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CN-117623894-B - Condensation method of cyclopentanone and aldehyde and catalyst used in condensation method

CN117623894BCN 117623894 BCN117623894 BCN 117623894BCN-117623894-B

Abstract

The invention discloses a condensation method of cyclopentanone and aldehyde and a catalyst used in the condensation method. The condensation method takes cyclopentanone and aldehyde as raw materials, and carries out condensation reaction in the presence of a catalyst, wherein the catalyst is a supported catalyst, hydrotalcite grows in situ on a solid acid carrier, and the solid acid carrier is prepared by roasting, and has a macroporous or mesoporous structure. Preferably, the solid acid support is selected from metal oxides or modified molecular sieves. The condensation method has the advantages that the reaction selectivity and the reaction yield of target products are obviously improved, the condensation reaction rate is also accelerated, the condensation method only needs one-step reaction, the use of a large amount of acid and alkali is not involved, and the post-treatment is simple.

Inventors

  • ZHU JIAN
  • YING SIBIN
  • LUO GONGYU
  • ZHAN YIHUA
  • Xu Xindie
  • YING MINGJUN
  • LIU GANG
  • XU DONG
  • LOU CHUNQING

Assignees

  • 浙江新化化工股份有限公司
  • 宁夏新化化工有限公司

Dates

Publication Date
20260508
Application Date
20231121

Claims (15)

