Method for mechanically applying 1, 4-cyclohexanedione neopentyl glycol monoketal byproduct diketal
Through hydrolysis condensation reaction and reduced pressure distillation technology, the problem of 1,4-cyclohexanedione neopentyl glycol biketal is solved, and the production of high-purity monoketal and the recycling of sulfuric acid aqueous solution is realized, thereby improving the Productivity and product purity.
Patent Information
- Application Number
- CN202411395832.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-01-03
AI Technical Summary
In the prior art, 1,4-cyclohexanedione neopentyl glycol biketal is difficult to recycle, mainly because it is similar to the polarity of water, making it difficult to separate through extraction, water washing and crystallization, and is usually used as solid waste. deal with.
Using hydrolysis and condensation reaction, water-insoluble solvents and catalysts were added, and 1,4-cyclohexanedione, monoketal and biketal were separated by decompression distillation, and the yield of high-purity monoketal was achieved by different boiling points, and the yield of high-purity monoketal was achieved. The aqueous sulfuric acid solution was recovered for use in the next batch of reactions.
The effective recycling and utilization of 1,4-cyclohexanedione neopentopentyl glycol biketal was achieved, and the reaction selectivity was improved, and a high-purity 1,4-cyclohexanedione neopentopentyl glycol monoketal was obtained. Reduce pollution and improve production efficiency.
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Figure CN119241491A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for applying a 1,4-cyclohexanedione neopentyl glycol monoketal by-product bisketal. Background Art
[0002] The common preparation method of 1,4-cyclohexanedione monoketal in the industry is to use 1,4-cyclohexanedione and neopentyl glycol as raw materials in an inert solvent (cyclohexane, petroleum ether, etc.), with acidic substances (including phosphoric acid, p-toluenesulfonic acid, acidic resin, solid super acid, potassium hydrogen sulfate, etc.) as catalysts, and control the temperature to obtain the product. In the reaction, there is a large amount of by-product 1,4-cyclohexanedione neopentyl glycol diketal. The general method of recovering diketal is to hydrolyze the diketal, then separate the liquid and wash it with water, and crystallize and recover part of the raw material diketone. Since 1,4-cyclohexanedione and neopentyl glycol have similar polarity, they are both highly water-soluble. After hydrolysis, the product cannot be separated by extraction, washing and crystallization, so the diketal is difficult to recycle and is generally treated as solid waste. In order to make the diketal recyclable and repeatedly used, a method for applying the by-product diketal of 1,4-cyclohexanedione neopentyl glycol monoketal is needed. Summary of the invention
[0003] The invention provides a method for applying 1,4-cyclohexanedione neopentyl glycol monoketal by-product bisketal, which solves the problem in the related art that 1,4-cyclohexanedione neopentyl glycol bisketal is difficult to recycle.
[0004] The technical solution of the present invention is as follows: The present invention provides a method for applying the byproduct bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal, comprising the following steps: S1, using 1,4-cyclohexanedione neopentyl glycol bisketal and 1,4-cyclohexanedione as raw materials, carrying out a hydrolysis condensation reaction under the action of a catalyst solution, adding a non-water-soluble solvent and stirring to obtain a reaction solution; S2. Post-treating the reaction solution to obtain 1,4-cyclohexanedione neopentyl glycol monoketal and 1,4-cyclohexanedione neopentyl glycol bisketal. The 1,4-cyclohexanedione neopentyl glycol bisketal can be used as a raw material for preparing the next batch of 1,4-cyclohexanedione neopentyl glycol monoketal.
[0005] As a further technical solution, the molar ratio of the 1,4-cyclohexanedione neopentyl glycol bisketal to 1,4-cyclohexanedione is 1:1 to 2:1.
[0006] As a further technical solution, the mass ratio of the 1,4-cyclohexanedione neopentyl glycol bisketal to the catalyst solution is 1:2.1-2.5.
