JP4709356B2 - Method for producing high epimer alkyl jasmonates - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of continuously producing alkyl jasmonates having a high epimer concentration from alkyl esters having a low epimer concentration.
More specifically, the present invention relates to a method for efficiently producing high-epimer concentration alkyl jasmonate excellent in quality such as odor and the like continuously from low-epimer concentration alkyl jasmonate.
[0002]
[Prior art]
Alkyl jasmonates such as methyl dihydrojasmonate (hereinafter abbreviated as “MDJ”) and methyl jasmonate (in the present invention, alkyl dihydrojasmonate and alkyl jasmonate are collectively referred to as “alkyl jasmonate”) are: Useful as a fragrance.
In particular, it is known that MDJ having a high epimer concentration exhibits excellent odor intensity and is useful as an aroma compound (composition).
[0003]
Conventionally, in order to produce MDJ with a high epimer concentration, a mixture of the cis isomer and the trans isomer obtained by synthesis is heat-treated in the presence of an isomerization catalyst to convert a part of the trans isomer to the cis isomer. Then, after making the cis isomer content about 10%, a method of increasing the cis isomer content to about 20 to 50% by removing the trans isomer by distillation was employed.
However, in the simple distillation that has been adopted so far, the low epimer concentration fraction distilled from the top of the column has a low product price, and most of it is discarded. It was. In addition, the products obtained by simple distillation had a problem in quality due to variations in the epiconcentration and odor quality of each lot.
[0004]
Furthermore, in order to distill a product having a high epimer concentration from the top of the distillation column, it is necessary to increase the temperature of the kettle (column bottom), and a long time is required for distillation. For this reason, decomposition and isomerization of MDJ occur during distillation, reducing the yield and odor quality.
Moreover, since the kettle residue after distillation contains a large amount of high-boiling impurities, the degree of coloring is large, the quality of odor and the like is poor, and there is a problem in producing a product.
[0005]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to continuously and efficiently produce alkyl jasmonate having a high epimer concentration from an alkyl jasmonate having a low epimer concentration without incurring problems of coloring or odor quality. It is to provide a method.
[0006]
[Means for Solving the Problems]
As a result of diligent studies to achieve the above object, the present inventors sequentially apply a fraction of an alkyl jasmonate fraction having a low epimer concentration to (i) isomerization, (ii) concentrated distillation, and (iii) thin film distillation. As a result, it has been found that alkyl jasmonate having a high epimer concentration can be obtained continuously and efficiently, and the present invention has been completed based on this finding.
[0007]
Thus, according to the present invention, there is provided a continuous production method of alkyl jasmonates of the following (1) to ( 3 ).
(1) (i) The raw material is an alkyl jasmonate fraction having an epimer concentration of less than 10% by weight obtained as a low-boiling fraction in purification distillation of crude alkyl jasmonate , and a temperature of 160 to 190 ° C. and a pressure of −90. isomerization step to increase the epicatechins concentration above 10% by the condition of ~-101.3 kPa the continuous isomerization reaction, the product obtained in (ii) isomerization step (i), concentrated distiller High epimer by concentrating the epimer concentration to 20% or more by continuous concentration distillation at a pressure of −90 to −101.3 kPa, a column bottom temperature of 170 to 185 ° C., and a column top temperature of 100 to 110 ° C. A concentrated distillation step for obtaining a crudely purified fraction having a concentration, and (iii) a crude purified fraction having a high epimer concentration obtained in the concentrated distillation step (ii) is subjected to a pressure of −90 to −101.3 kPa, a treatment temperature of 135 to Thin film distillation at 145 ° C , high An alkyl jasmonate having an epimer concentration of 20% or more, comprising a thin film distillation step of continuously removing a boiling-point impurity-containing fraction and continuously extracting alkyl jasmonates from the upper part of the thin film distillation apparatus. A continuous production method of the kind.
(2) (ii) In the concentration distillation step, the amount extracted from the top of the concentration distillation apparatus is 80 to 90% by weight with respect to the supply amount to the concentration distillation apparatus. A continuous process for producing alkyl jasmonates having a body concentration of 20% or more.
