The invention relates to a method for preparing 3, 3apos; process for the preparation of-[1, 4-butylbis (oxymethylene)]-bis-(3-ethyl) oxetane

Abstract

The invention provides a method for preparing 3, 3 '-[1, 4-butyl bis (oxymethylene)]-bis-(3-ethyl) oxetane. The invention relates to a conversion process for preparing 3, 3 '-[1, 4-butyl bis (oxymethylene)]-bis-(3-ethyl) oxetane through a reaction between 3-ethyl-3-oxetane methanol and 1, 4-dichlorobutane by taking 3-ethyl-3-oxetane as a raw material, taking potassium hydroxide as an alkaline reagent and adopting a quaternary ammonium salt or quaternary phosphonium salt phase transfer catalyst. Compared with the prior art, the method has the advantages that the reaction is promoted by dropwise adding the 1, 4-dichlorobutane and distilling the water while dropwise adding the 1, 4-dichlorobutane, the product with higher content and lower color number can be obtained without distilling the product, and compared with the traditional one-pot method, the production efficiency, the product yield and the purity are improved, the color number of the product is reduced, and the method is suitable for industrial mass production.

Description

Technical Field

[0001] The invention relates to a method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane, belonging to the technical field of organic synthesis. Background Art

[0002] The molecular structure of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane (CAS: 126050-33-7) contains two epoxyoxetanes. The ring tension of the epoxy group makes it easy to react with various nucleophilic groups. In addition, the resin composition containing the oxetane compound as a component has small shrinkage during curing and can be used as a monomer in a photocurable cationic system. It is used in the fields of photocurable inks, coatings, adhesives, etc. It has the characteristics of good dilution, fast crosslinking speed, and excellent performance after film formation, making it one of the raw materials with the most market potential in the field of cationic photocuring.

[0003] Common synthesis methods for 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane include phase transfer catalytic one-step synthesis, etherification-ring closure, enzyme catalytic synthesis, etc. Among them, the one-step synthesis method has relatively mild reaction conditions, is easy to operate, has less pollution, and the catalyst is common and easy to obtain. It is currently the most commonly used synthesis process. In the traditional one-step synthesis method, since the reaction system is a liquid-solid heterogeneous phase, mass transfer is difficult, resulting in incomplete reaction, long reaction time, low yield, and excessive solid base, which is easy to produce other impurities, resulting in waste of raw materials, low product purity, more by-products, and high color number.

[0004] At present, many processes have improved the phase transfer catalytic one-step synthesis method, and these improvements focus more on the reaction temperature and the type of phase transfer catalyst. However, the improvement of the process route will further improve the reaction efficiency, reduce the occurrence of background reactions, improve the purity of the product, and reduce the product color number. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the shortcomings of low product purity, high time cost, more by-products, low yield and high color number in the traditional phase transfer catalytic one-step synthesis method. Potassium hydroxide is used as a base, a phase transfer catalyst is used at the same time, 1,4-dichlorobutane is added dropwise while reacting, and water is removed by the solvent to promote the reaction. While reducing the occurrence of side reactions, efficient conversion of raw materials is achieved to obtain high-purity products.

[0006] The invention discloses a method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane, comprising the following steps: using 3-ethyl-3-oxetane methanol and 1,4-dichlorobutane as raw materials, reacting in an organic solvent in the presence of a solid base and a phase transfer catalyst to obtain 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane.

[0007] Furthermore, in the above technical solution, the solid base is selected from sodium hydroxide or potassium hydroxide.

[0008] Furthermore, in the above technical solution, the phase transfer catalyst is selected from tetrabutylammonium bromide, triethylbenzylammonium bromide, tetramethylammonium chloride, tetrabutylammonium chloride, polyethylene glycol or 18-crown ether-6.

[0009] Furthermore, in the above technical solution, the reaction temperature is 90-120° C., and the reaction time is 5-40 hours.

[0010] Furthermore, in the above technical solution, the organic solvent is selected from n-heptane, toluene, cyclohexane or dioxane.

[0011] Furthermore, in the above technical solution, the molar ratio of 1,4-dichlorobutane, 3-ethyl-3-oxetanol, solid base and phase transfer catalyst is 1:2-3:3-10:0.005-0.1.

