CN115181016A - Synthetic method of dibenzoyl methane - Google Patents
Synthetic method of dibenzoyl methane Download PDFInfo
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- CN115181016A CN115181016A CN202210583490.7A CN202210583490A CN115181016A CN 115181016 A CN115181016 A CN 115181016A CN 202210583490 A CN202210583490 A CN 202210583490A CN 115181016 A CN115181016 A CN 115181016A
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- dibenzoylmethane
- enamine
- benzoyl chloride
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- NZZIMKJIVMHWJC-UHFFFAOYSA-N dibenzoylmethane Chemical compound C=1C=CC=CC=1C(=O)CC(=O)C1=CC=CC=C1 NZZIMKJIVMHWJC-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 238000010189 synthetic method Methods 0.000 title description 2
- 238000006243 chemical reaction Methods 0.000 claims abstract description 75
- RWRDLPDLKQPQOW-UHFFFAOYSA-N Pyrrolidine Chemical compound C1CCNC1 RWRDLPDLKQPQOW-UHFFFAOYSA-N 0.000 claims abstract description 63
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims abstract description 63
- FYSNRJHAOHDILO-UHFFFAOYSA-N thionyl chloride Chemical compound ClS(Cl)=O FYSNRJHAOHDILO-UHFFFAOYSA-N 0.000 claims abstract description 44
- KWOLFJPFCHCOCG-UHFFFAOYSA-N Acetophenone Chemical compound CC(=O)C1=CC=CC=C1 KWOLFJPFCHCOCG-UHFFFAOYSA-N 0.000 claims abstract description 38
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 claims abstract description 35
- 238000000034 method Methods 0.000 claims abstract description 35
- 150000002081 enamines Chemical class 0.000 claims abstract description 31
- PASDCCFISLVPSO-UHFFFAOYSA-N benzoyl chloride Chemical compound ClC(=O)C1=CC=CC=C1 PASDCCFISLVPSO-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000005711 Benzoic acid Substances 0.000 claims abstract description 17
- 235000010233 benzoic acid Nutrition 0.000 claims abstract description 17
- 230000002194 synthesizing effect Effects 0.000 claims abstract description 14
- 238000002360 preparation method Methods 0.000 claims abstract description 11
- 238000006555 catalytic reaction Methods 0.000 claims abstract description 6
- JOXIMZWYDAKGHI-UHFFFAOYSA-N toluene-4-sulfonic acid Chemical compound CC1=CC=C(S(O)(=O)=O)C=C1 JOXIMZWYDAKGHI-UHFFFAOYSA-N 0.000 claims abstract description 6
- 238000005903 acid hydrolysis reaction Methods 0.000 claims abstract description 5
- 238000003379 elimination reaction Methods 0.000 claims abstract description 4
- 230000000269 nucleophilic effect Effects 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 230000035484 reaction time Effects 0.000 claims description 12
- 238000004821 distillation Methods 0.000 claims description 9
- 238000010992 reflux Methods 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 7
- 238000001816 cooling Methods 0.000 claims description 2
- 239000002904 solvent Substances 0.000 abstract description 11
- 239000002351 wastewater Substances 0.000 abstract description 8
- 238000007086 side reaction Methods 0.000 abstract description 4
- 238000004065 wastewater treatment Methods 0.000 abstract description 4
- 239000002253 acid Substances 0.000 abstract description 3
- 238000012545 processing Methods 0.000 abstract description 2
- 150000003839 salts Chemical class 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 32
- 230000000052 comparative effect Effects 0.000 description 25
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 18
- NQRYJNQNLNOLGT-UHFFFAOYSA-N Piperidine Chemical compound C1CCNCC1 NQRYJNQNLNOLGT-UHFFFAOYSA-N 0.000 description 13
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 12
- YNAVUWVOSKDBBP-UHFFFAOYSA-N Morpholine Chemical compound C1COCCN1 YNAVUWVOSKDBBP-UHFFFAOYSA-N 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 239000002994 raw material Substances 0.000 description 10
- 230000006872 improvement Effects 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000002474 experimental method Methods 0.000 description 6
- 150000003335 secondary amines Chemical class 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 4
- QPJVMBTYPHYUOC-UHFFFAOYSA-N methyl benzoate Chemical compound COC(=O)C1=CC=CC=C1 QPJVMBTYPHYUOC-UHFFFAOYSA-N 0.000 description 4
- 239000008399 tap water Substances 0.000 description 4
- 235000020679 tap water Nutrition 0.000 description 4
- -1 DBM sodium salt Chemical class 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- YFKBXYGUSOXJGS-UHFFFAOYSA-N 1,3-Diphenyl-2-propanone Chemical compound C=1C=CC=CC=1CC(=O)CC1=CC=CC=C1 YFKBXYGUSOXJGS-UHFFFAOYSA-N 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 2