[0007] As a further technical solution, the water-insoluble solvent includes one or more of toluene, cyclohexane, and n-heptane. Preferably, the water-insoluble solvent is toluene.
[0008] As a further technical solution, the mass volume ratio of the 1,4-cyclohexanedione to the non-water-soluble solvent is 1 g:7~11 mL.
[0009] As a further technical solution, the stirring temperature is 30-40° C. and the stirring time is 2-3 h.
[0010] As a further technical solution, the catalyst solution is an aqueous sulfuric acid solution; In the aqueous sulfuric acid solution, the mass ratio of concentrated sulfuric acid to water is 1:20-25; The mass fraction of the concentrated sulfuric acid is 95% to 98%; The aqueous sulfuric acid solution can also be recycled and used in the preparation process of the next batch of 1,4-cyclohexanedione neopentyl glycol monoketal.
[0011] As a further technical solution, the temperature of the hydrolysis condensation reaction is 70-90° C. and the time is 1-5 hours.
[0012] As a further technical solution, the post-treatment includes standing liquid separation, concentration, reduced pressure distillation, and drying treatment in sequence.
[0013] As a further technical solution, during the static separation, the upper organic phase is taken and the lower aqueous phase is used for the next batch reaction; Before the concentration, alkali is used to adjust the pH to 7-10; The vacuum distillation is performed in three stages, wherein the first stage collects the fraction before the vacuum distillation temperature is 104°C, the second stage collects the fraction between the vacuum distillation temperature of 104°C and 115°C, and the third stage collects the fraction after the vacuum distillation temperature is 115°C; In the present invention, 1,4-cyclohexanedione, monoketal and diketal are separated by boiling point difference through reduced pressure distillation, the yield is high, the pollution is small, and high-purity monoketal can be obtained.
[0014] An organic solvent is added to the fraction collected in the second stage before the drying treatment for mixing, and the organic solvent is one or more of n-heptane, n-hexane, petroleum ether and cyclohexane.
[0015] The working principle and beneficial effects of the present invention are: In the present invention, 1,4-cyclohexanedione neopentyl glycol bisketal is used as a raw material for preparing 1,4-cyclohexanedione neopentyl glycol monoketal, 1,4-cyclohexanedione neopentyl glycol bisketal is hydrolyzed to obtain 1,4-cyclohexanedione monoketal and neopentyl glycol, the hydrolyzed neopentyl glycol reacts with 1,4-cyclohexanedione to generate 1,4-cyclohexanedione monoketal, and the added non-water-soluble solvent prevents the generated monoketal from undergoing secondary hydrolysis, thereby forming a protective effect, thereby making the reaction have good selectivity, and the finally obtained product 1,4-cyclohexanedione neopentyl glycol bisketal can be applied as a raw material for preparing the next batch of 1,4-cyclohexanedione neopentyl glycol monoketal. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0017] Figure 1 This is the GC gas chromatogram of the reaction solution obtained in Example 8 of the present invention; Figure 2 This is the GC gas chromatogram of the reaction solution obtained in Example 8 of the present invention. DETAILED DESCRIPTION
[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] In the following embodiments: A Tianmei GC7900 gas chromatograph was used to sample and test the reaction solution; The comprehensive yield is calculated using the following formula:
[0020] In the formula, the monoketal is 1,4-cyclohexanedione neopentyl glycol monoketal, the bisketal is 1,4-cyclohexanedione neopentyl glycol bisketal, and the diketone is 1,4-cyclohexanedione.
[0021] Example 1 200 g of deionized water was added to the reaction flask, and 10 g of concentrated sulfuric acid with a mass fraction of 95% was added under stirring to prepare a sulfuric acid aqueous solution. 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually observed to be clear. 400 ml of cyclohexane was added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 1.
[0022] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the upper organic layer to pH = 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 108.4 grams of crude product, and distill the product under reduced pressure, control the pressure to -0.098MPa, collect the fraction before 104°C, and dry to obtain 3.2 grams of 1,4-cyclohexanedione; collect the fraction from 104 to 115°C, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; collect the fraction after 115°C, dry to obtain 49.5 grams of 1,4-cyclohexanedione neopentyl glycol bis ketal and continue to use it for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 42.1 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 grams and a yield of 30.2%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 42.3%.