(3) (iii) In the thin film distillation step, the amount extracted from the upper part of the thin film distillation apparatus is a ratio of 9.5 to 18.5% by weight with respect to the supply amount to the concentration distillation apparatus. (2) A method for continuously producing alkyl jasmonates having an epimer concentration of 20% or more.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the production method of the high epimer concentration alkyl jasmonate according to the present invention will be described in more detail using MDJ as an example.
The continuous production method of the high epimer concentration MDJ of the present invention is obtained by (i) an isomerization step using the low epimer concentration MDJ as a raw material, (ii) a concentration distillation step of the isomerized product, and (iii) concentration. It consists of a thin-film distillation step of the obtained high-epimer concentration crude purified MDJ.
[0009]
The MDJ having a low epimer concentration used as a raw material in the production method of the present invention is not particularly limited. Usually, in the MDJ purification distillation, the fraction having an epimer concentration of less than 10% extracted from the top of the purification distillation apparatus is used. Minutes are used. The MDJ raw material having a low epimer concentration can be increased to an epimer concentration of 10% or more by the continuous isomerization reaction in the (i) isomerization step.
[0010]
The isomerization reaction can be performed by heating in the presence of a base or an acid. Here, as the base, carbonates, bicarbonates, hydroxides, and the like of alkali metals and alkaline earth metals are preferably used. Specific examples thereof include sodium carbonate, potassium carbonate, sodium bicarbonate, hydrogen carbonate. Alkali metal carbonates and hydrogen carbonates such as potassium; alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; magnesium hydroxide and hydroxide Examples thereof include hydroxides of alkaline earth metals such as calcium. As the acid, an acidic ion exchange resin, an inorganic acid, an organic acid, or the like is used. Specific examples thereof include ion exchange resins such as diaion, dowex, and amberlite; inorganics such as hydrochloric acid, sulfuric acid, and phosphoric acid. Acids: Organic acids such as acetic acid, tosylic acid and oxalic acid can be mentioned.
The amount of these bases or acid catalysts is 10 to 1,000 ppm with respect to MDJ.
[0011]
The isomerization reaction can be carried out without a solvent, but a solvent may be present. The reaction temperature is usually about 160 to 190 ° C. The pressure of the reaction system is not particularly limited, but is about -90 to -101.3 kPa. Moreover, reaction time is about 5 to 11 hours normally.
The isomerization reaction product is sent to a concentration distillation apparatus, and crude purified MDJ having an epimer concentration increased to 20% or more is continuously extracted from the bottom of the concentration distillation apparatus [(ii) concentration distillation step]. The MDJ fraction having a low epimer concentration distilled from the upper part of the concentration distillation apparatus can be recycled as a part of the raw material of the above (i) isomerization step.
[0012]
The highly purified crude MDJ with a high epimer concentration extracted from the lower part of the concentration distillation apparatus is then sent to a thin film distillation apparatus, where a product MDJ with a high purity and a high epimer concentration is continuously extracted from the upper part [ (Iii) Thin film distillation step]. The remainder containing high boiling impurities is continuously extracted from the lower part of the thin film distillation apparatus.
[0013]
Hereinafter, the continuous production method of high epimer concentration MDJ of the present invention will be described more specifically and in detail with reference to the accompanying drawings.
(I) The low epimer concentration MDJ, which is a raw material of the isomerization process, is, for example, a fraction distilled from the top of the distillation column when the crude MDJ sent from the MDJ synthesis system is purified and distilled. is there. That is, crude MDJ having an MDJ content of 97 to 98% by weight and an epimer concentration of 9 to 11% sent from the MDJ synthesis system is supplied to the middle stage of the purification distillation column 2. Since distillation in the purification distillation column 2 is distillation of a high boiling point compound, it is usually performed under reduced pressure. Specifically, the degree of vacuum is generally −90 to −101.3 kPa, the tower top temperature is 100 to 110 ° C., and the tower bottom temperature is about 165 to 175 ° C.