- KXDAEFPNCMNJSK-UHFFFAOYSA-N Benzamide Chemical compound NC(=O)C1=CC=CC=C1 KXDAEFPNCMNJSK-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- NQTADLQHYWFPDB-UHFFFAOYSA-N N-Hydroxysuccinimide Chemical compound ON1C(=O)CCC1=O NQTADLQHYWFPDB-UHFFFAOYSA-N 0.000 description 2
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- WQDUMFSSJAZKTM-UHFFFAOYSA-N Sodium methoxide Chemical compound [Na+].[O-]C WQDUMFSSJAZKTM-UHFFFAOYSA-N 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 235000019253 formic acid Nutrition 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000004611 light stabiliser Substances 0.000 description 2
- 238000004811 liquid chromatography Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229940095102 methyl benzoate Drugs 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000012044 organic layer Substances 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000012312 sodium hydride Substances 0.000 description 2
- 229910000104 sodium hydride Inorganic materials 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- IOGXOCVLYRDXLW-UHFFFAOYSA-N tert-butyl nitrite Chemical compound CC(C)(C)ON=O IOGXOCVLYRDXLW-UHFFFAOYSA-N 0.000 description 2
- 239000012414 tert-butyl nitrite Substances 0.000 description 2
- NGNBDVOYPDDBFK-UHFFFAOYSA-N 2-[2,4-di(pentan-2-yl)phenoxy]acetyl chloride Chemical compound CCCC(C)C1=CC=C(OCC(Cl)=O)C(C(C)CCC)=C1 NGNBDVOYPDDBFK-UHFFFAOYSA-N 0.000 description 1
- VSWICNJIUPRZIK-UHFFFAOYSA-N 2-piperideine Chemical compound C1CNC=CC1 VSWICNJIUPRZIK-UHFFFAOYSA-N 0.000 description 1
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- 150000001263 acyl chlorides Chemical class 0.000 description 1
- 230000010933 acylation Effects 0.000 description 1
- 238000005917 acylation reaction Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- KCXMKQUNVWSEMD-UHFFFAOYSA-N benzyl chloride Chemical compound ClCC1=CC=CC=C1 KCXMKQUNVWSEMD-UHFFFAOYSA-N 0.000 description 1
- 229940073608 benzyl chloride Drugs 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 125000005594 diketone group Chemical group 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000012434 nucleophilic reagent Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/56—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds
- C07C45/562—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds with nitrogen as the only hetero atom
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/58—Preparation of carboxylic acid halides
- C07C51/60—Preparation of carboxylic acid halides by conversion of carboxylic acids or their anhydrides or esters, lactones, salts into halides with the same carboxylic acid part
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
- C07D295/02—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms containing only hydrogen and carbon atoms in addition to the ring hetero elements
- C07D295/027—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms containing only hydrogen and carbon atoms in addition to the ring hetero elements containing only one hetero ring
- C07D295/03—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms containing only hydrogen and carbon atoms in addition to the ring hetero elements containing only one hetero ring with the ring nitrogen atoms directly attached to acyclic carbon atoms
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the technical field of dibenzoyl methane processing, and discloses a method for synthesizing dibenzoyl methane, which comprises the following steps: step one, enamine preparation: reacting acetophenone and pyrrolidine under the catalysis of p-toluenesulfonic acid, and azeotropically dehydrating with toluene to obtain enamine; step two, preparing benzoyl chloride: benzoic acid reacts with thionyl chloride to generate benzoyl chloride; step three, preparing dibenzoyl methane: and (3) carrying out nucleophilic addition-elimination reaction and acidic hydrolysis on enamine and benzoyl chloride to obtain a target product. The invention 1 has mild reaction condition and less side reaction; the DBM prepared by the method has high overall yield and good product quality; in addition, the technical scheme generates less wastewater, generates no wastewater of high concentrated acid and solvent which are difficult to treat, generates no wastewater of high concentrated salt and solvent which are difficult to treat, and greatly reduces the difficulty of subsequent wastewater treatment.
