone having a content of 95.6%, which was stirred to dissolve at 80°C, and the colority of the solution was measured to be 454.

[0039] Decolorization: To the solution, 20 g of deionized water was added, followed by the addition of 1.2 g of sulfurous acid hydride (11 mmol), and the solution was stirred to reduce and decolorize at 80°C for 1 h, and the colority of the organic phase was measured to be 73. The solution was allowed to stand to separate into two phases, the aqueous layer was discarded, the organic phase was washed with 30 g of deionized water twice, and the organic phase was filtered using a 0.45 μm filter membrane to remove insoluble matter.

[0040] Crystallization: The solution was slowly cooled to 0°C at a rate of 10°C per hour, and the solution was stirred to crystallize for 1 h, and then filtered and dried to obtain 93.3 g of 2-methyl-l-(9.9-dibutylfluorenyl)-2-morpholino-l-propanone, which was measured to have a content of 99.3% and a colority of 43.

[0041] Example 2

[0042] The 2-methyl-l-fluorenyl-2-morpholino-l-propanone and chlorobutane (the molar ratio of 2-methyl-l-fluorenyl-2-morpholino-l-propanone to chlorobutane was 1:4) were subjected to an alkylation reaction at 70°C for 6 h in a sodium hydroxide solution, and the resulting reaction solution was separated into two phases, and the organic phase was washed with water and concentrated to obtain crude 2-methyl-l-(9.9-dibutylfluorenyl)-2-morpholino-l-propanone (2-methyl-l-(9.9-dibutylfluorenyl)-2-morpholino-l-propanone had a content of 95.23%).

[0043] Preparation of crude product solution: In a 500 mL four-necked flask, 200 g of n-butanol was added, followed by the addition of 100 g (230 mmol) of crude 2-methyl-l-(9.9-dibutylfluorenyl)-2-morpholino-l-propanone having a content of 95.6%, which was stirred to dissolve at 80°C, and the colority of the solution was measured to be 454.

[0044] Decolorization: To the solution, 20 g of deionized water was added, followed by the addition of 1.2 g of sulfurous acid hydride (11 mmol), and the solution was stirred to reduce and decolorize at 80°C for 1 h, and the colority of the organic phase was measured to be 73. The solution was allowed to stand to separate into two phases, the aqueous layer was discarded, the organic phase was washed with 30 g of deionized water twice, and the organic phase was filtered using a 0.45 μm filter membrane to remove insoluble matter.

[0045] Crystallization: The solution was slowly cooled to 3°C at a rate of 10°C per hour, stirred for 1 hour, filtered, and dried to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone 94.1 g. The product was tested (purity was tested by liquid chromatography, and color was tested by the platinum-cobalt colorimetric method), and the content was 99.24%, and the color was 48.

[0046] Example 3

[0047] The 2-methyl-1-fluorenyl-2-morpholino-1-propanone and chlorobutane (the molar ratio of 2-methyl-1-fluorenyl-2-morpholino-1-propanone to chlorobutane was 1:4) were subjected to an alkylation reaction at 80°C for 6 hours in a sodium hydroxide solution. The obtained reaction solution was separated into organic and aqueous phases, and the organic phase was washed with water and concentrated to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product (the content of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone was 95.87%).

[0048] Crude product solution preparation: In a 500 mL four-necked flask, 180 g of n-butanol was added, followed by 100 g (230 mmol) of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product with a content of 95.87%. The solution was dissolved by stirring at 90°C, and the color of the solution was tested to be 436.

[0049] Decolorization: 20 g of deionized water was added to the solution, followed by 1.7 g of sodium hydrosulfite (10 mmol). The solution was stirred and reduced at 90°C for 2.5 hours, and the color of the organic phase was tested to be 70. The solution was allowed to stand and separate into an aqueous phase and an organic phase. The aqueous phase was discarded, and the organic phase was washed twice with 20 g of deionized water. The organic phase was filtered using a 0.45 μm filter membrane to remove insoluble substances.

[0050] Crystallization: The solution was slowly cooled to 5°C at a rate of 10°C per hour, stirred for 1 hour, filtered, and dried to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone 92.5 g. The product was tested (purity was tested by liquid chromatography, and color was tested by the platinum-cobalt colorimetric method), and the content was 99.51%, and the color was 40.

[0051] Example 4

[0052] The 2-methyl-1-fluorenyl-2-morpholinyl-1-propanone, chlorobutane (molar ratio of 2-methyl-1-fluorenyl-2-morpholinyl-1-propanone and chlorobutane is 1:4) were alkylated under the condition of sodium hydroxide solution at 75°C for 6h, the obtained reaction solution was separated into phases, the organic phase was washed with water and concentrated to obtain the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone (2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone content is 95.55%).

[0053] Preparation of crude product solution: 220g of n-butanol was added into a 500mL four-necked flask, then 100g (230mmol) of crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone with a content of 95.55% was added, and the solution was dissolved by stirring at 70°C, and the colority of the solution was detected to be 429.

[0054] Decolorization: 15g of deionized water was added to the solution, and then 0.2g of sodium borohydride (5mmol) was added, and the solution was reduced and decolorized by stirring at 70°C for 1.5h, and the colority of the organic phase was detected to be 72, the solution was allowed to stand and separate into phases, the water layer was discarded, the organic phase was washed with 20g of deionized water for 2 times, and the organic phase was filtered with a 0.45μm filter membrane to remove insoluble substances.

