CN112341408B - Preparation method of coconut aldehyde - Google Patents
Preparation method of coconut aldehyde Download PDFInfo
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- CN112341408B CN112341408B CN202011328212.4A CN202011328212A CN112341408B CN 112341408 B CN112341408 B CN 112341408B CN 202011328212 A CN202011328212 A CN 202011328212A CN 112341408 B CN112341408 B CN 112341408B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/26—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
- C07D307/30—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D307/32—Oxygen atoms
- C07D307/33—Oxygen atoms in position 2, the oxygen atom being in its keto or unsubstituted enol form
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- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
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Abstract
The invention discloses a preparation method of coconut aldehyde, which comprises the following steps: step one, mixing and uniformly stirring n-hexanol, acrylic acid and di-tert-butyl peroxide, and keeping the temperature of the obtained mixed solution; step two, mixing n-hexanol and a beta molecular sieve catalyst, stirring and heating and preserving heat under a nitrogen environment, dropwise adding the mixed liquid obtained in the step one at a constant speed under the condition of heat preservation, continuously separating by-product water, tert-butanol and methanol in the reaction process, and continuously reacting for 1 to 2h after dropwise adding; and step three, after the reaction is finished, cooling, recovering low-boiling-point substances and n-hexanol in the reaction liquid in vacuum, after the recovery is finished, cooling to obtain a crude product, and performing reduced pressure rectification on the crude product to obtain a cocoaldehyde product. The novel environment-friendly efficient beta molecular sieve catalyst adopted by the invention shows good catalytic activity and selectivity in the synthesis of the coconut aldehyde, can be repeatedly utilized, can be recycled through modes such as high-temperature roasting and the like, has high reaction yield, is easy to control the process, and is beneficial to forming industrial mass production.
Description
Technical Field
The invention belongs to the technical field of fine chemical engineering, relates to synthesis of spices, and particularly relates to a preparation method of coconut aldehyde.
Background
Coconut aldehyde, also known as gamma-nonalactone, is colorless to light yellow transparent liquid, has coconut aroma, has fruity aroma similar to peach, apricot and plum after being diluted, and is naturally present in peach and apricot. Density 0.961-0.966 g/mL, boiling point 266 deg.C (760 mmHg), refractive index 1.4450-1.4500, and acid value less than 0.2. One of the most commonly used lactone flavors is GRAS (generally recognized as safe) by FEMA (american association of flavors and extracts manufacturers), FEMA number 2781, and approved for consumption by FDA (american food and drug administration), european council lists cocoaldehyde in a list of artificial flavors that can be used in food products without jeopardizing human health. The cocoanut aldehyde can be used in daily essence formula for preparing flower essence such as fructus Gardeniae, lignum Aquilariae Resinatum, and flos Jasmini sambac with oriental essence in an amount of 2%, or edible essence formula for preparing fruit essence such as coconut, peach, apricot, and cherry.
At present, the related technologies at home and abroad of the product mainly comprise the following three types:
1. direct synthesis by intramolecular reaction
Hydroxy acids, hydroxy esters and hydroxy acid derivatives can be converted directly into lactones by means of intramolecular reactions. As the catalyst, inorganic acids (e.g., hydrochloric acid, sulfuric acid, etc.), organic acids (e.g., p-xylene sulfonic acid, p-toluene sulfonyl chloride, 2,4,6-trimethylbenzene sulfonyl chloride, etc.) and the like are generally used. For example, optically pure gamma-hydroxydecanoic acid undergoes intramolecular cyclization under acid catalysis to form 4-hexyl-gamma-butyrolactone.