Description
Technical Field
The invention relates to the technical field of dibenzoyl methane processing, in particular to a method for synthesizing dibenzoyl methane.
Background
Dibenzoylmethane DBM with the molecular formula C 15 H 12 O 2 It is a compound with diketone structure. Its most important use is as light stabilizer for thermoplastic plastics, widely used in PVC plastics and ABS resins. Because the dibenzoyl methane has the characteristics of no toxicity and no odor, the dibenzoyl methane conforms to the trend of environmental protection, and has an increasingly important position in the field of light stabilizers. With the continuous development of the functions of dibenzoylmethane, the demand for dibenzoylmethane at home and abroad is increasing continuously, and particularly, the demand for dibenzoylmethane with high content and good color is higher.
Although few methods for synthesizing dibenzoylmethane have been reported, few methods suitable for large-scale industrial production exist, and the problems of color difference, low content, high production cost and the like of products generally exist. In the prior art, the synthesis process of dibenzoylmethane mainly comprises the following steps: 1. acetophenone, benzyl chloride and sodium hydride are reacted in a solvent to obtain 1,3-diphenyl-acetone, then 1,3-diphenyl-acetone is oxidized under the catalysis of tert-butyl nitrite and N-hydroxysuccinimide to prepare a crude dibenzoyl methane product, and the crude dibenzoyl methane product is recrystallized by using methanol or ethanol as a recrystallization solvent to obtain a refined dibenzoyl methane product. 2. Benzoic acid and a large excess of methanol are used as raw materials, sulfuric acid is used as a catalyst to prepare methyl benzoate, the methyl benzoate generates DBM sodium salt under the catalytic action of sodium methoxide, and the DBM sodium salt is hydrolyzed by sulfuric acid to obtain dibenzoyl methane. The first method has the following problems: 1. the hydrogen is generated by using sodium hydride as a catalyst, the explosion limit of the hydrogen is 4-75.6%, and the method has great danger; 2. the catalysts, namely tert-butyl nitrite (1.1 equivalent) and N-hydroxysuccinimide (0.2 equivalent), are large in usage amount and have no recycling scheme, so that the raw material cost is high, and a large amount of waste liquid is not easy to treat. The second method has the following problems: 1. overall yield is not high and color is not good; 2. during the esterification reaction, the consumption of methanol is 4-10 times of the theoretical consumption, the consumption of sulfuric acid is also large, and a large amount of wastewater containing methanol and sulfuric acid is generated; 3. the carboxyl of the benzoic acid is directly connected with the benzene ring, the electrophilicity of the carboxyl is low due to the conjugation effect of the benzene ring, although the methanol is greatly excessive, the conversion rate of the benzoic acid is still not high, and the benzoic acid needs rectification and purification; 4. the condensation and hydrolysis steps generate a large amount of sodium sulfate, and the sodium sulfate contains a large amount of methanol, so that the wastewater treatment difficulty is high. Therefore, it is highly desirable to develop a method for synthesizing dibenzoylmethane with less side reactions, high overall yield, and less wastewater generation.