[0014]
From the top of the purification distillation column 2, a low-boiling fraction (MDJ content of about 90% by weight, epimer concentration of 2 to 8%) of about 10 to 20% by weight of the amount supplied to the purification distillation column is extracted. The low epimer concentration / low boiling fraction 3 is fed to the (i) isomerization step of the present invention as a raw material. If desired, a part of the low epimer concentration / low boiling fraction 3 can be recycled and returned to the feedstock system to the purification distillation apparatus 2.
On the other hand, from the bottom of the purification distillation column 2, the high boiling point component 5 having an MDJ content of 99.0 to 99.5% by weight and an epimer concentration of 10 to 12% is supplied to the purification distillation column. It is extracted at a rate of about 90 to 80% by weight and is continuously supplied to the thin-film distillation apparatus 6.
[0015]
Through the thin film distillation, from the top of the thin film distillation apparatus 6, the MDJ content of 99.5% by weight or more and the product MDJ having an epimer concentration of 10 to 12% is continuously about 77 to 87% of the amount supplied to the purification distillation column or the like. %, And the bottom 7 containing high-boiling impurities is continuously withdrawn from the bottom of the thin-film distillation apparatus 6 at a rate of about 3 to 13% by weight of the amount supplied to the purification distillation column or the like. This pot residue 7 can be taken out of the system and returned to the supply system 4 to the purification distillation column 2 as needed. The specific temperature and pressure employed in the thin film distillation apparatus 6 are generally such that the degree of vacuum is −90 to −101.3 kPa or less and the processing temperature is about 135 to 145 ° C.
[0016]
From the isomerization reactor 9, the gaseous product 10 whose epimer concentration is increased to 10% or more, usually 10 to 12%, is continuously present at a rate of about 10 to 20% by weight of the amount supplied to the purification distillation column. And is sent to the concentration distillation apparatus 11. Concentrated distillation is generally performed at a pressure of −90 to −101.3 kPa, a tower bottom temperature of 170 to 185 ° C., and a tower top temperature of 100 to 110 ° C. Crude refined MDJ whose epimer concentration is increased to 20% or more, usually 30 to 45% by concentration distillation, is extracted from the bottom of the column at a rate of about 10 to 20% by weight of the amount supplied to the concentration distillation apparatus.
[0017]
A low epimer concentration, for example, a fraction 13 having an epimer concentration of 2 to 7% is continuously extracted from the upper part of the concentration distillation apparatus 11 at a rate of about 80 to 90% by weight of the amount supplied to the concentration distillation apparatus. . Preferably, a portion 15 of the extracted low epimer fraction 13 is returned as a portion 4 of the feedstock of the purification distillation apparatus 2 and the remaining portion 14 is fed to the feed system to the isomerization reactor 9. Returned.
The highly purified crude MDJ withdrawn from the bottom of the concentration distillation apparatus 11 is sent to the thin film distillation apparatus 16 and thin film distilled. The processing conditions in the thin-film distillation apparatus 16 are usually a pressure of −90 to −101.3 kPa and a processing temperature of about 135 to 145 ° C.
[0018]
From the upper part of the thin film distillation apparatus 16, high purity MDJ17 having an epimer concentration of 20% or more, usually 30 to 45%, is a product at a ratio of about 9.5 to 18.5% by weight of the supply amount to the concentration distillation apparatus. Extracted. From the lower part of the thin-film distillation apparatus 16, the residue 18 containing high-boiling impurities is extracted at a rate of about 0.5 to 1.5% by weight of the amount supplied to the concentration distillation apparatus. Is returned as a part 4 of the feedstock to the purification distillation apparatus 2.
[0019]
【The invention's effect】
According to the continuous high concentration MDJ production method of the present invention including the above (i) isomerization step, (ii) concentration distillation step, and (iii) thin film distillation step, the following effects are exhibited.
(I) Alkaline jasmonate Alkaline jasmonate having a high epimer concentration can be efficiently obtained from an alkyl jasmonate having a low epimer concentration distilled in the distillation purification step.
(B) Since the low-boiling fraction distilled in the step of distillation purification of alkyl jasmonates is used as a raw material, the amount of high-boiling impurities produced in the purification process of the present invention is very small.
