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CN-122010886-A - Method for synthesizing nerol by 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylprop-1-en-1-yl) oxy-cyclohexane

CN122010886ACN 122010886 ACN122010886 ACN 122010886ACN-122010886-A

Abstract

The invention belongs to the technical field of organic synthesis, and particularly discloses a method for synthesizing nerol by 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy-cyclohexane, which comprises the following steps of uniformly mixing 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy-cyclohexane with a solvent, preheating, pumping the mixture into a fixed bed reactor filled with a SO 4 2‑ -Fe 2 O 3 -La 2 O 3 /SBA-15 solid acid catalyst at a certain flow rate for reaction, reacting for a period of time at a certain temperature and pressure, cooling the reaction product by a condenser to obtain a crude product, and rectifying the crude product to obtain a nerol product and an isopentenol byproduct; the synthesis method has the advantages of mild reaction conditions, high reaction speed and high production efficiency, and no wastewater is generated in the post-reaction treatment, and the solvent and the catalyst can be reused in the next batch after being recovered, SO that the production cost is greatly reduced, and the industrial production is easy to realize. Meanwhile, the utilization of byproducts is realized, and the production cost of the nerol is reduced.

Inventors

  • DING YALAN
  • LIU HAIBING
  • TAO ZEKUN
  • ZHANG JINGUI
  • YAN LEI

Assignees

  • 江苏宏邦化工科技有限公司

Dates

Publication Date
20260512
Application Date
20251218

Claims (9)

  1. 1. A process for synthesizing nerol from 4-methyl-4- [ (3-methylbutan-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy-cyclohexane includes such steps as mixing 4-methyl-4- [ (3-methylbutan-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy-cyclohexane with solvent, preheating, loading in fixed-bed reactor containing SO 4 2- -Fe 2 O 3 -La 2 O 3 /SBA-15 solid acid catalyst, reacting at a certain flow rate, cooling by condenser, rectifying to obtain nerol product and isopentenol by-product; The mole ratio of La to Fe in the SO 4 2- -Fe 2 O 3 -La 2 O 3 /SBA-15 solid acid catalyst is 1:8-10, the total load of Fe 2 O 3 and La 2 O 3 is 1.5-4%, and the mole ratio of sulfate radical on the surface of the solid acid catalyst to ferric oxide is 1.5-1.8.
  2. 2. A process for the synthesis of nerol ether from 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxa-ne according to claim 1, wherein the solvent used is one or more of toluene, cyclohexane, N-hexane, N-heptane, ethyl acetate, acetonitrile, tetrahydrofuran, ethylene glycol dimethyl ether, 1, 4-dioxane, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone or water.
  3. 3. A method for synthesizing nerol ether by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylprop-1-en-1-yl) oxetan according to claim 1 or 2, wherein the solvent is used in an amount of 0.2-3 times the mass of the raw materials.
  4. 4. The method for synthesizing nerol ether by 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy cyclohexane according to claim 1, wherein the preheating temperature is 60 ℃ to 120 ℃, the reaction temperature is 120 ℃ to 240 ℃, and the condenser temperature is 30 ℃ to 80 ℃.
  5. 5. The method for synthesizing nerol ether by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan according to claim 1, wherein the reaction pressure is 101Kpa to 550Kpa.
  6. 6. The method for synthesizing nerol ether by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan according to claim 1, wherein the feeding flow rate is 10-80 mL/min, and the residence time of the materials in the reactor is 10s-200s.
  7. 7. The method for synthesizing nerol ether by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan according to claim 1, wherein the diameter of the fixed bed reactor is 25mm, the filling height of the catalyst is 400-800 mm, and the filling amount is 50-100 g.
  8. 8. A process for synthesizing nerol ether from 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy cyclohexane according to claim 1, wherein the solid acid catalyst SO 4 2- -Fe 2 O 3 -La 2 O 3 /SBA-15 is prepared by immersing SBA-15 in a mixed aqueous solution of lanthanum nitrate and ferric nitrate in equal volume, standing, transferring into a hydrothermal reaction kettle containing ethanol for hydrothermal reaction, drying, treating at high temperature for the first time, heating and stirring in (NH 4 ) 2 SO 4 ) aqueous solution, filtering, drying, and treating at high temperature for the second time to obtain solid acid catalyst SO 4 2- -Fe 2 O 3 -La 2 O 3 /SBA-15.
  9. 9. The method for synthesizing nerol ether by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan according to claim 8, wherein the hydrothermal reaction is carried out at a temperature of 100-150 ℃ for 3-5 hours; and/or the drying temperature is 100-120 ℃ and the drying time is 10-14 h; And/or the first high temperature treatment process is that the temperature is raised to 500 ℃ in a muffle furnace at 2.5 ℃ per min and kept at 5h ℃; And/or heating and stirring for 4-8 hours at the temperature of 70-90 ℃; And/or the second high-temperature treatment is carried out by heating to 550 ℃ in a muffle furnace at 5 ℃ per min and preserving heat at 4h.