Disclosure of Invention
The invention aims to provide a method for synthesizing dibenzoyl methane, which solves the problems of more side reactions, low yield and difficult wastewater treatment in the production of dibenzoyl methane in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme: a method for synthesizing dibenzoyl methane comprises the following steps:
step one, enamine preparation: reacting acetophenone and pyrrolidine under the catalysis of p-toluenesulfonic acid, and azeotropically dehydrating with toluene to obtain enamine;
step two, preparation of benzoyl chloride: reacting benzoic acid with thionyl chloride to generate benzoyl chloride;
step three, preparing dibenzoyl methane: and carrying out nucleophilic addition-elimination reaction and acidic hydrolysis on enamine and benzoyl chloride to obtain a target product.
The principle and the advantages of the scheme are as follows: in practical application, the problems of higher magazine, lower yield and more three wastes always exist in the process of researching, developing and preparing the dibenzoyl methane. In the technical scheme, a brand-new dibenzoylmethane synthesis process is developed through careful research and development aiming at various problems in the dibenzoylmethane preparation process in the prior art. Firstly, acetophenone and secondary amine react to generate enamine, then enamine is used as a nucleophilic reagent to carry out nucleophilic addition-elimination reaction on acyl chloride to complete acylation, and finally the acylated enamine is subjected to acid hydrolysis by imine salt to obtain a target product DBM. The reaction mechanism of this reaction is shown below. In the process of project development, the selection of secondary amine is one of the difficulties of the technical scheme, and although more secondary amines have certain catalytic action, the defects of incomplete reaction and high cost exist. In addition, how to ensure the product yield and content of the DBM in the development process is another development difficulty of the technical scheme, and researches show that: the proportion of each raw material, the process moisture and the water content of the raw material have great influence on the yield and the purity of the DBM, and each index needs to be strictly controlled to ensure the yield and the quality of the dibenzoyl methane product.
The method comprises the following steps:
step two:
step three:
the beneficial effects of this technical scheme lie in:
1. the technical scheme has mild reaction conditions and fewer side reactions;
2. the DBM prepared by adopting the technical scheme has higher overall yield and better product quality;
3. the technical scheme generates less wastewater, does not generate wastewater of high concentrated acid and solvent which are difficult to treat, and also generates wastewater of high concentrated salt and solvent which are difficult to treat, thereby greatly reducing the difficulty of subsequent wastewater treatment;
4. the solvent of the technical scheme is easy to recycle and reuse, and can realize complete closed loop.
Preferably, as an improvement, in the first step, the molar ratio of the acetophenone to the tetrahydropyrrole is 1:2-1: 2.5.
in the technical scheme, the molar ratio of the acetophenone to the pyrrolidine has a great influence on the reaction process, the acetophenone cannot be completely reacted due to insufficient amount of the pyrrolidine, and the content of the final product is not high due to residual acetophenone. In addition, in the process of developing the technical scheme, the acetophenone is also tried to react with other secondary amines (morpholine and piperidine), but experiments prove that although morpholine and piperidine can also catalyze the reaction, the conversion rate of the raw material acetophenone is only about 70-80%. The residual acetophenone finally enters the finished product, so that the purity of the finished product is less than 90 percent.
Preferably, as an improvement, in the first step, the temperature of the catalytic reaction is 90-110 ℃, the reaction time is 4.5-7.5h, and the reflux is kept during the reaction.