(C) Since it is continuously manufactured, the quality of epimer purity and odor in the high epimer concentration alkyl jasmonate products is stabilized.
[0020]
(D) In the epi-enrichment concentration distillation process, the kettle residue continuously extracted from the bottom of the column is commercialized, so the heating time is relatively short, and the decomposition and isomerization of alkyl jasmonates during concentration Reduces odor quality.
(E) Trace high-boiling impurities and off-flavor components remaining in the kettle residue after distillation and concentration can be easily removed by thin-film distillation.
(F) When the low-epimer alkyl jasmonate fraction distilled in a large amount in the concentration distillation step is returned to the isomerization reactor again and recycled, the productization rate is greatly improved.
(G) High-boiling fractions removed by thin-film distillation and / or wastes in the case of re-distilling and distilling fractions extracted to remove low-boiling fractions from low-boiling fractions of concentrated distillation There are very few.
[0021]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not restrict | limited at all by these. In the examples, “%” and “parts” represent “% by weight” and “parts by weight”, respectively, unless otherwise specified.
〔Example〕
The crude MDJ was isomerized and purified using the isomerization apparatus and the purification apparatus shown in FIG.
[0022]
MDJ having a purity of 97.5% and an epimer concentration of 9 to 11% sent from the synthesis step was supplied to the upper middle part of the purification distillation column at a rate of 100 parts by weight per hour. The purification distillation column 2 is a packed column (Sulzer packed column manufactured by Sumitomo Heavy Industries, Ltd.) having a sulzer packing (a pie-shaped packing formed by integrating mesh strips made of stainless steel in parallel).
The purification distillation column 2 was operated at a column top temperature of 105 to 107 ° C., a column bottom temperature of 171 to 173 ° C., and a pressure of −101.1 kPa or less.
The low boiling fraction 3 was continuously withdrawn from the top of the purification distillation column 2 at a rate of 15 parts by weight per hour. The MDJ content in the extracted fraction was about 90%, and the epimer concentration was 2 to 4%. A part of this tower top fraction (7 parts by weight per hour) was recycled to the feedstock system to the purification distillation column 2, and the remaining part (8 parts by weight per hour) was sent to the isomerization step.
[0023]
MDJ having an epimer concentration of 10 to 12% was continuously extracted from the bottom of the purification distillation column 2 and led to the thin-film distiller 6 at a rate of 85 parts by weight per hour. The temperature of the vapor distilled by thin film distillation was 140 ° C., and the internal pressure of the apparatus was −101.1 kPa. 81 parts by weight of product MDJ having a purity of 99.7% and an epimer concentration of about 11% was obtained from the top of the thin-film still 6. The residue 7 was continuously withdrawn from the bottom of the distiller at a rate of 4 parts by weight per hour and recycled to the feedstock system for the purification distillation column 2.
[0024]
The isomerization reaction was performed at a temperature of 175 to 177 ° C., a pressure of −95 to −101.1 kPa, and an average residence time of about 8 hours in the presence of 100 ppm of sodium carbonate catalyst relative to MDJ. The isomerization reaction was performed together with 33 parts by weight of return from the upper part of the concentration distiller described later. The gaseous product 10 withdrawn from the isomerization reactor 9 was continuously sent to the concentration distillation column 11 at a rate of 41 parts by weight per hour. The epimer concentration in the gaseous product 10 was 10 to 12.5%.
The gaseous product 10 from the isomerization reactor 9 was concentrated and distilled by the concentration distiller 11 at a tower bottom temperature of 175 to 178 ° C., a tower top temperature of 105 to 107 ° C., and a pressure of −95 to −101.1 kPa.
[0025]
A low boiling fraction 13 was extracted from the upper part of the concentrated still 11 at a rate of 35 parts by weight per hour. The epimer concentration in the low boiling fraction 13 was about 3%. The low-boiling fraction 13 returns a part 15 (2 parts by weight per hour) to the feedstock system 4 to the refining distiller 2 and the remaining part 14 (33 parts by weight per hour) to the supply system to the isomerization reactor 9. Returned.
