JPH0713068B2 - Method for producing furfuryl alcohol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention provides a compound of formula (I) (In the formula, R represents a hydrogen atom or a methyl group) The present invention relates to a method for producing furfuryl alcohols.

<Prior Art> The furfuryl alcohols represented by the above general formula (I) are useful intermediates for agricultural chemicals, pharmaceuticals, perfumes and the like.

Conventionally, as a method of obtaining an alcohol by a reaction of a carbonyl compound and a propargyl halide, (a) a Grignard reaction method, (b) a Rifomasky reaction method, (c) an organolithium compound method and the like are well known. There is.

<Problems to be Solved by the Invention> However, all of these methods require water-prohibiting conditions which are extremely disadvantageous industrially, and also involve a very large reaction heat, and particularly, in (a) and (b). The method has a problem that it is extremely difficult to carry out on an industrial scale, such as passing through an intermediate product having a rapid heat generation and ignitability.

From the above, the present inventors have improved the above-mentioned drawbacks,
As a result of various studies for producing the furfuryl alcohols represented by the above general formula (I) industrially, furfurals and prappargyl halides were first combined with zinc, an inorganic ammonium salt and an organic quaternary ammonium salt system. It was found that the desired furfuryl alcohols can be obtained in a good yield in a short time by reacting in water or a water-organic solvent mixed solvent in the presence of a surfactant (Japanese Patent Application No. 61-
177119), and as a result of further examination of this method,
The present invention has been completed by finding that the efficiency is further improved by carrying out the reaction by a specific reaction method.

<Means for Solving Problems> The present invention provides a compound represented by the general formula (II): (In the formula, R has the same meaning as described above) The furfural represented by the formula: The present invention provides a method for producing furfuryl alcohols represented by the general formula (I), characterized in that the reaction is carried out while sequentially adding propargyl halide.

Furfural or 5-methylfurfural is used as the raw material furfural in the present invention, and propargyl chloride is used as the pupargyl halide.
Propargyl bromide is used.

In the present invention, the amount of zinc used is usually in the range of 1 to 5 times the mol of the raw material furfural.

As the inorganic ammonium salt used in this reaction, ammonium chloride and ammonium bromide are preferable, and the amount thereof is usually 0.01 to 1 times the weight of the reaction solution described later. Of course, the reaction proceeds even if the amount exceeds 1 time, but the slurry concentration increases, which is industrially disadvantageous. Although the reaction proceeds even if the amount is less than 0.05 times the weight, it takes a long time to complete the reaction, which is industrially disadvantageous.

Further, as the organic quaternary ammonium salt-based surfactant, an organic quaternary ammonium salt known as a surfactant is used, and particularly preferred are tetraethylammonium bromide, tetraethylammonium chloride and tetraethylammonium bromide. Propylammonium, tetrapropylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide, tetrabenzylammonium bromide, tetrabentylammonium chloride, benzyltriethylammonium chloride, benzyltripropylammonium chloride, odor And dodecyltrimethylammonium chloride and cetyltrimethylammonium chloride.

The amount of such organic quaternary ammonium salt used is preferably in the range of 0.005 to 1 times the molar amount of the raw material furfural. Of course, the reaction proceeds even if the amount exceeds 1 time, but the raw material cost increases, which is uneconomical.

The reaction is carried out in a water solvent or a water-organic solvent mixed system. The organic solvent is selected from aliphatic or aromatic hydrocarbons, ethers and amines, preferably n-hexane, toluene, xylene, tetrahydrofuran, diethyl ether and pyridine. The amount of the solvent used is usually 1 to 50 times the weight of the raw material furfural and 0 to 30 times the weight of the organic solvent, but it is not particularly limited.

In the reaction, the furfural represented by the general formula (II) is added to water or a water-organic solvent mixed solvent in the presence of zinc, an inorganic ammonium salt and an organic ammonium salt,
It is important to do so with successive additions of propargyl halide.

The addition method may be continuous or intermittent. The amount of propargyl halide used here is usually 1 to 5 times the mol of the raw material furfural, and
The addition is usually performed in the range of 30 minutes to 5 hours, but the addition time is not particularly limited.

However, addition in a short time leads to a decrease in yield and is generally disadvantageous.