In the technical scheme, the raw materials can not be reacted completely due to too low reaction temperature and too short reaction time. Increasing the reaction temperature and the reaction time leads to an increase in energy consumption. In the reaction process, proper reflux is always kept, toluene is used for taking out water and removing the water through a water separator, and the toluene can return to a reaction bottle for recycling. Research shows that when enamine is prepared, moisture generated by reaction needs to be removed, otherwise incomplete reaction is caused, and the final cost content is insufficient.
Preferably, as an improvement, in the first step, after the reaction is finished, water washing, atmospheric distillation and reduced pressure distillation are carried out.
In the technical scheme, after the reaction is finished, washing is carried out, and a lower-layer water phase is removed; and then distilling under normal pressure to remove excessive pyrrolidine, and distilling under reduced pressure to remove toluene, so that the purity of the product can be ensured, and the pyrrolidine and toluene can be recycled.
Preferably, as an improvement, in the second step, the molar ratio of the benzoic acid to the thionyl chloride is 1:2-1:3.
In the technical scheme, the molar ratio of the benzoic acid to the thionyl chloride has a great influence on the reaction process, too much benzoic acid can cause incomplete reaction of the benzoic acid, and residual benzoic acid enters a final product to influence the product content. The addition of excessive thionyl chloride has no effect on the reaction itself, but increases the cost. In addition, the thionyl chloride cannot contain water when preparing the acid chloride, which would otherwise lead to incomplete reaction and thus to an adverse effect on the product content.
Preferably, as an improvement, in the second step, the reaction temperature is 60-70 ℃, and the reaction time is 1-3 h.
In the technical scheme, the raw materials cannot be completely converted due to the excessively low reaction temperature, and the loss of thionyl chloride is increased due to the excessively high reaction temperature; the prolonged reaction time has no influence on the reaction, but the recovery rate of thionyl chloride is lowered and the energy consumption is increased.
Preferably, as a modification, in the second step, after the reaction is completed, atmospheric distillation and vacuum distillation are performed.
In the technical scheme, after the reaction is finished, excessive thionyl chloride is mainly removed through normal pressure distillation, and the solvent toluene is mainly removed through reduced pressure distillation, so that on one hand, the purity of the product can be ensured, and on the other hand, the recycling of the thionyl chloride and the toluene can be realized.
Preferably, as an improvement, in the step three, the molar ratio of the enamine to the benzoyl chloride is 1:1-1.
In the technical scheme, the molar ratio of enamine to benzoyl chloride has a great influence on the reaction process, enamine and benzoyl chloride can be completely converted in an equimolar ratio, and excessive addition of enamine or benzoyl chloride can result in residual benzoyl chloride or enamine. The residual benzoyl chloride or enamine is converted into benzoic acid or acetophenone by acidic hydrolysis, which affects the final product content.
Preferably, as an improvement, in the third step, the reaction temperature is 85-105 ℃, and the reaction time is 3-8h.
In the technical scheme, the reaction is incomplete due to too low reaction temperature or the reaction time needs to be prolonged, and the loss of reaction raw materials and a solvent is caused due to too high temperature; insufficient reaction time can lead to incomplete reaction, and prolonged reaction time can lead to waste of manpower and material resources.
Preferably, as an improvement, in the third step, the target product is obtained after the reaction is finished and the temperature is reduced, the acidolysis and the washing are carried out.
In the technical scheme, the purpose of acidolysis is to free the pyrrolidine, the purpose of water washing is to wash away residual acid, and the purity of the product can be improved through the acidolysis and water washing processes.
Drawings
FIG. 1 is a process flow diagram of example 1 of the present invention.
FIG. 2 is a dibenzoylmethane liquid chromatogram of example 1 of the present invention.
Detailed Description
The following is a detailed description of the embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents and the like used are all commercially available.