[0012] Furthermore, in the above technical solution, during the reaction, the generated water is removed while the reaction is taking place, so as to promote the reaction to proceed continuously toward the product. Specifically, 1,4-dichlorobutane is added dropwise while the reaction is taking place, and then the reaction is promoted by bringing water with the solvent.

[0013] Furthermore, in the above technical scheme, after the reaction is completed, the filtrate is filtered and water is added to the filtrate to remove a small amount of dissolved solid alkali and chloride salt; after stratification, the organic phase is distilled at atmospheric pressure to recover the solvent, and the residual solvent and high-boiling impurities are distilled under reduced pressure at 60-170°C / 4-12mmHg by an oil pump, and the kettle residue is 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane.

[0014] Furthermore, in the above technical solution, during the distillation process, the distillation stage is divided into two processes: recovering the solvent at normal pressure and removing the small amount of residual solvent and high-boiling impurities in the system at reduced pressure.

[0015] Furthermore, in the above technical solution, the excess solvent recovered in the atmospheric distillation stage is reused.

[0016] Furthermore, in the above technical solution, the typical operating reaction equation is expressed as follows:

[0017]

[0018] Potassium hydroxide, 3-ethyl-3-oxabutane methanol, catalyst and organic solvent are added to a reactor with a water separator and mechanical stirring, and 1,4-dichlorobutane is slowly added to it using a constant pressure dropping funnel and stirred vigorously. Water is separated while dropping, and after the addition of 1,4-dichlorobutane is completed, the water separation is continued for 10-30 hours of insulation. After the reaction is completed, filter and add an appropriate amount of water to remove a small amount of potassium chloride and potassium hydroxide generated by the dissolved reaction. At this time, the organic phase is on the upper layer and the aqueous phase is on the lower layer. Separate the organic phase, extract the aqueous phase with solvent, recover the solvent by atmospheric distillation, and then use an oil pump 4-12mmHg / 60-170℃ to perform high vacuum decompression distillation to remove residual solvents and high-boiling impurities, and obtain a high-purity and low-color product in the kettle residue.

[0019] Beneficial effects of the present invention

[0020] A. Through the dropwise addition and water separation operations, the generation of side reactions is reduced, the temperature is stable, and the reaction is mild.

[0021] B. After the reaction is completed, the solvent can be recycled and reused multiple times; by distilling the solvent, a high-purity transparent product with a low color number can be obtained without evaporating the product, and the process is easy to operate and the steps are simple, which is suitable for workshop production. DETAILED DESCRIPTION

[0022] The following examples will be used to illustrate the embodiments of the present invention, which do not limit the protection scope of the present invention. The phase transfer catalysts used in the examples: tetrabutylammonium bromide, tetramethylammonium chloride, tetrabutylammonium chloride, 18-crown ether-6 were purchased from the market.

[0023] Example 1

[0024] Add 252g (4.5mol) of KOH, 2.2g (0.02mol) of tetramethylammonium chloride and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 500g (5mol) of n-heptane, raise the temperature to 110℃, and keep the internal temperature at about 100℃. Add 127g (1mol) of 1,4-dichlorobutane dropwise, and use a water separator to separate water while adding dropwise. The reaction is completed in 2h, and then the reaction is kept warm for 15h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of n-heptane was used to rinse the filter cake, 150 g of water was used to wash 3 times, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined and concentrated, and the n-heptane was removed by atmospheric distillation at 110-150 ° C. The residual n-heptane and high-boiling impurities were removed by oil pump decompression at 60-170 ° C. The kettle residue obtained 243 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane with a content of 95.2%, a yield of 85%, and a color number of 25.

[0025] Example 2

[0026] Add 252g (4.5mol) of KOH, 6.44g (0.02mol) of tetrabutylammonium bromide and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 500g (5mol) of n-heptane, raise the temperature to 110℃, and keep the internal temperature at about 100℃. Add 127g (1mol) of 1,4-dichlorobutane dropwise, and use a water separator to separate water while adding dropwise. The reaction is completed in 2h, and then the temperature is kept for 15h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of n-heptane was used to rinse the filter cake, 150 g of water was used to wash 3 times, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined and concentrated, and the n-heptane was removed by atmospheric distillation at 110-150 ° C. The residual n-heptane and high-boiling impurities were removed by oil pump decompression at 60-170 ° C. The kettle residue obtained 230 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane with a content of 92.8%, a yield of 80.4%, and a color number of 45.