The concentrate 12 was extracted from the bottom of the concentration distiller 11 at a rate of 6 parts by weight per hour and sent to the thin film distiller 16. The epimer concentration in the concentrate 12 was 38 to 43%.
The temperature of the steam distilled by thin film distillation was 140 ° C., and the internal pressure was −95 to −101.1 kPa. The residue 18 was continuously extracted from the bottom of the thin-film distiller at a rate of 0.3 parts by weight per hour and recycled to the feedstock system to the purification distillation column 2. Within 10 hours from the start of the thin film distillation, the desired high epimer concentration product MDJ was obtained from the top of the thin film still 16 at a rate of 5.7 parts by weight per hour. The product MDJ had a purity of 99.7% and an epimer concentration of 40.5%.
[0026]
(Product evaluation)
The MD value (sample A) obtained from the top of the thin-film distillation apparatus 16 and having a purity of 99.7% and an epimer concentration of 40.5% was measured according to ASTM D1209-1980. It was -0.3. On the other hand, the a value of the concentrate (sample B) having an epimer concentration of 38 to 43% extracted from the bottom of the concentration distillation apparatus was 0.5 to 1.0. Further, when samples A and B were evaluated for odor by the following method, they were 4.8 for sample A and 4.0 for sample B.
[0027]
[Odor evaluation method]
A sensory test with a standard sample was conducted by five panelists, and the scores of the five persons were averaged to evaluate the odor.
Standard samples and their scores are as follows.
1: A thing with a strange odor 3: A thing with a slightly strange odor 5: No problem [0028]
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory diagram showing a high-boiling point fragrance refining process of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 MDJ crude raw material 2 Refinement distillation column 3 Low epimer concentration and low boiling point fraction from the top 4 Recycled fraction 5 Extracted liquid from the bottom of the column 6 Thin film distiller 7 High boiling point fraction extracted from the bottom 8 Product MDJ
9 Isomerization reactor 10 Gaseous isomerization reaction product 11 Concentrated distiller 12 Concentrate (high epimer concentration / crude refined MDJ)
13 Low epimer concentration and low boiling fraction 14 Low epimer concentration fraction 15 returned to the isomerization reactor 15 Low epimer concentration fraction 16 returned to the refined distiller 16 Thin film distiller 17 High epimer concentration product MDJ
18 High-boiling fraction returned to the refinery

Claims (3)

(I) The raw material is an alkyl jasmonate fraction having an epimer concentration of less than 10% by weight obtained as a low-boiling fraction in the purification distillation of crude alkyl jasmonate , and a temperature of 160 to 190 ° C. and a pressure of −90 to −101. The isomerization step for increasing the epimer concentration to 10% or more by performing a continuous isomerization reaction under the condition of 3 kPa , (ii) the product obtained in the isomerization step (i) is concentrated using a concentration distillation apparatus. Concentrated and distilled continuously at a pressure of −90 to −101.3 kPa, a tower bottom temperature of 170 to 185 ° C., and a tower top temperature of 100 to 110 ° C. to extract a fraction having a low epimer concentration from the tower top, and an epimer concentration concentrate distillation step to obtain from the bottom a crude fraction high epicatechins concentrations was concentrated more than 20% and a crude fraction of the high epicatechins concentrations obtained in (iii) concentrating the distillation step (ii) , Pressure -90 to -101.3 kPa And a thin film distillation step of continuously removing high-boiling impurity-containing fractions at a treatment temperature of 135 to 145 ° C. and continuously extracting alkyl jasmonates from the upper part of the thin film distillation apparatus. A process for continuously producing alkyl jasmonates having an epimer concentration of 20% or more. (Ii) In the concentration distillation step, the extraction amount from the top of the concentration distillation apparatus is a ratio of 80 to 90% by weight with respect to the supply amount to the concentration distillation apparatus. A continuous process for producing the above alkyl jasmonates. (iii) In the thin film distillation step, the amount extracted from the upper part of the thin film distillation apparatus is a ratio of 9.5 to 18.5% by weight with respect to the supply amount to the concentration distillation apparatus. A continuous process for producing alkyl jasmonates having an epimer concentration of 20% or more.

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