Example 1
As shown in fig. 1, a method for synthesizing dibenzoylmethane comprises the following steps:
step one, enamine preparation: a clean dry 500ml reaction flask was charged with 120.15g (1 mol) acetophenone, 142.24g (2 mol) tetrahydropyrrole, 4.9g (0.05 mol) sulfuric acid, and 100g toluene. The temperature is raised to 90-110 ℃ for 5 hours. Proper reflux is kept all the time in the reaction process, water is removed by taking the water out of the water separator by utilizing toluene, and the toluene returns to the reaction bottle. After the reaction, 100g of tap water was added, stirred for 5min, and left to stand for 5min, and the lower aqueous phase was separated. The excess tetrahydropyrrole is slowly distilled off at normal pressure (75-90 ℃) and then the toluene is distilled off under reduced pressure (70-100 ℃). After the evaporation is finished, the temperature is reduced to the room temperature, 169g of white liquid enamine is obtained, and the yield is 97.54%.
Step two, preparing benzoyl chloride: 200g of toluene was added to a clean and dry 500ml reaction flask, 61.06g (0.5 mol) of solid formic acid was added under stirring, and 119g (1 mol) of thionyl chloride was added dropwise after the temperature in the reaction vessel was raised to 50 to 60 ℃. The temperature in the reaction bottle is kept between 60 and 70 ℃ in the dropping process, and the gas generated by the reaction is absorbed by water and is dropped after about 2 hours. After the dripping is finished, the reaction is kept for 1h. After the reaction is finished, excess thionyl chloride (65-85 ℃) is slowly evaporated out under normal pressure, and then the solvent toluene is evaporated out under reduced pressure (70-100 ℃). After the evaporation is finished, the temperature is reduced to room temperature to obtain 70g of white viscous liquid benzoyl chloride, and the yield is 99.59%.
Step three, DBM preparation: a clean and dry 500ml reaction flask was charged with 140.57g (1 mol) of benzoyl chloride from step two and 173.26g (1 mol) of enamine from step one. Then heating to 95 ℃ and keeping the temperature for reaction for 5 hours. After the reaction is finished, the temperature is reduced to 50 ℃, and 120g of 30% hydrochloric acid aqueous solution is added for acidolysis for 30min. After the acidolysis is finished, removing a water layer. The organic layer was washed with 100g of 5% sodium carbonate solution and 100g of tap water, respectively, to obtain 222.3g of white viscous liquid DBM with a yield of 99.13%.
Example 2 (2 times the amount of the raw material added in example 2)
A method for synthesizing dibenzoylmethane comprises the following steps:
step one, enamine preparation: a clean and dry 1000ml reaction flask was charged with 240.3g (2 mol) of acetophenone, 5363 g (4 mol) of tetrahydropyrrole 284.48g, 9.8g (0.1 mol) of sulfuric acid, and 200g of toluene. The temperature is raised to 90-110 ℃ for 5 hours. Proper reflux is kept all the time in the reaction process, toluene is used for taking out water and removing the water through a water separator, and the toluene returns to the reaction bottle. After the reaction, 100g of tap water was added, stirred for 5min, and left to stand for 5min, and the lower aqueous phase was removed. The excess tetrahydropyrrole is slowly distilled off at normal pressure (75-90 ℃) and then the toluene is distilled off under reduced pressure (70-100 ℃). After the evaporation is finished, the temperature is reduced to room temperature, and 339.5g of white liquid enamine is obtained, and the yield is 97.23%.
Step two, preparation of benzoyl chloride: 400g of toluene is added into a clean and dry 1000ml reaction bottle, 122.12g (1 mol) of solid formic acid is added while stirring, and 238g (2 mol) of thionyl chloride is added dropwise after the temperature in the reaction kettle is raised to 50-60 ℃. The temperature in the reaction bottle is kept between 60 and 70 ℃ in the dropping process, and the gas generated by the reaction is absorbed by water and is dropped after about 2 hours. After the dripping is finished, the reaction is kept for 1h. After the reaction is finished, excess thionyl chloride (65-85 ℃) is slowly evaporated out under normal pressure, and then the solvent toluene is evaporated out under reduced pressure (70-100 ℃). After the evaporation is finished, cooling to room temperature to obtain 139.5g of white viscous liquid benzoyl chloride, wherein the yield is 99.18%.