[0023] Table 1
[0024] Example 2 200 g of deionized water was added to the reaction flask, and 10 g of concentrated sulfuric acid with a mass fraction of 95% was added under stirring to prepare a sulfuric acid aqueous solution. 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually observed to be clear. 400 ml of n-heptane was added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 2.
[0025] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the pH value of the upper organic layer to 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 95.3 grams of crude product, and distill the product under reduced pressure, control the pressure to -0.098MPa, collect the fraction before 104°C, and dry to obtain 1.1 grams of 1,4-cyclohexanedione; collect the fraction from 104 to 115°C, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; collect the fraction after 115°C, dry to obtain 69.3 grams of 1,4-cyclohexanedione neopentyl glycol bis ketal and continue to use it for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 18.9 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 grams and a yield of 13.5%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 21.2%.
[0026] Table 2
[0027] Example 3 100 g of deionized water was added to the reaction flask, and 5 g of concentrated sulfuric acid with a mass fraction of 98% was added under stirring to prepare a sulfuric acid aqueous solution, and 50 g (0.176 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 19.7 g (0.176 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually clear. 140 ml of toluene was added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 3.
[0028] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the pH value of the upper organic layer to 7 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 61.3 grams of crude product, and distill the product under reduced pressure, control the pressure to -0.098MPa, collect the fraction before 104°C, and dry to obtain 2.7 grams of 1,4-cyclohexanedione; collect the fraction from 104 to 115°C, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; collect the fraction after 115°C, dry to obtain 12.3 grams of 1,4-cyclohexanedione neopentyl glycol bis ketal and continue to use it for feeding; add 8 times of n-heptane to the main fraction, heat to dissolve, stir and cool to 10°C, centrifuge, and dry to obtain 41.9 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 69.78 grams and a yield of 60.0%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 74.2%.
[0029] Table 3
[0030] Example 4 100 g of deionized water was added to the reaction flask, and 5 g of concentrated sulfuric acid with a mass fraction of 98% was added under stirring to prepare a sulfuric acid aqueous solution, and 50 g (0.176 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 19.7 g (0.176 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80 ° C, kept warm for 1 hour, and the solid solution was visually observed to be clear. 140 ml of toluene was quickly added from the dropping funnel. The mixture was naturally cooled to 20 ° C under stirring, and stirred for 3 hours to obtain a reaction solution; the reaction solution was sampled and tested, and the results are shown in Table 4.
[0031] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the upper organic layer to pH = 9 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 61.6 grams. The product is subjected to reduced pressure distillation, and the pressure is controlled to be -0.098MPa. The fraction before 104°C is collected and dried to obtain 2.6 grams of 1,4-cyclohexanedione; the fraction between 104 and 115°C is collected, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; the fraction after 115°C is collected, and dried to obtain 12.8 grams of 1,4-cyclohexanedione neopentyl glycol bisketal and continue to be used for feeding; 5 times n-heptane is added to the main fraction, heated to dissolve, stirred and cooled to -10°C, centrifuged, and dried to obtain 42.2 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 69.78 grams and a yield of 60.0%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 74.9%.
[0032] Table 4
[0033] Example 5 200 g of deionized water was added to the reaction flask, and 10 g of concentrated sulfuric acid with a mass fraction of 95% was added under stirring to prepare a sulfuric acid aqueous solution. 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80 ° C. The reaction was kept warm for 5 hours, and the solid solution was visually observed to be clear. 400 ml of toluene was quickly added from the dropping funnel. The mixture was naturally cooled to 40 ° C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 5.