2. Isomerization and lactonization of unsaturated acids
The beta-unsaturated decenoic acid is prepared by isomerizing omega-decenoic acid in sulfuric acid to form beta-unsaturated decenoic acid and heating in the presence of an acid catalyst such as sulfuric acid. The gamma undecalactones are prepared industrially by isomerization of omega-undecylenic acid in sulfuric acid and subsequent esterification. The catalyst can also be mixed acid composed of perchloric acid and concentrated sulfuric acid, and Liu Wei adopts mixed acid composed of perchloric acid and concentrated sulfuric acid as catalyst, so that the above-mentioned reaction condition is improved, and the reaction time of using concentrated sulfuric acid as catalyst is shortened. Japanese patent discloses that decenoic acid undergoes cyclization in the presence of polyphosphoric acid, an acidic ion exchange resin, solid phosphoric acid and other acidic catalysts to prepare gamma-decalactone.
The method has short synthetic route and simple reaction conditions, but the raw material omega-decenoic acid is difficult to obtain and is not easy to industrialize.
3. Synthesis of gamma-lactone by radical addition of alcohol and unsaturated acid (reaction of alcohol with acrylic acid or ester)
In the search for inexpensive and readily available raw materials, gamma-butyrolactone is prepared by the free radical addition reaction of a primary alcohol and an acrylate in the presence of a free radical initiator. There are many Japanese patent documents on such reactions, which are carried out by forming a radical from an alcohol in the presence of a radical initiator and then adding an unsaturated carboxylic acid ester.
The Japanese Beacon company patent discloses a method for preparing gamma-decalactone. Boric acid, phosphoric acid, p-toluenesulfonic acid and the like are added in addition to di-t-butyl peroxide. The gamma-decalactone is obtained by about 80 percent. The method takes cheap and easily-obtained chemical raw material acrylic acid or methyl acrylate as raw material to synthesize the gamma-butyrolactone, has easily-obtained raw material, high product yield, mild process conditions and lower cost, and is an ideal industrial production method.
In actual industrial production, the catalyst for synthesizing the cocoaldehyde is a traditional Lewis acid catalyst such as inorganic acid (such as zinc chloride, hydrochloric acid, sulfuric acid and the like) and organic acid (such as xylene sulfonic acid, paratoluensulfonyl chloride, 2,4,6-trimethylbenzene sulfonyl chloride and the like). The used catalyst has the problems of large catalyst dosage, difficult separation from products, incapability of being reused and the like.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a preparation method of coconut aldehyde, the novel environment-friendly efficient beta molecular sieve catalyst adopted by the invention shows good catalytic activity and selectivity in synthesis of coconut aldehyde, can be recycled through high-temperature roasting and other modes, has high reaction yield, is easy to control the process, and is beneficial to formation of industrial mass production.
The invention is realized by the following technical scheme:
a preparation method of coconut aldehyde comprises the following steps:
step one, mixing and uniformly stirring n-hexanol, acrylic acid and di-tert-butyl peroxide, and keeping the temperature of the obtained mixed solution;
step two, mixing n-hexanol and a beta molecular sieve catalyst, stirring and heating and preserving heat under a nitrogen environment, dropwise adding the mixed liquid obtained in the step one at a constant speed under the condition of heat preservation, continuously separating by-product water, tert-butanol and methanol in the reaction process, and continuously reacting for 1 to 2h after dropwise adding;
and step three, after the reaction is finished, cooling, recovering low-boiling-point substances and n-hexanol in the reaction liquid in vacuum, after the recovery is finished, cooling to obtain a crude product, and performing reduced pressure rectification on the crude product to obtain a cocoaldehyde product.
The invention further improves the scheme as follows:
in the first step, the mass ratio of n-hexanol to acrylic acid to di-tert-butyl peroxide is 80 to 640.
Further, in the second step, the mass ratio of the n-hexanol to the beta molecular sieve catalyst is 960-1280, 1-25, and the temperature for heat preservation is 140-180 ℃.
Further, in the second step, the dripping time is 6 to 12h, and the speed is 40 +/-5 g/h.
Further, the mass ratio of the acrylic acid to the beta molecular sieve catalyst is 18 to 22.