[0027] Example 3

[0028] Add 252g (4.5mol) of KOH, 5.56g (0.02mol) of tetrabutylammonium chloride and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 500g (5mol) of n-heptane, raise the temperature to 110℃, and keep the internal temperature at about 100℃. Add 127g (1mol) of 1,4-dichlorobutane dropwise, and use a water separator to separate water while adding dropwise. The reaction is completed in 2h, and then the temperature is kept for 15h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of n-heptane was used to wash the filter cake, 150 g of water was used to wash 3 times, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined, and the mixture was concentrated. The n-heptane was removed by atmospheric distillation at 110-150°C, and the residual n-heptane and high-boiling impurities were removed by oil pump decompression at 60-170°C. 228 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane was obtained from the kettle residue, with a content of 94.1%, a yield of 79.7%, and a color number of 30.

[0029] Example 4

[0030] Add 252g (4.5mol) of KOH, 5.3g (0.02mol) of 18-crown-6 and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 500g (5mol) of n-heptane, raise the temperature to 110℃, and keep the internal temperature at about 100℃. Add 127g (1mol) of 1,4-dichlorobutane dropwise, and use a water separator to separate water while adding dropwise. The dripping is completed in 2h, and then the temperature is kept for 20h. After the reaction was completed, the temperature was lowered, the filter cake was filtered, 80 g of n-heptane was used to rinse the filter cake, 150 g of water was used to wash 3 times, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined, and the mixture was concentrated. The n-heptane was removed by atmospheric distillation at 110-150 ° C. The residual n-heptane and high-boiling impurities were removed by oil pump decompression at 60-170 ° C. The kettle residue obtained 143 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane with a content of 90.1%, a yield of 50%, and a color number of 30.

[0031] Example 5

[0032] Add 252g (4.5mol) of KOH, 2.2g (0.02mol) of tetramethylammonium chloride and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 460g (5mol) of toluene, raise the temperature to 120℃, and the internal temperature to about 110℃, and drop 127g (1mol) of 1,4-dichlorobutane, while adding dropwise and reacting with a water separator, and the dripping is completed in 2h, and then continue to keep warm for 10h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of toluene was used to wash the filter cake, 150 g of water was used to wash 3 times, 150 g of toluene was used to extract the aqueous phase, the layers were separated, the organic phases were combined and concentrated, and the toluene was removed by atmospheric distillation at 120-150 ° C. The residual toluene and high-boiling impurities were removed by oil pump decompression at 60-170 ° C. The kettle residue obtained 231 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane with a content of 93.1%, a yield of 80.8%, and a color number of 35.

[0033] Example 6

[0034] Add 252g (4.5mol) of KOH, 2.2g (0.02mol) of tetramethylammonium chloride and 290g (2.5mol) of 3-ethyl-3-oxabutane methanol into a four-necked flask equipped with a stirrer. Start stirring, add 420g (5mol) of cyclohexane, raise the temperature to 90℃, and the internal temperature to about 80℃, then drop 127g (1mol) of 1,4-dichlorobutane, and use a water separator to separate water while adding dropwise. The dripping is completed in 2h, and then the temperature is kept for 20h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of cyclohexane was used to rinse the filter cake, 150 g of water was used to wash 3 times, 150 g of cyclohexane was used to extract the aqueous phase, the layers were separated, the organic phases were combined and concentrated, and the cyclohexane was removed by atmospheric distillation at 90-150 ° C. The residual cyclohexane and high-boiling impurities were removed by oil pump decompression at 60-170 ° C. The kettle residue obtained 240 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane with a content of 94.8%, a yield of 83.9%, and a color number of 20.

[0035] Example 7

[0036] Add 252g KOH (4.5mol) and 252g water to a four-necked flask equipped with a stirrer to prepare a 50% KOH aqueous solution, then add 2.2g tetramethylammonium chloride (0.02mol) and 3-ethyl-3-oxabutane methanol (290g, 2.5mol). Start stirring, raise the temperature to 90℃, and the internal temperature to about 80℃, then drop 1,4-dichlorobutane 127g (1mol), react while dropping, and finish dropping in 2h, then continue to keep warm for 5h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of cyclohexane was used to rinse the filter cake, 150 g of water was used to wash 3 times, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined, and the concentration was carried out. The n-heptane was removed by atmospheric distillation at 100-150 ° C. The residual cyclohexane and high-boiling impurities were removed by oil pump decompression at 60-170 ° C., and 190 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane was obtained from the kettle residue, with a content of 89.6%, a yield of 72%, and a color number of 40.