[0034] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the pH value of the upper organic layer to 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 123 grams. The product is subjected to reduced pressure distillation, and the pressure is controlled to be -0.098MPa. The fraction before 104°C is collected and dried to obtain 4.7 grams of 1,4-cyclohexanedione; the fraction between 104 and 115°C is collected, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; the fraction after 115°C is collected, and dried to obtain 23.5 grams of 1,4-cyclohexanedione neopentyl glycol bisketal and continue to be used for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 85.2 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 grams and a yield of 60.0%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 74.2%.
[0035] Table 5
[0036] Example 6 (sulphuric acid aqueous solution applied once) The aqueous phase (i.e., aqueous sulfuric acid solution) obtained by the post-treatment of Example 5 was added to the reaction flask, and 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually observed to be clear. 400 ml of toluene was quickly added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 6.
[0037] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the pH value of the upper organic layer to 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 123 grams. The product is subjected to reduced pressure distillation, and the pressure is controlled to be -0.098MPa. The fraction before 104°C is collected and dried to obtain 6.2 grams of 1,4-cyclohexanedione; the fraction between 104 and 115°C is collected, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; the fraction after 115°C is collected, and dried to obtain 19.8 grams of 1,4-cyclohexanedione neopentyl glycol bisketal and continue to be used for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 84.5 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 grams and a yield of 60.5%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 73.6%.
[0038] Table 6
[0039] Example 7 (sulphuric acid aqueous solution was used twice) The aqueous phase (i.e., aqueous sulfuric acid solution) obtained by post-treatment in Example 6 was added to the reaction flask, and 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added, and the mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually observed to be clear. 400 ml of toluene was quickly added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested, and the results are shown in Table 7.
[0040] Post-treatment: let stand, separate the liquids, the lower layer is the aqueous phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the upper organic layer to pH = 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 123 grams. The product is subjected to reduced pressure distillation, and the pressure is controlled to be -0.098MPa. The fraction before 104°C is collected and dried to obtain 5.6 grams of 1,4-cyclohexanedione; the fraction between 104 and 115°C is collected, which is the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; the fraction after 115°C is collected, and dried to obtain 21.2 grams of 1,4-cyclohexanedione neopentyl glycol bisketal and continue to be used for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 84.1 grams of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 grams and a yield of 60.3%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 73.2%.
[0041] Table 7
[0042] Example 8 (sulphuric acid aqueous solution was applied 3 times) The aqueous phase (i.e., aqueous sulfuric acid solution) obtained by the post-treatment of Example 7 was added to the reaction flask, and 100 g (0.352 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 g (0.352 mol) of 1,4-cyclohexanedione were added. The mixture was heated to 80°C and kept warm for 5 hours. The solid solution was visually clear. 400 ml of toluene was quickly added from the dropping funnel. The mixture was naturally cooled to 40°C under stirring and stirred for 2 hours to obtain a reaction solution. The reaction solution was sampled and tested. The results are shown in Table 8 and Figure 1 As shown in the GC gas chromatogram.
[0043] Post-treatment: let stand, separate the liquids, the lower layer is the water phase (i.e., sulfuric acid aqueous solution) which can be used for the next batch reaction; adjust the upper organic layer to pH = 10 with a small amount of alkali, heat and concentrate until no solvent flows out, and obtain 123 grams. The product is subjected to vacuum distillation, and the pressure is controlled at -0.098MPa. The fractions before 104°C are collected and dried to obtain 5.7 grams of 1,4-cyclohexanedione; the fractions from 104 to 115°C are collected, which are the main fractions 1,4-cyclohexanedione neopentyl glycol monoketal ; Collect the fraction after 115°C, dry to obtain 22.8 g of 1,4-cyclohexanedione neopentyl glycol bisketal and continue to use it for feeding; add n-heptane twice the mass of the main fraction to the main fraction, heat to dissolve, stir and cool to -20°C, centrifuge, and dry to obtain 83.2 g of 1,4-cyclohexanedione neopentyl glycol monoketal, the theoretical amount is 139.56 g, the yield is 59.6%, and the obtained 1,4-cyclohexanedione neopentyl glycol monoketal is sampled and tested as follows Figure 2As shown in the GC gas chromatogram, the content of monoketal is 99.892%, the content of 1,4-cyclohexanedione is 0.010%, and the content of 1,4-cyclohexanedione neopentyl glycol bisketal is 0.026%. After deducting the recovery of 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisketal, the comprehensive yield is 73.2%.