  1. 1. A condensation method of cyclopentanone and aldehyde is characterized in that cyclopentanone and aldehyde are used as raw materials in the condensation method, and condensation reaction is carried out in the presence of a catalyst, wherein the catalyst is a supported catalyst, hydrotalcite grows in situ on a solid acid carrier, and the solid acid carrier is prepared by roasting, and has a macroporous or mesoporous structure; The solid acid carrier is selected from metal oxide or modified molecular sieve; The metal oxide is selected from one or more of TiO 2 、CeO 2 、ZrO 2 、MoO 3 、Nb 2 O 3 , is prepared by a preparation method comprising the steps of mixing and reacting a compound of corresponding metal elements, a surfactant, a complexing agent, phosphoric acid and a solvent to obtain a precursor, removing the solvent in the precursor, and roasting to obtain the metal oxide, wherein the modified molecular sieve is one or more of a ZSM-5 molecular sieve, a Y-type molecular sieve, a Beta molecular sieve, an SBA-15 molecular sieve, a TS-1 molecular sieve and a Ti-MWW molecular sieve.
  2. 2. The method for condensing cyclopentanone with aldehyde according to claim 1, wherein the metal oxide is TiO 2 , and the compound of the corresponding metal element is one or more selected from titanium tert-butoxide, methoxy titanium, tetrabutyl titanate, isopropyl titanate, tetraethyl titanate, and titanium acetylacetonate.
  3. 3. The method according to claim 1, wherein the metal oxide is CeO 2 , the compound of the corresponding metal element is selected from one or more of cerium propionate, cerium acetate, cerium nitrate and cerium tert-butoxide, or the metal oxide is ZrO 2 , and the compound of the corresponding metal element is selected from one or more of zirconium propionate, zirconium acetate, zirconium nitrate, zirconyl nitrate, zirconium ethoxide, zirconium tert-butoxide and zirconium n-butoxide.
  4. 4. The method for condensing cyclopentanone with aldehyde according to claim 1, characterized in that the metal oxide is MoO 3 , the compound of the corresponding metal element is selected from one or more of molybdenum acetate, ammonium molybdate, molybdenum acetylacetonate, ammonium phosphomolybdate, or Nb 2 O 3 , the compound of the corresponding metal element is selected from one or more of niobium oxalate, niobium ethoxide, ammonium niobate oxalate hydrate.
  5. 5. The method according to claim 1, wherein the surfactant is a nonionic surfactant and is selected from one or more of polyethylene oxide-polypropylene oxide diblock copolymer, polyethylene oxide-polybutylene oxide diblock copolymer, polyethylene oxide-polystyrene diblock copolymer, polyethylene oxide-polymethyl methacrylate diblock copolymer, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, polypropylene oxide-polyethylene oxide-polypropylene oxide triblock copolymer, and/or the complexing agent is selected from one or more of citric acid, acetylacetone, ethylenediamine tetraacetic acid, and/or the solvent is selected from one or more of ethanol, methanol, isopropanol, butanol, and water.
  6. 6. The method for condensing cyclopentanone with aldehyde according to claim 1, wherein the molar ratio of the compound of the corresponding metal element, the surfactant, the complexing agent, and the phosphoric acid is 1:0.1-10:3-100:0.1-5, and/or the reaction temperature is 20-80 ℃, the calcination temperature is 300-800 ℃, and/or the reaction time is 0.5-24 h, and the calcination time is 0.5-24 h.
  7. 7. The method for condensing cyclopentanone with an aldehyde according to claim 1, wherein the acid is selected from one or more of oxalic acid, boric acid, acetic acid, and propionic acid, and/or the base is selected from one or more of sodium hydroxide, sodium carbonate, ethylenediamine, triethylamine, n-butylamine, piperidine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.
  8. 8. The condensation method of cyclopentanone and aldehyde according to claim 1, characterized in that the modified molecular sieve is prepared by a preparation method comprising the steps of 1) acid-treating the molecular sieve with an acid solution, washing, drying and roasting to obtain an acid-treated molecular sieve, and 2) alkali-treating the acid-treated molecular sieve with an alkali solution, washing, drying and roasting to obtain the modified molecular sieve.
  9. 9. The condensation method of cyclopentanone and aldehyde according to claim 8, characterized in that the acid solution has a molar concentration of 0.05-5 mOl/L, the acid treatment is performed at 30-180 ℃, and/or the acid treatment is performed for 0.5-48 hours, and/or the alkali solution has a molar concentration of 0.05-5 mOl/L, the alkali treatment is performed at 30-180 ℃, and/or the alkali treatment is performed for 0.5-48 hours.
  10. 10. The condensation method of cyclopentanone and aldehyde according to claim 1, wherein the catalyst is prepared by a preparation method comprising the steps of mixing the solid acid carrier with water to obtain a mixture, adding an alkali solution and a metal salt solution dropwise into the mixture, performing precipitation reaction, aging, washing, and drying to obtain the catalyst.
  11. 11. The method for condensing cyclopentanone with aldehyde according to claim 10, wherein the alkali solution is a mixed solution of sodium hydroxide and sodium carbonate, wherein the concentration of sodium hydroxide is 0.01-5.0 mol/L, the concentration of sodium carbonate is 0.01-5.0 mol/L, and/or the metal salt solution is a mixed solution of aluminum nitrate and divalent metal nitrate, wherein the divalent metal nitrate is selected from one or more combinations of Mg(NO 3 ) 2 、Ca(NO 3 ) 2 、Ba(NO 3 ) 2 、Co(NO 3 ) 2 、Mn(NO 3 ) 2 、Zn(NO 3 ) 2 , wherein the concentration of aluminum nitrate is 0.1-3.0 mol/L, and the concentration of divalent metal nitrate is 0.1-5.0 mol/L.
  12. 12. The method for condensing cyclopentanone with an aldehyde according to claim 1, characterized in that the catalyst contains 10% -90% by weight of solid acid carrier.
  13. 13. The condensation method of cyclopentanone and aldehyde according to claim 1, characterized in that the calcination temperature is 350-700 ℃ and/or the calcination time is 0.5-24 h.
  14. 14. The method for condensing cyclopentanone with an aldehyde according to claim 1, wherein the aldehyde is selected from one or more of valeraldehyde, caproaldehyde, enantholdehyde, caprylic aldehyde, pelargonic aldehyde, capric aldehyde.
  15. 15. The catalyst of any one of claims 1-14.

