JPS5953914B2 - Method for producing 5-chloromethylfurfural - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing 5-chloromethylfurfural.

More specifically, the present invention relates to the production of 5-chloromethylfurfural, which is characterized by using a catalytic amount of a surfactant when reacting 5-acetoxymethylfurfural with hydrochloric acid in the presence of an organic solvent inert to the reaction. It is the law.

The compound is useful as an intermediate for pharmaceuticals or agricultural chemicals, and can be converted into various furan derivatives.

A conventional method for producing 5-chloromethylfurfural is a method in which sucrose is treated with hydrochloric acid in the presence of carbon tetrachloride (J, Ch
Em, Soc, 667, 1944), but this method is not industrially practicable because it involves gelation during the reaction, complicates the operation, and has a low yield.

According to a report on a follow-up trial of this method, a large amount of humic substances are produced, making filtration and liquid separation after the reaction extremely difficult.

Therefore, as an industrial production method, a method has been proposed in which 5-acetoxymethylfurfural is reacted with hydrochloric acid to convert the acetoxymethyl group into a chloromethyl group (Japanese Patent Publication No. 4
5-39699).

According to this method, the desired product is said to be obtained in good yield by heating 5-acetoxymethylfurfural with hydrochloric acid. However, in this method, the heterogeneity of the reaction system increases as the reaction progresses, the reaction is slow, and the yield is not so good. Furthermore, as the temperature increases, the production of humic substances becomes more pronounced. For this reason, post-treatment after the reaction becomes difficult, and it is difficult to say that it is necessarily the optimal industrial production method.
The present inventors have conducted intensive studies on a method for producing 5-chloromethylfurfural from 5-acetoxymethylfurfural.
By using a catalytic amount of a surfactant when reacting acetoxymethylfurfural with hydrochloric acid, the reaction rate is extremely fast, gelation and resin formation accompanying the reaction progress are suppressed, and post-treatment is easy with no by-products. The inventors have newly discovered that the desired product can be obtained almost quantitatively, and after conducting various studies, they have completed the present invention.

5-acetoxymethylfurfural used in the present invention is
For example, it can be easily produced manually by formylating furfuryl acetate using the Wilsmeier reaction (Nikka Zasshi, Vol. 79, p. J137).

The hydrochloric acid used in carrying out the method of the present invention may be commercially available, and the amount used is not particularly limited as long as it is within the stoichiometric amount.

Usually, the purpose can be achieved by using 1 to 5 moles of 5-acetoxymethylfurfural per mole of 5-acetoxymethylfurfural.

Organic solvents used in the reaction include organic solvents that are inert to the reaction, such as aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene, and their halides, and fatty acids such as methylene chloride, chloroform, and carbon tetrachloride. Examples include group halogenated hydrocarbons and the like.

The reaction is carried out by mixing 5-acetoxymethylfurfural with hydrochloric acid in the presence of the aforementioned organic solvent and a catalytic amount of a surfactant. The hydrochloric acid to be used may be added in advance, or the hydrochloric acid to be consumed may be added continuously or intermittently as the reaction progresses. In this case, hydrogen chloride may be blown in in the presence of an appropriate amount of water. The desired 5-chloromethynoref'lefuranole can be obtained almost quantitatively from the solution after the reaction has been completed. The surfactants used in the present invention as interlayer transfer catalysts in a two-layer heterogeneous system include anionic surfactants (higher alkyl sulfonates, alkali metal salts of higher fatty acids, etc.), cationic surfactants (cetyl trimethyl Quaternary ammonium salts such as ammonium chloride and cetyldimethylbenzylammonium chloride), amphoteric surfactants (betaines such as lauryl dimethyl betaine, and amino acid derivatives such as sodium lauryl aminopropionate) are used.

Among these, anionic agents and amphoteric agents are preferred, followed by cationic agents. More preferably, when using a mixed activator consisting of approximately equal amounts of an anionic agent and a cationic agent, the system is less likely to become micelle-like and turn into a resin.
The reaction proceeds smoothly and effectively, and post-reaction treatment is easy.