[0044] Table 8
[0045] Example 9 Add 150 liters of deionized water to a 1000 liter enamel kettle, start stirring, slowly add 10 kg of concentrated sulfuric acid from the high-level tank to prepare a sulfuric acid aqueous solution, rinse the pipeline and the high-level tank with 50 liters of deionized water, stop stirring after stirring for 5 minutes, and add 100 kg of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 kg of 1,4-cyclohexanedione from the kettle. Turn on stirring and heating, raise the temperature to 80°C, and keep the temperature to react until the solution is clear (5 hours). Turn off the heating, add 400 liters of toluene from the high-level tank while stirring, cool the circulating water to 40°C, control the temperature at 40°C and stir for 2 hours to obtain a reaction solution; sample the reaction solution for testing, and the results are shown in Table 9.
[0046] Post-treatment: let stand, separate the liquids, and the aqueous phase (i.e., sulfuric acid aqueous solution) can be used for the next batch of reactions. Add 3 kg of organic base to the organic phase until the pH is 9. The organic phase was stirred and heated, refluxed and separated until no water was produced, and the solvent was distilled off at normal pressure to obtain 141.2 kg. The product was distilled under reduced pressure, and the pressure was controlled at -0.098 MPa. The fraction before 104°C was collected and dried to obtain 6.1 kg of 1,4-cyclohexanedione; the fraction between 104 and 115°C was collected, which was the main fraction 1,4-cyclohexanedione neopentyl glycol monoketal; the fraction after 115°C was collected and dried to obtain 20.2 kg of 1,4-cyclohexanedione neopentyl glycol bisketal for further use in feeding; 5 times n-heptane was added to the main fraction, heated to dissolve, stirred and cooled to -10°C, centrifuged, and dried to obtain 84.2 kg of 1,4-cyclohexanedione neopentyl glycol monoketal, with a theoretical amount of 139.56 kg and a yield of 60.3%. After deducting the recovered 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol bisacetal, the overall yield is 73.4%.
[0047] Table 9
[0048] Example 10 The aqueous phase (i.e., aqueous sulfuric acid solution) obtained during the post-treatment of Example 9 was applied, and other materials and post-treatment methods remained unchanged. About 83.2 kg of 1,4-cyclohexanedione neopentyl glycol monoketal was obtained, with a yield of 59.6%; 6.2 kg of 1,4-cyclohexanedione was recovered, and 21.3 kg of 1,4-cyclohexanedione neopentyl glycol bisketal was recovered, with a comprehensive yield of 73.1%.
[0049] Embodiment 11 The aqueous phase (i.e., aqueous sulfuric acid solution) obtained by post-treatment in Example 10 was applied, and other materials and post-treatment methods remained unchanged. About 84.8 kg of 1,4-cyclohexanedione neopentyl glycol monoketal was obtained, with a yield of 60.8%. 5.6 kg of 1,4-cyclohexanedione was recovered, and 22.4 kg of 1,4-cyclohexanedione neopentyl glycol diketal was recovered. The overall yield was 74.4%.
[0050] Example 12 The aqueous phase (i.e., aqueous sulfuric acid solution) obtained by post-treatment in Example 11 was applied, and other materials and post-treatment methods remained unchanged. About 83.6 kg of 1,4-cyclohexanedione neopentyl glycol monoketal was obtained, with a yield of 59.9%. 6.0 kg of 1,4-cyclohexanedione was recovered, and 20.9 kg of 1,4-cyclohexanedione neopentyl glycol diketal was recovered. The overall yield was 73.1%.