Further, the beta molecular sieve catalyst is H-beta molecular sieve catalyst, wherein the molar ratio of silicon to aluminum is SiO 2 /Al 2 O 3 ＝30～60。
Compared with the prior art, the invention has the beneficial effects that:
beta molecular sieve catalyst (Si/Al molar ratio SiO) used in the invention 2 /Al 2 O 3 H-beta molecular sieve catalyst of = 30-60) shows good catalytic activity, selectivity and stability in coconut aldehyde synthesis, can be recycled by high-temperature roasting and other modes, has high reaction yield and easily controlled process, and is beneficial to industrial mass production.
Detailed Description
Example 1
Uniformly mixing 232.0g (2.27 mol) of n-hexanol, 160.0g (2.22 mol) of acrylic acid and 25.6g (0.18 mol) of di-tert-butyl peroxide according to the feeding proportion, transferring the mixture into a high-level tank, and preserving heat at the temperature of 10-20 ℃ for later use; 1048.0g (10.27 mol) of n-hexanol, 8.0g of SiO 2 /Al 2 O 3 Adding 30H-beta molecular sieve catalyst into a 2000mL glass reaction kettle, after nitrogen is filled for replacement, starting a stirrer and a high-temperature circulating heater, heating to 140-160 ℃, and preserving heat; beginning to drip the mixture in the head tank, wherein the dripping speed is controlled to be 40 +/-5 g/h, and the dripping time is 6-12h; continuously separating by-products of water, tert-butyl alcohol and methanol from the top of the tower in the reaction process, and after dropwise adding, preserving heat for 1 to 2h to finish the reaction. Cooling to 120 + -5 deg.C, circulating with boiled water, vacuum at 50 + -5 mmHg, adjusting reflux ratio to 3:3, collecting low-boiling-point substances, recovering n-hexanol when the top temperature is not less than 60 deg.C, and recovering n-hexanol when the kettle temperature is more than 150 deg.CAfter the temperature is reduced to 40-50 ℃, transferring the crude product to a vacuum distillation kettle for distillation and collection to obtain 298.8g of cocoaldehyde with the GC content of 99.6 percent, wherein the product yield is 86.2 percent. And filtering the rectifying still liquid, and collecting the H-beta molecular sieve catalyst for recycling.
Example 2
Uniformly mixing 60.0g of n-hexanol, 160.0g of acrylic acid and 50g of di-tert-butyl peroxide according to the feeding proportion, transferring the mixture into a high-level tank, and keeping the temperature at 10-20 ℃ for later use; adding 1280g of n-hexanol and 8g of the H-beta molecular sieve catalyst recovered in the example 1 into a 2000mL glass reaction kettle, after nitrogen gas is filled for replacement, starting a stirrer and a high-temperature circulating heater, heating to 140-160 ℃, and preserving heat; beginning to drip the mixture in the head tank, wherein the dripping speed is controlled to be 40 +/-5 g/h, and the dripping time is 6-12h; continuously separating by-products of water, tert-butyl alcohol and methanol from the top of the tower in the reaction process, and after dropwise adding, preserving heat for 1 to 2h to finish the reaction. Cooling to 120 +/-5 ℃, circulating with boiled water, performing vacuum of 50 +/-5 mmHg, adjusting reflux ratio to 3:3, collecting low-boiling-point substances, beginning to recover n-hexanol when the top temperature is more than or equal to 60 ℃, ending the recovery of n-hexanol when the kettle temperature is more than 150 ℃, cooling to 40-50 ℃, transferring the crude product to a reduced pressure rectifying kettle, rectifying and collecting to obtain 291.5g of cocoaldehyde with the GC content of 99.4%, wherein the product yield is 84.1%. And filtering the rectifying still liquid, and collecting the H-beta molecular sieve catalyst for recycling.