Step three, DBM preparation: a clean dry 1000ml reaction flask was charged with 281.14g (2 mol) of the benzoyl chloride from step two and 8978 g (2 mol) of the enamine from step one, 346.52. Then heating to 95 ℃ and keeping the temperature for reaction for 5 hours. After the reaction is finished, the temperature is reduced to 50 ℃, 240g of 30% hydrochloric acid aqueous solution is added for acidolysis for 30min. After the acidolysis is finished, removing a water layer. The organic layer was washed with 100g of 5% sodium carbonate solution and 100g of tap water, respectively, to obtain 100.5 g of white viscous liquid DBMS with a yield of 98.83%.
Examples 1 to 3 are examples of the present invention, comparative examples 1 to 10 are comparative examples of the present invention, and each example and comparative example are different only in selection of a part of raw materials and parameters, and are described in table 1. Wherein, the column of maintaining reflux refers to whether proper reflux is maintained in the reaction process of the acetophenone and the secondary amine.
TABLE 1
Experiment one: DBM product characterization
The DBM product prepared in example 1 was characterized by a liquid chromatography method, and the chromatogram is shown in fig. 2. The result shows that the purity and the content of the dibenzoyl methane obtained by the invention can reach higher level.
Experiment two: DBM yield and content (purity)
The yield and content of the DBM prepared in each example and the comparative example are measured, wherein the content measurement method is liquid chromatography, each group is subjected to three repeated experiments, and the specific results are detailed in table 2.
TABLE 2
| DBM yield (%) | DBM content (%) | |
| Example 1 | 99.13 | 98.97 |
| Example 2 | 98.83 | 98.68 |
| Example 3 | 98.91 | 98.77 |
| Comparative example 1 | 67.54 | 78.49 |
| Comparative example 2 | 71.45 | 69.44 |
| Comparative example 3 | 49.25 | 51.23 |
| Comparative example 4 | 32.18 | 35.41 |
| Comparative example 5 | 92.58 | 91.67 |
| Comparative example 6 | 85.68 | 87.59 |
| Comparative example 7 | 52.35 | 49.54 |
| Comparative example 8 | 34.21 | 37.59 |
| Comparative example 9 | 32.47 | 29.42 |
| Comparative example 10 | 31.52 | 31.2 |
The experimental result of the comparative example 1 shows that morpholine is used for replacing pyrrolidine, the yield and the content of the product are both obviously reduced, and the reaction activity of morpholine is obviously lower than that of pyrrolidine; the experimental result of the comparative example 2 shows that replacing pyrrolidine with piperidine results in significantly reduced yield and content of the product, which indicates that the reaction activity of piperidine is significantly lower than that of pyrrolidine; the experimental results of comparative example 3 and comparative example 4 show that the yield and the content of the product are reduced sharply by reducing the amount of the pyrrolidine, which indicates that a large amount of acetophenone cannot be converted into enamine and further cannot be converted into the product due to insufficient amount of the pyrrolidine; comparative example 5 the experimental results show that maintaining a certain reflux will allow the reaction to proceed more thoroughly; the experimental results of comparative example 6 and comparative example 7 show that the yield and the content of the product are reduced to some extent by reducing the amount of thionyl chloride, which indicates that insufficient amount of thionyl chloride causes benzoic acid not to be completely converted into benzoyl chloride and further not to be converted into the product; the experimental result of comparative example 8 shows that the content of water in thionyl chloride causes a great decrease in the yield and content of the product because benzoic acid cannot be converted into benzoyl chloride and further into the product due to the reaction of thionyl chloride with water; the experimental results of comparative example 9 show that insufficient amount of enamine leads to significant decrease in product yield and content because insufficient amount of enamine leads to incomplete reaction of benzoyl chloride; the experimental result of comparative example 9 shows that insufficient amount of benzoyl chloride results in significant decrease of product yield and content because insufficient amount of benzamide results in incomplete reaction of enamine;
the following conclusions can be drawn from the above comparative experiments: (1) the reaction activity of the pyrrolidine is higher than that of morpholine and piperidine. (2) The amount of tetrahydropyridine used was 2 times or more that of acetophenone. (3) Maintaining reflux can increase the yield and content of the product. (4) The amount of thionyl chloride used was 2 times or more as much as benzoic acid. (5) The water content of thionyl chloride can seriously affect the yield and the content of the product. (5) The yield and content of the product are influenced by the high or low ratio of the enamine to the benzoyl chloride.