[0051] Embodiment 13 The only difference between this embodiment and embodiment 5 is that 480 grams of deionized water is put into the reaction bottle, 20 grams of concentrated sulfuric acid with a mass fraction of 95% is added under stirring to prepare a sulfuric acid aqueous solution, 200 grams (0.704 mol) of 1,4-cyclohexanedione neopentyl glycol bisacetal and 39.4 grams (0.352 mol) of 1,4-cyclohexanedione are added, and the mixture is heated to 80°C and kept warm for 5 hours. The solid solution is visually observed to be clear. 400 milliliters of toluene are quickly added from the dropping funnel. The mixture is naturally cooled to 40°C under stirring and stirred for 3 hours to obtain a reaction solution. The reaction solution is sampled and tested, and the results are shown in Table 10. Theoretical amount: 209.36 g, 54.8 g of 1,4-cyclohexanedione neopentyl glycol monoketal was obtained, with a yield of 26.2%. 2.3 g of 1,4-cyclohexanedione was recovered, and 139.8 g of 1,4-cyclohexanedione neopentyl glycol diketal was recovered and continued to be used for feeding. After deducting the recovery of 1,4-cyclohexanedione and 1,4-cyclohexanedione neopentyl glycol diketal, the comprehensive yield was: 50.8%.
[0052] Table 10
[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for applying 1,4-cyclohexanedione neopentyl glycol monoketal by-product bisketal, characterized in that: The following steps are involved: S1, using 1,4-cyclohexanedione neopentyl glycol bisketal and 1,4-cyclohexanedione as raw materials, carrying out a hydrolysis condensation reaction under the action of a catalyst solution, adding a non-water-soluble solvent and stirring to obtain a reaction solution; S2. Post-treating the reaction solution to obtain 1,4-cyclohexanedione neopentyl glycol monoketal and 1,4-cyclohexanedione neopentyl glycol bisketal. The 1,4-cyclohexanedione neopentyl glycol bisketal can be used as a raw material for preparing the next batch of 1,4-cyclohexanedione neopentyl glycol monoketal.
2. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The molar ratio of the 1,4-cyclohexanedione neopentyl glycol bisketal to 1,4-cyclohexanedione is 1:1 to 2:
1.
3. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The mass ratio of the 1,4-cyclohexanedione neopentyl glycol bisketal to the catalyst solution is 1:2.1-2.
5.
4. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The non-water-soluble solvent includes one or more of toluene, cyclohexane, and n-heptane. Preferably, the water-insoluble solvent is toluene.
5. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 4, characterized in that: The mass volume ratio of the 1,4-cyclohexanedione to the water-insoluble solvent is 1 g:7-11 mL.
6. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The stirring temperature is 30-40° C. and the stirring time is 2-3 h.
7. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The catalyst solution is an aqueous sulfuric acid solution; In the aqueous sulfuric acid solution, the mass ratio of concentrated sulfuric acid to water is 1:20-25; The mass fraction of the concentrated sulfuric acid is 95% to 98%.
8. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The temperature of the hydrolysis condensation reaction is 70-90° C. and the time is 1-5 hours.
9. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 1, characterized in that: The post-treatment includes standing liquid separation, concentration, reduced pressure distillation and drying treatment in sequence.
10. The method for applying the by-product bisketal of 1,4-cyclohexanedione neopentyl glycol monoketal according to claim 9, characterized in that: During the standing liquid separation, the upper organic phase is taken and the lower aqueous phase is used for the next batch reaction; Before the concentration, alkali is used to adjust the pH to 7-10; The vacuum distillation is performed in three stages, wherein the first stage collects the fraction before the vacuum distillation temperature is 104°C, the second stage collects the fraction between the vacuum distillation temperature of 104°C and 115°C, and the third stage collects the fraction after the vacuum distillation temperature is 115°C; An organic solvent is added to the fraction collected in the second stage before the drying treatment for mixing, and the organic solvent is one or more of n-heptane, n-hexane, petroleum ether and cyclohexane.