Method for preparing menthone from citronella aldehyde and catalyst system for the method

A technology of catalyst and menthone, which is applied in the field of preparation of menthone, can solve the problems of low selectivity of target products, increased cost of raw materials, increased difficulty, etc.

Active Publication Date: 2019-05-03
WANHUA CHEM GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The process is simple and environmentally friendly, but the selectivity of the target product is low, and the yield is only 70%, which leads to an increase in the cost of raw materials and increases the difficulty of separating products with higher purity in the later stage

Method used

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  • Method for preparing menthone from citronella aldehyde and catalyst system for the method
  • Method for preparing menthone from citronella aldehyde and catalyst system for the method
  • Method for preparing menthone from citronella aldehyde and catalyst system for the method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0058] Catalyst 0.5%Zn-1%Ru / Al 2 o 3 Preparation and reduction process:

[0059] Step a) with 50g Al 2 o 3 The carrier is fully dispersed in 250g of water, and maintains a highly dispersed state; in step b), the active components ruthenium and zinc are added simultaneously in the solution form of their metal salts ruthenium chloride and zinc chloride (5wt% aqueous solution, the same below), Wherein the addition of ruthenium chloride and zinc chloride is respectively 1.35g and 0.52g; step c) in order to precipitate the catalytically active component on the carrier, slowly add 0.5mol / L NaOH saturated solution, when the pH stability of the mixed solution At 9 o'clock, stop dripping lye; step d) after the active component is fully precipitated, the catalyst is separated from the water phase; e) the catalyst filter cake obtained is then dried under reduced pressure or inert gas, and then the dried The catalyst is calcined at a calcination temperature of 400°C for 5 hours to obt...

Embodiment 2

[0063] Catalyst 0.6%Zn-2%Ru / Al 2 o 3 Preparation and reduction process:

[0064] Step a) with 50g Al 2 o 3 The carrier is fully dispersed in 250g of water and remains in a highly dispersed state; in step b), the active components ruthenium and zinc are added simultaneously in the form of a solution of their metal salts ruthenium chloride and zinc chloride, wherein ruthenium chloride and zinc chloride The addition amount of each is 2.7g and 0.63g; step c) in order to precipitate the catalytically active component on the carrier, slowly add 0.5mol / LNaOH saturated solution, when the pH stability of the mixed solution is at 9, stop dripping the lye ; Step d) After the active components are fully precipitated, the catalyst is separated from the water phase; e) Then the obtained catalyst filter cake is dried under reduced pressure or inert gas, and then the dried catalyst is calcined at a calcining temperature of 450°C , calcined for 8 hours to obtain a catalyst precursor; f) We...

Embodiment 3

[0068] Catalyst 0.7%Zn-3%Ru / Al 2 o 3 Preparation and reduction process:

[0069] Step a) with 50g Al 2 o 3 The carrier is fully dispersed in 250g of water and remains in a highly dispersed state; in step b), the active components ruthenium and zinc are added simultaneously in the form of a solution of their metal salts ruthenium chloride and zinc chloride, wherein ruthenium chloride and zinc chloride The addition amount of each is 4.05g and 0.73g; step c) in order to precipitate the catalytically active component on the carrier, slowly add 0.5mol / LNaOH saturated solution, when the pH stability of the mixed solution is at 9, stop dripping the lye ; Step d) After the active components are fully precipitated, the catalyst is separated from the water phase; e) Then the obtained catalyst filter cake is dried under reduced pressure or inert gas, and then the dried catalyst is calcined at a temperature of 480°C , calcined for 18 hours to obtain a catalyst precursor; f) Weigh 100 ...

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Abstract

The invention discloses a synthesis method of menthone and a catalyst system for the method. The method uses a heterogeneous catalyst and adds a small amount of auxiliaries, so that the citronella aldehyde undergoes intramolecular cyclization reaction to directly obtain menthone, the conversion rate can reach more than 90%, and the chemical selectivity of the reaction is more than 96%.

Description

technical field [0001] The invention relates to the field of preparation of menthone, in particular to a method for preparing menthone from citronellal using a heterogeneous catalyst and a catalyst system used in the method. Background technique [0002] As a naturally occurring cyclic terpene ketone, L-menthone is one of the main components of Asiatic peppermint and American peppermint oil. Because of its cooling and cooling effects, it is widely used in flavor formulations and seasonings, and also in medicine. widely used. Racemic menthone is also widely used in the deployment of refreshing flavors. Therefore, the synthesis of menthone has attracted people's attention. [0003] There are many ways to synthesize menthone, mainly based on the oxidation of menthol, using stoichiometric oxidation systems such as chromate, permanganate and hypochlorite, such as KazuhikoSato et al. in J.Am.Chem.Soc. In the article published on 1997,119,12386, hydrogen peroxide was used as an ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/407C07C45/67B01J23/60
Inventor 王联防董菁张永振黎源方文娟李晶刘照苏黎明
Owner WANHUA CHEM GRP CO LTD
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