The reaction temperature is generally selected in the range of 0 to 100 ° C, preferably 5 to 80 ° C.

The progress of the reaction is monitored by instrumental analysis such as gas chromatography, and the reaction ends when all the raw material furfurals have disappeared. The furfuryl alcohols are collected from the reaction solution by, for example, separating the organic layer and then distilling the organic layer.

<Effects of the Invention> Thus, according to the method of the present invention, the desired furfuryl alcohols represented by the general formula (I) can be industrially easily obtained in a short time.

<Examples> Hereinafter, the present invention will be described with reference to Examples.

Example 1 In a flask, 44 g of 5-methylfurfural, 52.3 g of zinc powder,
Tetrabutylammonium bromide 26g, ammonium chloride 8
After charging 8 g, 88 g of toluene and 79.28 g of water, while maintaining the temperature at 35 ± 2 ° C. with stirring, provalgyl chloride 59.6
g was added dropwise over 1 hour. After the dripping is completed, 2 at the same temperature
Held for hours.

After the reaction was completed, the reaction solution was separated, and the organic layer was rectified under reduced pressure to obtain a fraction of 2- (1-hydroxy-3-butynyl) -5-methylfuran (56.6 g, content 99.6%). (Yield 93.8
%) Comparative Example 1 The reaction and post-treatment were performed in the same manner as in Example 1 except that propargyl chloride was added instantaneously, and 49.1 g of a fraction of 2- (1-hydroxy-3-butynyl) -5-methylfuran was obtained.
(Content 99.5%) was obtained (yield 81.3%).

Example 2 In a flask, 44 g of 5-methylfurfural, 47.1 g of zinc powder,
After charging tetrabenchlammonium chloride 28g, ammonium chloride 66g, toluene 66g and water 814.8g, propargyl bromide 6 while stirring and maintaining at 40 ± 2 ° C
2.8 g was added dropwise over 1 hour. After the dropping was completed, the temperature was maintained for 2 hours at the same temperature.

After completion of the reaction, the reaction solution was separated, and the organic layer was rectified under reduced pressure to obtain a fraction of 2- (1-hydroxy-3-butynyl) -5-methylfuran 54.9 g (content 99.7%). (Yield 91.1
%).

Comparative Example 2 The same reaction and post-treatment as in Example 2 were carried out except that propargyl bromide was charged into the flask before the reaction was started.
47.1 g (content 99.5%) of a fraction of 2- (1-hydroxy-3-butynyl) -5-methylfuran was obtained (yield 78.0).
%).

Example 3 Example 1 was repeated except that an equimolar amount of furfural was used instead of 5-methylfurfural, cetyltrimethylammonium chloride was used instead of tetrabutylammonium bromide, and tetrahydrofuran was used instead of toluene, respectively. Perform the same reaction and post-treatment, and
Fraction of (1-hydroxy-3-butynyl) -furan 50.1
g (content 99.4%) was obtained (yield 91.4%).

Example 4 45.5 g of ammonium bromide was used instead of ammonium chloride, and tri-n-butylamine 44 was used instead of toluene.
The same reaction and post-treatment as in Example 1 were carried out except that g was used to give 2- (1-hydroxy-3-butynyl) -5-
54.5 g (content 99.7%) of methylfuran fraction was obtained (yield 9
0.5%).

Claims (3)

[Claims] 1. A general formula (In the formula, R represents a hydrogen atom or a methyl group), and furfurals represented by the formula: in the presence of zinc, an inorganic ammonium salt and an organic quaternary ammonium salt surfactant in water or a water-organic solvent mixed solvent. A general formula characterized by reacting while sequentially adding propargyl halide (In the formula, R has the same meaning as described above.) A method for producing furfuryl alcohols. 2. The method according to claim 1, wherein the organic solvent is at least one selected from aliphatic hydrocarbons, aromatic hydrocarbons, ethers and amines. 3. An organic quaternary ammonium salt surfactant is tetraethylammonium bromide, tetraethylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraiodide. Butylammonium, tetrapentylammonium bromide, tetrapentylammonium chloride, benzyltriethylammonium chloride, benzyltripropylammonium chloride, dodecyltrimethylammonium bromide or cetyltrimethylammonium chloride.
The manufacturing method according to item.