[0037] Example 8

[0038] Add 252g (4.5mol) of KOH, 2.2g (0.02mol) of tetramethylammonium chloride and 127g (1mol) of 1,4-dichlorobutane to a four-necked flask equipped with a stirrer. Start stirring, add 500g (5mol) of n-heptane, raise the temperature to 110°C, and keep the internal temperature at about 100°C. Add 3-ethyl-3-oxetane methanol (290g, 2.5mol) dropwise, and use a water separator to separate water while adding dropwise. The reaction is completed after 3 hours of dripping, and then the temperature is kept for 18 hours. The reaction is finished. Cool down, filter, wash the filter cake with 80g n-heptane, wash with 150g water*3, extract the aqueous phase with 150g n-heptane, separate the layers, combine the organic phases, concentrate, remove n-heptane by atmospheric distillation at 110-150℃, remove residual n-heptane and high-boiling impurities by oil pump decompression at 60-170℃, and obtain 214g 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane from the kettle residue, with a content of 93.8%, a yield of 74.8%, and a color number of 25.

[0039] Example 9

[0040] In a four-necked flask equipped with a stirrer, 180 g (4.5 mol) of NaOH, 2.2 g (0.02 mol) of tetramethylammonium chloride and 290 g (2.5 mol) of 3-ethyl-3-oxetanol were added, stirring was started, 500 g (5 mol) of n-heptane was added, the temperature was raised to 110°C, the internal temperature was about 100°C, 127 g (1 mol) of 1,4-dichlorobutane was added dropwise, and the reaction was carried out dropwise while using a water separator to separate the water. The dropping was completed in 2 h, and then the temperature was kept warm for 15 h. After the reaction was completed, the temperature was lowered, the filter was filtered, 80 g of n-heptane was used to wash the filter cake, 150 g of water*3 was used to wash, the aqueous phase was extracted with 150 g of n-heptane, the layers were separated, the organic phases were combined, and the mixture was concentrated. The n-heptane was removed by atmospheric distillation at 110-150°C, and the residual n-heptane and high-boiling impurities were removed by oil pump decompression at 60-170°C. 220 g of 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane was obtained from the kettle residue, with a content of 91.8%, a yield of 77%, and a color number of 25.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane, characterized in that: The method comprises the following steps: taking 3-ethyl-3-oxetane methanol and 1,4-dichlorobutane as raw materials, reacting in an organic solvent in the presence of a solid base and a phase transfer catalyst to obtain 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane.

2. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: The solid base is selected from sodium hydroxide or potassium hydroxide.

3. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: The phase transfer catalyst is selected from tetrabutylammonium bromide, triethylbenzylammonium bromide, tetramethylammonium chloride, tetrabutylammonium chloride, polyethylene glycol or 18-crown ether-6.

4. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: The reaction temperature is 90-120°C, and the reaction time is 5-40 hours.

5. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: The organic solvent is selected from n-heptane, toluene, cyclohexane or dioxane.

6. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: The molar ratio of the 1,4-dichlorobutane, 3-ethyl-3-oxetanol, solid base and phase transfer catalyst is 1:2-3:3-10:0.005-0.

1.

7. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: During the reaction, the generated water is removed while the reaction is taking place, thereby promoting the reaction to proceed toward the product.

8. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 1, characterized in that: After the reaction is completed, the mixture is filtered and water is added to the filtrate to remove a small amount of dissolved solid alkali and chloride salts. After separation, the organic phase is distilled at atmospheric pressure to recover the solvent. The residual solvent and high-boiling impurities are distilled at 60-170°C / 4-12mmHg under reduced pressure. The residue in the kettle is 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane.

9. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 8, characterized in that: In the distillation process, the distillation stage is divided into two processes: recovering the solvent at normal pressure and removing the small amount of residual solvent and high-boiling impurities in the system at reduced pressure.

10. The method for preparing 3,3'-[1,4-butylbis(oxymethylene)]-bis-(3-ethyl)oxetane according to claim 9, characterized in that: During the atmospheric distillation stage, the excess solvent is recovered and reused.

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