A preferred combination is, for example, one part of sodium laurylbenzenesulfonate in the form of a sulfonate as an anionic agent and one part of cetyltrimethylammonium chloride in the form of a quaternary ammonium salt as a cationic agent.

The amount of surfactant used is 1/1000 to 1/10 mol, preferably 1/200 to 1/50 mol, per 1 mol of 5-acetoxymethylfurfural.

The reaction temperature can be heated to promote the reaction, but since the reaction is rapid, a temperature of 100°C or lower, preferably in the range of about 0°C to about 60°C, is suitable.

Under such conditions, the reaction is usually completed in 10 minutes to 10 hours. ) The progress of the reaction can be determined by gas chromatography or other conventional methods.

The desired 5-chloromethylfurfural is obtained in high yield and purity from the liquid after the reaction. If necessary, it is also possible to purify by chromatography or other conventional methods. As detailed above, the production of 5-chloromethylfurfural by the method of the present invention is extremely advantageous industrially.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 5-acetoxymethylfurfural 10t1 Two types of surfactants Sodium laurylbenzenesulfonate 1027
V1 Cetyltrimethylammonium chloride 9377
V was placed in a three-necked flask equipped with a condenser and a stirrer kept at 0 to 5°C. 40 liters of toluene was added, and the mixture was stirred and suspended.

Approximately 6 mt of 35% hydrochloric acid was slowly added dropwise at 0 to 5°C over approximately 30 minutes with stirring, and then a slightly excess amount of hydrogen chloride (approximately 7 r) was slowly added over 1 hour while stirring at the same temperature. After blowing, the temperature was raised to about 20° C. over a further 1 hour, and then kept warm and stirred for about 4 hours. The reaction solution was diluted with a small amount of water, decolorized with activated carbon (approximately 0.4 f), passed through celite while washing with toluene, and the toluene layer was washed with saturated brine, dried, and concentrated to give about 8.2
A crude product (purity 999% theoretical 8.6f), 5-chloromethylfurfural, was obtained. Example 2 10 t of 5-acetoxymethylfurfural, 207 ml of sodium laurylbenzenesulfonate as surfactant
I! The mixture was placed in a three-bottle flask equipped with a condenser and a stirrer kept at a temperature of 0 to 5°C, and 40f of toluene was added to stir and suspend.

Approximately 6W1t of 35% hydrochloric acid was slowly added dropwise at 0 to 5°C over approximately 30 minutes with stirring, and then a slightly excess amount of hydrogen chloride (approximately 7F) was slowly added over 1 hour while stirring at the same temperature. Blow in and heat to approximately 20°C for another hour.
After that, the mixture was kept warm for about 4 hours and stirred.
The reaction solution was diluted with a small amount of water, decolorized with activated carbon, passed through Celite while washing with toluene, and the toluene layer was neutralized with saturated brine, dried, and concentrated to give about 7.6r of crude product, 5- Chloromethylfurfural (purity 97%) was obtained. Example 3 Tetra n-butylammonium bromide 192 as 5-acetoxymethylfurfural 10t6 surfactant
7V was charged into a three-bottle flask equipped with a cooling tube and a stirrer kept at 0 to 5°C. 40V of toluene was added and stirred to suspend.

Approximately 6 m2 of 35% hydrochloric acid was slowly added dropwise and stirred at 0 to 5°C over a period of about 30 minutes from the dropwise loading, and then a slightly excess amount of hydrogen chloride was slowly blown in over an hour while stirring at the same temperature, and then Raise the temperature to about 20℃ over 1 hour,
Thereafter, the mixture was kept warm and stirred for about 5 hours. The reaction solution was diluted with a small amount of water, decolorized with activated carbon, passed through Celite while washing with toluene, and the toluene layer was neutralized with saturated brine, dried, and concentrated to give about 7.3 tons of crude product, 5- Chloromethylfurfural (purity 95%) was obtained.

Claims (1)

[Claims] 1. A method for producing 5-chloromethylfurfural, which comprises using a catalytic amount of a surfactant in the presence of an organic solvent inert to the reaction when reacting 5-acetoxymethylfurfural with hydrochloric acid.