Description

Condensation method of cyclopentanone and aldehyde and catalyst used in condensation method Technical Field The invention relates to a condensation method of cyclopentanone and aldehyde and a catalyst used in the condensation method. Background The cyclopentanone is condensed with aldehyde, and then hydrogenated and oxidized to expand the ring to prepare a series of delta lactones. The butyrolactone has strong and durable cream aroma, is an important raw material for preparing milk and cream essence, and is widely used for preparing spices such as coconuts, strawberries, peaches and the like. The condensation of cyclopentanone and aldehyde can be divided into two steps, 1) the formation of an intermediate from cyclopentanone and aldehyde under the action of a base, and 2) the dehydration of the intermediate under the action of an acid to form a product. In industry, the first condensation reaction is catalyzed by sodium hydroxide aqueous solution, and the second dehydration reaction is catalyzed by oxalic acid and other organic acids. However, the use of a large amount of acid or alkali makes the post-reaction treatment complicated, and the residual acid or alkali can cause the polymerization of the product, thereby reducing the reaction yield. Taking condensation of cyclopentanone and n-valeraldehyde as an example, previous researches show that the base-catalyzed condensation reaction is generally that the base is firstly combined with alpha-H in the cyclopentanone to form an enol anion, the generated enol anion is used as a nucleophilic reagent to attack carbonyl carbon atom with positive charge of the n-valeraldehyde, and the intermediate 2- (1-hydroxypentyl) cyclopentanone is generated after the addition reaction. Dehydrating the 2- (1-hydroxy amyl) cyclopentanone under the action of acid to obtain the target product of the 2-amyl idene cyclopentanone. The reaction mechanism is as follows: Since cyclopentanone, n-valeraldehyde, and the 2- (1-hydroxypentyl) cyclopentanone intermediate and the 2-pentylidene cyclopentanone target product all have active alpha-H and carbonyl, cross condensation between aldehyde and ketone can occur between them, and self condensation of aldehyde and ketone can also occur, so that the selectivity of the reaction is greatly reduced, and the reaction selectivity is difficult to realize at high level. In particular, as the reaction proceeds, the concentrations of the 2- (1-hydroxypentyl) cyclopentanone intermediate and the 2-pentylidene cyclopentanone target product increase, which are susceptible to condensation with n-valeraldehyde or cyclopentanone starting material, and the fraction of by-products is about 80% of the total by-products, and the longer the reaction time, the more pronounced the side reaction. According to the above generation mechanism of the target product of 2-pentylene cyclopentanone, the reaction needs to be catalyzed by acid and alkali, so that the reaction in the prior art needs to be divided into two steps, the reaction process of cyclopentanone and n-valeraldehyde is reversible, and the two steps of reaction are unfavorable for the forward reaction, so that the reaction rate is reduced, the residence time of reactants, intermediates and products in the reaction system is increased, and side reactions are easy to initiate. Disclosure of Invention In view of the shortcomings and drawbacks of the prior art, the present invention provides an improved condensation process of cyclopentanone with an aldehyde. The condensation method has the advantages that the reaction selectivity and the reaction yield of target products are obviously improved, the condensation reaction rate is also accelerated, the condensation method only needs one-step reaction, the use of a large amount of acid and alkali is not involved, and the post-treatment is simple. In order to achieve the above purpose, the invention adopts the following technical scheme: The condensation method of cyclopentanone and aldehyde takes cyclopentanone and aldehyde as raw materials, and carries out condensation reaction in the presence of a catalyst, wherein the catalyst is a supported catalyst, hydrotalcite grows in situ on a solid acid carrier, and the solid acid carrier is prepared by roasting, and has a macroporous or mesoporous structure. In the present invention, macropores refer to pores having a pore diameter of more than 50nm, and mesopores refer to pores having a pore diameter of 2 to 50nm, which are also called mesopores. The inventor finds that the inside of the solid acid carrier with a macroporous or mesoporous structure is provided with a developed pore canal structure, the developed pore canal structure is favorable for the diffusion of an intermediate and a final target product generated by condensation of cyclopentanone and aldehyde, the residence time of the intermediate and the final target product in a reaction system is obviously shortened, side reactions are obviously inhibited,