Example 3
Uniformly mixing 640.0g of n-hexanol, 160.0g of acrylic acid and 10g of di-tert-butyl peroxide according to a feeding proportion, transferring the mixture into a high-level tank, and keeping the temperature at 10-20 ℃ for later use; adding 960g of n-hexanol and 8g of the H-beta molecular sieve catalyst recovered in the example 2 into a 2000mL glass reaction kettle, after nitrogen gas is filled for replacement, starting a stirrer and a high-temperature circulating heater, heating to 140-160 ℃, and preserving heat; beginning to drip the mixture in the head tank, wherein the dripping speed is controlled to be 40 +/-5 g/h, and the dripping time is 6-12h; and continuously separating by-products of water, tert-butanol and methanol from the top of the tower in the reaction process, and preserving heat for 1 to 2h after the dropwise addition is finished, thus finishing the reaction. Cooling to 120 +/-5 ℃, performing a boiled water ring pump, performing vacuum of 50 +/-5 mmHg, adjusting the reflux ratio of 3:3, collecting low-boiling-point substances, beginning to recover n-hexanol when the top temperature is more than or equal to 60 ℃, ending the recovery of n-hexanol when the kettle temperature is more than 150 ℃, cooling to 40-50 ℃, transferring the crude product to a reduced pressure rectification kettle, rectifying and collecting 285.7g of cocoaldehyde with the GC content of 99.5%, wherein the product yield is 82.4%. And filtering the rectifying still liquid, and collecting the H-beta molecular sieve catalyst for recycling.
Example 4
The catalyst recovered in example 3 was calcined at 800 ℃ and used as the catalyst in this example, the other operations were the same as in example 1, and in this example, 290.2g of cocoaldehyde with a GC content of 99.3% was collected, and the product yield was 83.7%.
Example 5
Uniformly mixing 232.0g (2.27 mol) of n-hexanol, 160.0g (2.22 mol) of acrylic acid and 25.6g (0.18 mol) of di-tert-butyl peroxide according to the feeding proportion, transferring the mixture into a high-level tank, and preserving heat at the temperature of 10-20 ℃ for later use; 1048.0g (10.27 mol) n-hexanol, 4.0g SiO 2 /Al 2 O 3 Adding 60H-beta molecular sieve catalyst into a 2000mL glass reaction kettle, after nitrogen gas is filled for replacement, starting a stirrer and a high-temperature circulating heater, heating to 140-160 ℃, and preserving heat; beginning to drip the mixture in the head tank, wherein the dripping speed is controlled to be 40 +/-5 g/h, and the dripping time is 6-12h; and continuously separating by-products of water, tert-butanol and methanol from the top of the tower in the reaction process, and preserving heat for 1 to 2h after the dropwise addition is finished, thus finishing the reaction. Cooling to 120 +/-5 ℃, circulating with boiled water, performing vacuum of 50 +/-5 mmHg, adjusting reflux ratio to 3:3, collecting low-boiling-point substances, beginning to recover n-hexanol when the top temperature is more than or equal to 60 ℃, ending the recovery of n-hexanol when the kettle temperature is more than 150 ℃, cooling to 40-50 ℃, transferring the crude product to a reduced pressure rectification kettle, rectifying and collecting to obtain 272.1g of cocoaldehyde with GC content of 99.6%, wherein the product yield is 78.5%.
Example 6
Uniformly mixing 304.0g (2.98 mol) of n-hexanol, 160.0g (2.22 mol) of acrylic acid and 25.6g (0.18 mol) of di-tert-butyl peroxide according to the feeding proportion, transferring the mixture into a high-level tank, and preserving heat at the temperature of 10-20 ℃ for later use; 976.0g (9.57 mol) of n-hexanol, 8.0g of SiO 2 /Al 2 O 3 Adding 50H-beta molecular sieve catalyst into a 2000mL glass reaction kettle, after nitrogen is filled for replacement, starting a stirrer and a high-temperature circulating heater, heating to 140-160 ℃, and preserving heat; the mixture in the head tank is dripped into the head tank,the dripping speed is controlled to be 40 +/-5 g/h, and the dripping time is 6-12h; and continuously separating by-products of water, tert-butanol and methanol from the top of the tower in the reaction process, and preserving heat for 1 to 2h after the dropwise addition is finished, thus finishing the reaction. Cooling to 120 +/-5 ℃, performing a boiled water ring pump, performing vacuum of 50 +/-5 mmHg, adjusting the reflux ratio to 3:3, collecting low-boiling-point substances, beginning to recover hexanol when the top temperature is more than or equal to 60 ℃, ending the recovery of hexanol when the kettle temperature is more than 150 ℃, cooling to 40-50 ℃, transferring the crude product to a reduced pressure rectification kettle, and performing rectification and collection to obtain 295.7g of cocoaldehyde with 99.6 percent of GC content, wherein the product yield is 85.3 percent.