The foregoing is merely an example of the present invention and common general knowledge in the art of designing and/or characterizing particular aspects and/or features is not described in any greater detail herein. It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several variations and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be defined by the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.
Claims (10)
1. The method for synthesizing dibenzoylmethane is characterized by comprising the following steps of:
step one, enamine preparation: reacting acetophenone and pyrrolidine under the catalysis of p-toluenesulfonic acid, and azeotropically dehydrating with toluene to obtain enamine;
step two, preparation of benzoyl chloride: benzoic acid reacts with thionyl chloride to generate benzoyl chloride;
step three, preparing dibenzoyl methane: and (3) carrying out nucleophilic addition-elimination reaction and acidic hydrolysis on enamine and benzoyl chloride to obtain a target product.
2. The method for synthesizing dibenzoylmethane as claimed in claim 1, wherein: in the first step, the molar ratio of the acetophenone to the pyrrolidine is 1:2-1.
3. The method for synthesizing dibenzoylmethane as claimed in claim 2, wherein: in the first step, the temperature of the catalytic reaction is 90-110 ℃, the reaction time is 4.5-7.5h, and the reflux is kept in the reaction process.
4. A method of synthesizing dibenzoylmethane as claimed in claim 3, wherein: in the first step, after the reaction is finished, water washing, normal pressure distillation and reduced pressure distillation are carried out.
5. The method for synthesizing dibenzoylmethane as claimed in claim 4, wherein: in the second step, the molar ratio of the benzoic acid to the thionyl chloride is 1:2-1:3.
6. The method of claim 5, wherein the dibenzoylmethane is synthesized by: in the second step, the reaction temperature is 60-70 ℃, and the reaction time is 1-3 h.
7. The method for synthesizing dibenzoylmethane of claim 6, wherein: and in the second step, after the reaction is finished, normal pressure distillation and reduced pressure distillation are carried out.
8. The method of claim 7, wherein the dibenzoylmethane is synthesized by: in the third step, the mol ratio of enamine to benzoyl chloride is 1:1-1.
9. The method of claim 8, wherein the dibenzoylmethane is synthesized by: in the third step, the reaction temperature is 85-105 ℃, and the reaction time is 3-8h.
10. The method of claim 9, wherein the dibenzoylmethane is synthesized by: and in the third step, after the reaction is finished, cooling, carrying out acidolysis and washing to obtain a target product.
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| CN110818543A (en) * | 2018-08-09 | 2020-02-21 | 山东瑞丰高分子材料股份有限公司燕崖分公司 | Novel method for efficiently synthesizing dibenzoyl methane |
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| CN110818543A (en) * | 2018-08-09 | 2020-02-21 | 山东瑞丰高分子材料股份有限公司燕崖分公司 | Novel method for efficiently synthesizing dibenzoyl methane |
Non-Patent Citations (2)
| Title |
|---|
| AI-E WANG 等: "Enamines as Surrogates of Alkene Carbanions for the Reductive Alkenylation of Secondary Amides: An Approach to Allylamines" * |
| 梁波 等: "2,5-二芳基-1,3,4-噁二唑铕配合物的合成和发光性能研究" * |
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