[0055] Crystallization: the solution was slowly cooled to 5°C at a rate of 10°C per hour, and the solution was stirred for 1h to crystallize, and then filtered and dried to obtain 91.2g of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone, and the product was detected (purity was detected by liquid chromatography, and colority was detected by platinum-cobalt colorimetry), the content was 99.25%, and the colority was 44.

[0056] Example 5

[0057] The 2-methyl-1-fluorenyl-2-morpholinyl-1-propanone, chlorobutane (molar ratio of 2-methyl-1-fluorenyl-2-morpholinyl-1-propanone and chlorobutane is 1:4) were alkylated under the condition of sodium hydroxide solution at 75°C for 6h, the obtained reaction solution was separated into phases, the organic phase was washed with water and concentrated to obtain the crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone (2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone content is 95.55%).

[0058] Preparation of crude product solution: 220g of n-butanol was added into a 500mL four-necked flask, then 100g (230mmol) of crude 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholinyl-1-propanone with a content of 95.55% was added, and the solution was dissolved by stirring at 70°C, and the colority of the solution was detected to be 429.

[0059] Decolorization: 2.26 g of zinc powder (35 mmol) was added to the solution, and then 8 g of concentrated hydrochloric acid was slowly added dropwise. After the dropwise addition was completed, the reduction and decolorization were stirred at 60°C for 3 h. The organic phase was detected to have a colority of 70. The solution was allowed to stand and separate into two phases. The water layer was discarded, and the organic phase was washed twice with 40 g of deionized water. The organic phase was filtered using a 0.45 μm filter membrane to remove insoluble substances.

[0060] Crystallization: The solution was slowly cooled to 5°C at a rate of 10°C per hour, stirred for 1 h, filtered, and dried to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone 92.8 g. The product was detected to have a purity of 99.4% and a colority of 41.

[0061] Comparative Example 1

[0062] 2-methyl-1-fluorenyl-2-morpholino-1-propanone and chlorobutane (the molar ratio of 2-methyl-1-fluorenyl-2-morpholino-1-propanone to chlorobutane was 1:4) were subjected to an alkylation reaction at 80°C for 6 h in a sodium hydroxide solution. The obtained reaction solution was separated into two phases. The organic phase was washed with water and concentrated to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product (2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone had a content of 95.79%).

[0063] Crude product solution preparation: In a 500 mL four-necked flask, 200 g of n-butanol was added, followed by 100 g (230 mmol) of 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone crude product having a content of 95.79%. The solution was dissolved by stirring at 60°C. The solution was detected to have a colority of 453.

[0064] Decolorization: 1.5 g of activated carbon was added to the solution. The solution was stirred at 60°C for 3 h to decolorize. Then, the solution was filtered using a 0.45 μm filter membrane to remove the activated carbon. The solution was detected to have a colority of 140.

[0065] Crystallization: The solution was slowly cooled to 5°C at a rate of 10°C per hour, stirred for 1 h, filtered, and dried to obtain 2-methyl-1-(9.9-dibutylfluorenyl)-2-morpholino-1-propanone 87.6 g. The product was detected to have a content of 98.8% and a colority of 98.

[0066] Although the above examples have been described in detail, they are only some examples of the present application, not all examples. Other examples can be obtained according to the above examples without creativity, and these examples also belong to the protection scope of the present application.

Claims

1. A method for decolorizing crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholinyl-1-propanone, comprising the following steps: An alcoholic solution of crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholinyl-1-propanone, water, and a reducing decolorizing agent were mixed and subjected to reduction decolorization to obtain an organic phase. After removing impurities from the organic phase, crystallization yielded pure 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone.

2. The decolorization method as described in claim 1, characterized in that, The reducing decolorizing agent includes one or more of sodium thiosulfate, sodium borohydride, sodium dithionite, thiourea dioxide, and zinc powder.

3. The decolorization method as described in claim 1, characterized in that, The molar amount of the reducing decolorizing agent is 2 to 15% of the molar amount of the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone.

4. The decolorization method as described in claim 1, characterized in that, The reduction and decolorization temperature is 50–100°C, and the reduction and decolorization time is 0.5–3 hours.

5. The decolorization method as described in claim 1, characterized in that, The crystallization process involves cooling the purified organic phase to 0–5°C and stirring to grow crystals for 1 hour.

6. The decolorization method as described in claim 1, characterized in that, The purity of the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone is 95% to 96%; the impurities in the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone include oxidative impurities, monobutyl-substituted products, residual raw materials and other unknown impurities.

7. The decolorization method as described in claim 1, characterized in that, The alcoholic solution of the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholinyl-1-propanone comprises the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholinyl-1-propanone and an alcohol; The mass ratio of the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone to the alcohol is 150-220:

100.

8. The decolorization method as described in claim 7, characterized in that, The alcohol is n-butanol.

9. The decolorization method as described in claim 5, characterized in that, The cooling rate is 10℃ / h.

10. The decolorization method as described in claim 1, characterized in that, The color of the alcoholic solution of the crude 2-methyl-1-(9,9-dibutylfluorenyl)-2-morpholino-1-propanone is >400.