Claims (5)
1. A preparation method of coconut aldehyde is characterized by comprising the following steps:
step one, mixing and uniformly stirring n-hexanol, acrylic acid and di-tert-butyl peroxide, and keeping the temperature of the obtained mixed solution;
step two, mixing n-hexanol and a beta molecular sieve catalyst, stirring and heating and preserving heat under a nitrogen environment, dropwise adding the mixed liquid obtained in the step one at a constant speed under the condition of heat preservation, continuously separating by-product water, tert-butanol and methanol in the reaction process, and continuously reacting for 1 to 2h after dropwise adding;
after the reaction is finished, cooling, recovering low-boiling-point substances and n-hexanol in the reaction liquid in vacuum, after the recovery is finished, cooling to obtain a crude product, and performing reduced pressure rectification on the crude product to obtain a cocoaldehyde product;
the beta molecular sieve catalyst is H-beta molecular sieve catalyst, wherein the molar ratio of silicon to aluminum is SiO 2 /Al 2 O 3 ＝30～60。
2. The method for preparing coconut aldehyde according to claim 1, wherein the method comprises the following steps: in the first step, the mass ratio of n-hexanol to acrylic acid to di-tert-butyl peroxide is 80 to 640.
3. The method for preparing coconut aldehyde according to claim 1, wherein the method comprises the following steps: in the second step, the mass ratio of the n-hexanol to the beta molecular sieve catalyst is 960-1280, 1-25, and the temperature for heat preservation is 140-180 ℃.
4. The method for preparing coconut aldehyde according to claim 1, wherein the method comprises the following steps: in the second step, the dripping time is 6 to 12h, and the speed is 40 +/-5 g/h.
5. The method for preparing coconut aldehyde according to claim 1, wherein the method comprises the following steps: the mass ratio of the acrylic acid to the beta molecular sieve catalyst is 18 to 22.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04275282A (en) * | 1991-03-01 | 1992-09-30 | T Hasegawa Co Ltd | Production of gamma-lactone |
| CN102060816A (en) * | 2010-12-31 | 2011-05-18 | 麦仑（厦门）生物科技有限公司 | Synthesis method of gamma-nonalactone |
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2020
- 2020-11-24 CN CN202011328212.4A patent/CN112341408B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04275282A (en) * | 1991-03-01 | 1992-09-30 | T Hasegawa Co Ltd | Production of gamma-lactone |
| CN102060816A (en) * | 2010-12-31 | 2011-05-18 | 麦仑（厦门）生物科技有限公司 | Synthesis method of gamma-nonalactone |
Non-Patent Citations (4)
| Title |
|---|
| SYNTHESIS OF γ-NONALACTONE AND γ-UNDECALACTONE;Nikishin,G.I.等;《 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya》;19621231;第1786-1787页 * |
| γ-内酯的合成;宣慧;《南京理工大学硕士学位论文》;20061231;第10页 * |
| γ-烷基-γ-丁内酯的制备和应用;李宏;《香料香精化妆品》;20010430(第2期);第23-24页 第2.7节，第22页右栏 * |
| 分子筛环化合成椰子醛;黄自明;《化学世界》;19861231;第396-398页 * |
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