JPH0399072A - Preparation of 5-hydroxymethyl-2-furan carboxyaldehyde - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention heats and dehydrates hexose in the presence of an acid catalyst to produce 5-hydroxymethyl-2-furancarpoxyaldehyde ( The present invention relates to a method for producing 1 (hereinafter referred to as MF).

11MF is a polyfunctional furan compound obtained from hexose, and is attracting attention as a starting material for polymer monomers, medicines and agrochemicals, fragrances, etc. [Prior art and problems to be solved by the invention] Many methods have been proposed for obtaining IMF from hexose under acid catalyst.
There are no examples of IMF being isolated. For example, as an example of reactions to IMF and purification of IMF, the Journal of Chemical Technology and Biotechnology (Journal of Chemical Te
Chnology and Biote-chnolo
gy) *Volume 31, page 135 (1981), the reaction is carried out in a reaction system of boron trifluoride catalyst and DMSO solvent, and then IMF is purified through complex purification operations such as multi-stage extraction operations. Isolation and purification are underway.

In this way, with the conventional technology, when manufacturing }IMF, 1{
It requires a lot of effort to isolate and purify MP.

[Means to solve the problem]

The inventors of the present invention have intensively studied these problems regarding the purification and isolation of IMF, and have found that when a reaction is carried out using a substance in a supercritical state as a reaction solvent and an extractant, the raw material hexose is removed from the reaction system. It was discovered that IMF, which is hardly extracted and is a living substance, can be efficiently extracted into substances in a supercritical state, and since the extracted IMF only contains water as an impurity, it is possible to isolate it. It was found that purification was easy, and the present invention was completed.

That is, the present invention provides a method for producing IMF, which is characterized in that a substance in a supercritical state is present during the dehydration reaction of hexose in the presence of an acid catalyst.

In the present invention, a supercritical state refers to a state exceeding critical temperature (Tc) and critical pressure (Pc).

As a result of extensive studies regarding the method for producing IIMF, the present inventor added a substance in a supercritical state (supercritical fluid) that is chemically inert to the raw material hexose and the product IIMF to the reaction system. When hexose was heated in the presence of an acid catalyst, IIMF was produced by a dehydration reaction,
Furthermore, when the IIMF that was present in the reaction system was extracted by continuously introducing a supercritical fluid, it was found that 11 MP was extracted from the reaction system by the supercritical fluid.

At this time, almost no hexose used as a raw material was extracted. Since the supercritical fluid is a compound with a low boiling point when it returns to normal pressure, it was extremely easy to separate the IMF extracted from the reaction system and the supercritical fluid used for extraction. Also, H.M.
Water extracted together with P could also be easily separated from IMF by removing it under reduced pressure, resulting in highly pure IMF.

That is, the present invention uses a supercritical fluid in a reaction system and produces supercritical fluid or H? By using it as an extractant for IF, the purification process is easy and highly pure IIMF can be produced.

The supercritical fluid used in the present invention is not particularly limited as long as it can serve as a reaction solvent in a supercritical state;
For example, carbon dioxide, ethane, ethylene, propane, pentane, chlorofluorocarbon, etc. can be used. In particular, carbon dioxide is a stable and harmless inert gas, and is suitable because it easily forms a supercritical state even at relatively low temperatures (for example, carbon dioxide has Tc = 31°C, Pc = 75.3kg/cm ”G)
. Further, the ultra-Hip world fluid used in the present invention is water, DMSO
, DMF, alcohols, halogenated solvents, etc., may be used in a mixed state with solvents conventionally used in general chemical reactions. The mixing ratio may be any ratio.

The reaction catalyst used in the present invention may be any acidic catalyst, such as hydrochloric acid, sulfuric acid or a compound having a sulfonic acid group, phosphoric acid or a compound having a phosphoric acid group, boron trifluoride, aluminum chloride, etc. Lewis acid.

Further, a polymer compound having a sulfonic acid group such as a sulfonic acid type ion exchange resin is more preferably selected as the fixed catalyst. The amount of catalyst is influenced by the type of catalyst and reaction conditions, but it is usually 0.00% relative to the amount of hexose in the reaction system.
Selected from the range of 01 to 100% by weight. In the present invention, the reaction temperature may be 30 to 200'C as long as the reaction proceeds from hexose to IMF.
, more preferably from the range of 50 to 180°C. Further, the reaction pressure depends on the type of supercritical fluid and its physical properties, but is basically selected from a reaction pressure higher than the critical pressure of the substance used as a solvent.

The hexoses used as raw materials in the present invention are not particularly limited, such as aldohexoses and ketohexoses, but
Ketohexoses such as low fructose and L-sorbose are preferred, and sucrose, inulin, isomerized sugar solution, etc. containing these can also be used as raw materials.