Description

Method for synthesizing nerol by 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylprop-1-en-1-yl) oxy-cyclohexane Technical Field The invention belongs to the technical field of organic synthesis, relates to synthesis of a perfume compound nerol, and in particular relates to a method for synthesizing the nerol by using 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylprop-1-en-1-yl) oxetane. Background 3, 6-Dihydro-4-methyl-2- (2-methyl-1-propenyl) -2H-pyran, commonly known as neroli ether, has strong floral fragrance, orange flower oil-like fragrance and fresh youth smell, is commonly used for floral fragrance types such as orange flowers, jasmine, honeysuckle, hyacinth and the like, can also be used for refreshing citrus/bluish green, provides bright feel in the top fragrance, has natural body fragrance transition, and is harmonious with musk and woody fragrance. Meanwhile, the sweet agent is also used for the flavors of citrus and tropical fruits, and can obviously improve the flavor defect of artificial sweeteners and improve the palatability in low-sugar/sugar-free beverages and candies. In addition, the hydrogenation product of the dihydrorose ether has strong floral fragrance, is a fragrance construction raw material with relatively stable fragrance, and can replace relatively unstable floral fragrances. Therefore, the synthesis of the neryl ether by a chemical method has important application value. At present, two methods are mainly adopted for synthesizing the nerol, wherein one method is to obtain the corresponding nerol through three steps of reaction of bromination-alkoxylation, elimination and cyclization by taking the nerol/geraniol as raw materials. The brominating reagent used in the method is expensive, the production cost is high, the comprehensive yield of the three-step reaction is not higher than 70%, and the kettle liquid amount is large. The second method adopts isopentenyl aldehyde and isopentenyl alcohol to cyclize directly Prins for one step to obtain neryl ether. For example, in the method for synthesizing the nerol in the patent CN116041299A, a liquid strong acid is used as a catalyst, a molecular sieve is used as an auxiliary agent, and finally the nerol product can be obtained with a yield of 90%. The catalyst of the second method is cheaper than that of the first method, is simple to operate and is easy for industrial production. The final yield of the reaction is 90%, and about 10% of by-product 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan is mainly generated in the reaction process. The reaction mechanism is as follows, isopentenyl aldehyde and isopentenyl alcohol react to generate an intermediate A, the intermediate A is eliminated by beta-H to obtain neryl ether, but the intermediate also can react with isopentenyl alcohol continuously to obtain a byproduct 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxetan, and the byproduct is about 10 percent. How to convert the by-products into useful nerol products is therefore critical to increase the reaction yield. Through the structural analysis of byproducts, the byproducts are ether substrate structures, the traditional liquid acid such as hydroiodic acid aqueous solution is used for carrying out ether hydrolysis, but the liquid acid has strong corrosivity and high requirements on equipment, and a large amount of wastewater is generated by post-treatment, the three reaction wastes are high, in conclusion, the traditional hydroiodic acid liquid acid is used for not only having high requirements on equipment, but also requiring a large amount of alkaline water for neutralizing the acid solution, the three production wastes are high, the industrialization cost is high, and in addition, the yield is generally not high, so that the method is unfavorable for industrial production. Therefore, if the 4-methyl-4- [ (3-methylbut-3-en-1-yl) oxy ] -2- (2-methylprop-1-en-1-yl) oxetane can be used as a raw material to efficiently synthesize the neryl ether, the method has important promotion significance for the industrialization of the neryl ether. Disclosure of Invention In view of the shortcomings of the prior art, the invention aims to provide a method for synthesizing nerol by using 4-methyl-4- [ (3-methylbutan-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy cyclohexane, which uses SO 42--Fe2O3-La2O3/SBA-15 solid acid as a catalyst, and successfully synthesizes nerol with high efficiency by using a raw material of a byproduct 4-methyl-4- [ (3-methylbutan-3-en-1-yl) oxy ] -2- (2-methylpropan-1-en-1-yl) oxy cyclohexane through screening reaction temperature, reaction pressure, auxiliary agent and reaction flow rate. The method has low requirements on equipment, mild reaction conditions, high reaction speed and high production efficiency, and is easy to realize industrial production. The invention is realized by the following technical scheme: A process