Therefore, as the raw material used in the present invention, it is preferable to use isomerized sugar solution, sucrose, or fructose obtained by separating these by an appropriate method such as hydrolysis. Isomerization #
! In liquids or raw materials where glucose coexists, such as sucrose, fructose is preferentially dehydrated, so unreacted glucose is separated, and the separated glucose is subjected to reactions such as isomerization to transfer glucose to the liver. It becomes possible to convert Also, is hexose diluted with water to an appropriate concentration? ′? It can also be used as an I solution.

The reaction of the present invention can be carried out using, for example, supercritical chroma} SUPER2
This can be carried out using a device such as 00 (manufactured by JASCO Corporation). Figure 1 shows an outline of this device. The reaction of the present invention will be explained based on FIG. First, raw materials such as those shown in the following examples are placed in the reaction container 5, and the container is tightly stoppered. The reaction vessel is placed in a constant temperature bath whose temperature can be freely adjusted, and the supercritical fluid inlet and outlet lines are connected. Supercritical fluid (usually COz
) is introduced as follows. First, the cylinder 1 is cooled to about -5°C by passing through the cooler 2, and then,
It is pressurized to the set pressure by COX pump 3. Next, the supercritical fluid is introduced into the reaction vessel 5 while being maintained at a set temperature by passing through a preheating coil 4 and a constant temperature bath. The supercritical fluid and extract flowing out from the reaction vessel are
It enters the separation tank section and is returned from a pressurized state to a normal pressure state. At this time, normally used COt etc. becomes a gas and is exhausted.
Extracts that are difficult to vaporize are collected in the separation and collection section 6.

〔Effect of the invention〕

The method for producing IMP of the present invention uses a substance in a supercritical state (supercritical fluid) in the reaction system, heats and dehydrates hexose in the presence of an acid catalyst to produce IMP, and continuously produces supercritical fluid. IINF can be easily separated from the reaction system by introducing a fluid and extracting the IMF generated in the reaction system with a supercritical fluid, and furthermore, by removing water extracted together with IMF under reduced pressure, High purity IMF can be obtained. That is, the present invention uses a supercritical fluid in the reaction system and as an extractant for raw HMF, thereby providing a method for producing IIMF with an easy purification process and high purity.

〔Example〕

The present invention will be explained in more detail with reference to Examples below. However, the present invention is not limited to these examples.

Example 1 IMF was produced using a supercritical chromatograph SUPER 200 (manufactured by JASCO Corporation) (the outline of the device is shown in Figure 1). That is, 3.6 g of a 50% aqueous solution of fructose and 0.8 g of Amberlite IR-118}1 (3 meq/g as sulfonic acid group), which is an acid type sulfonic acid ion exchange resin, were placed in a 10 m7 supercritical reaction vessel 5. Prepared each and super-causal Cog under 200 kg/cm"G for 5m.
It was introduced into the reaction vessel 5 at a rate of 1/IIIin. Thereafter, when the temperature of the reaction vessel was gradually raised from room temperature to 90°C, HMF, which was alive with supercritical CO from about 80°C.
The outflow has started. Supercritical CO flowing out from the reaction vessel
, and the extract were stored in the separation and collection section 6. Separation and recovery section 6
When the outlet was returned to normal pressure, the CO2 was gasified and only the extract could be obtained. Supercritical CO at 90°C for 6 hours
．． As we continued to introduce supercritical C in the separation and recovery section,
The O2 extract was 1.3 g. The ultraviolet absorption spectrum of this product was measured, the absorbance at 284r++++ was determined, and the IMF content was determined from the absorbance of standard IMF (IMF content: 22% by weight). When water was removed from this extract under reduced pressure, 0.28 g of HMF with a purity of 94% by weight was obtained (yield 2% vs. fructose).

Example 2 The same procedure as in Example 1 was carried out, except that 3.4 g of a 50% aqueous solution of sucrose was used instead of 3.6 g of a 50% aqueous solution of fructose, and the introduction of supercritical C (h) was continued at 95°C for 10 hours. The operation was carried out to obtain 0.20 g of HMF with a purity of 9l% by weight (yield 14% vs. sucrose).

Example 3 Amberlite IR-118H, an acid type sulfonic acid ion exchange resin (3 meq/g as sulfonic acid group)
) The same operation as in Example 1 was performed except that 0.2 g of concentrated sulfuric acid was used instead of 0.8 g, and IMF with a purity of 93% by weight was obtained.
0.13g of (yield 9.5% vs. fructose) was obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the apparatus used in the method of the present invention. l: Cylinder 2: Cooler 3: Bump 4: Preheating coil 5: Reaction vessel 6: Separation and recovery section

Claims (1)

[Claims] 1. 5-hydroxymethyl- represented by the following general formula (I), which is characterized in that a substance in a supercritical state is present in the dehydration reaction of hexose in the presence of an acid catalyst.
Method for producing 2-furancarboxaldehyde. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) 2.Claim 1 that the substance in a supercritical state is carbon dioxide
Manufacturing method described.