JPH11130739A - Production of isovanillamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain the subject high purity compound without using mercury at all by reacting isovanillin with ammonia in the presence of an alkali hydroxide. SOLUTION: This compound is obtained by reacting (A) isovanillin with (B) ammonia in the presence of (C) an alkali hydroxide (e.g. sodium hydroxide) and, if necessary, (D) a reducting catalyst (e.g. Raney nickel), preferably in a solvent (e.g. water) and preferably at 30-45 deg.C more preferably 35-40 deg.C. The component B is preferably used at 3-6 mol more preferably 4.5-5.5 mol based on one mol component A. The component C is preferably used at 0.5-1.2 mol based on one mol component A. The component D is preferably used at 10-40 pts.wt. based on 100 pts.wt. component A. Alernatively, the component A and the component B may be subjected to catalytic reduction with hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing isovanylamine. More specifically, the present invention relates to a method for producing isovanylamine, which is useful as a raw material for medicines and agricultural chemicals.

[0002]

2. Description of the Related Art Isovanylamine is a useful compound as a raw material for medicines and agricultural chemicals. Conventionally, isovanylamine is produced by reacting isovanillin with hydroxyamine to form an oxime form, and then reducing it with sodium amalgam. Zhonghua YaoxueZazhi 1992, 44 (1), p.51-6
0).

[0003] However, such a method requires sodium amalgam containing mercury for reduction. Therefore, development of a method for producing isovanylamine without using mercury has been awaited from an environmental viewpoint.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and provides a method capable of efficiently producing isovanylamine having high purity without using any mercury. With the goal.

[0005]

That is, the present invention provides:
(1) A method for producing isovanylamine, which comprises reacting isovanillin with ammonia in the presence of an alkali hydroxide, and (2) the above-mentioned (1), wherein isovanillin and ammonia are reacted in the presence of a reduction catalyst. And a process for producing isovanylamine.

[0006]

According to the production method of the present invention, isovanylamine can be produced by reacting isovanillin with ammonia in the presence of an alkali hydroxide.

[0007] The reaction between isovanillin and ammonia can usually be carried out in a solvent. As the solvent,
For example, water, methanol and the like can be mentioned. Among them, water is preferable from the viewpoint of safety against fires and the like.

When water is used as the solvent, for example, the reaction between isovanillin and ammonia can be carried out using aqueous ammonia or an aqueous ammonia solution obtained by previously dissolving ammonia in water. In this case, the concentration of ammonia in the aqueous ammonia solution is not particularly limited, but may be generally about 5 to 20%.

The amount of the ammonia used is preferably at least 3 mol, especially at least 4.5 mol, and more preferably at least 4.5 mol, per 1 mol of isovanillin, from the viewpoint of accelerating the reaction and suppressing the formation of by-products. When a large amount is used, there is no advantage of using such a large amount, and it becomes uneconomical. Therefore, the amount is preferably 6 mol or less, especially 5.5 mol or less.

In the present invention, there is one major feature in the presence of alkali hydroxide when isovanillin and ammonia are reacted. In the case where alkali hydroxide is present, isovanylamine is converted to isovanylamine. It can be obtained quickly and in high yield.

The alkali hydroxide includes, for example, sodium hydroxide, potassium hydroxide and the like. Of these, sodium hydroxide is
It can be suitably used in the present invention.

The amount of the alkali hydroxide used is preferably 0.5 mol or more per 1 mol of isovanillin to sufficiently dissolve the isobanin and the reaction product. To generate
It is preferable that the content be 1.2 mol or less.

The above-mentioned alkali hydroxide is previously added to and dissolved in an ammonia solution, and then, by adding isovanillin thereto, ammonia and isovanillin can be reacted.

In the reaction, it is preferable to use a reduction catalyst. Examples of such a reduction catalyst include Raney nickel, Raney cobalt, palladium carbon, platinum carbon and the like. Among these reduction catalysts, Raney nickel is inexpensive and can be suitably used in the present invention. The amount of the reduction catalyst used is preferably 10 parts by weight or more from the viewpoint of sufficiently increasing the reaction rate with respect to 100 parts by weight of isovanillin on a wet weight basis, and 40 parts by weight from the viewpoint of the filterability of the catalyst. Parts or less. The reduction catalyst may be added to the ammonia solution before adding the isovanillin to the ammonia solution.

The reaction temperature at the time of reacting ammonia and isovanillin is preferably 30 ° C. or higher from the viewpoint of increasing the reaction rate, and is higher than 45 ° C. Is preferred. A particularly preferred reaction temperature is 35 to 40 ° C.

Since the reaction between ammonia and isovanillin is a reduction reaction, it can be catalytically reduced with hydrogen. In this case, the reaction atmosphere is replaced with hydrogen gas,
Hydrogen gas pressure from atmospheric pressure 10 kg / cm ² may be (gauge pressure, hereinafter the same), inter alia 3-5 kg / cm ² about the. The reaction of ammonia with isovanillin, for example,
It can be confirmed that the absorption of hydrogen has been completed.

After completion of the reaction, the reaction solution is preferably filtered to separate the catalyst and the like. In addition, when Raney nickel is used, nickel elutes in the filtrate,
It is preferable to add sodium dimethyldithiocarbamate to the reaction solution. Thus, when sodium dimethyldithiocarbamate is added to the reaction solution, white isovanylamine can be obtained.

The amount of sodium dimethyldithiocarbamate used depends on the amount of nickel ions eluted, but when nickel ions are present in the reaction solution at about 1000 ppm, usually 100 parts by weight of isovanillin is used.
It is preferably about 0.1 to 2 parts by weight. that time,
The addition of sodium borohydride can prevent the resulting isovanylamine crystals from being colored. The addition amount of sodium borohydride may be about 1 to 2 parts by weight based on 100 parts by weight of isovanillin.

Next, the precipitate formed by the addition of sodium dimethyldithiocarbamate is filtered. In addition,
At the time of filtration, a filter aid such as celite may be added.

Hydrochloric acid is added to the filtrate to adjust the pH to 9 to 10.5.
By adjusting the degree to, preferably, 9.8 ± 0.3, isovanylamine can be crystallized as white crystals.

Thus, isovanylamine can be prepared in a short time,
Moreover, it can be obtained in a high yield, and the obtained isovanylamine can be suitably used as a raw material for medicines, agricultural chemicals and the like.

[0022]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to only these examples.

Example 1 40.5 g (1 mol) of sodium hydroxide, 340 g of a 25% aqueous ammonia solution and 152 g (1 mol) of isovanillin were added to and dissolved in 500 g of water.

Next, 46 g of Raney nickel was added to this solution.
Was added and the mixture was reduced under a hydrogen gas pressure of 5 kg / cm ² , and hydrogen absorption was completed in 3 hours.

Next, 440 g of water was added to the obtained reaction solution, followed by filtration and washing, followed by sodium borohydride 2
g, 3 ml of a 40% aqueous solution of sodium dimethyldithiocarbamate and 30 g of Celite were added, and the mixture was filtered. Concentrated hydrochloric acid was added dropwise to the filtrate to adjust the pH to 9.8, and the precipitated crystals were collected by filtration, washed and dried to obtain 134.7 g of white isovanylamine (purity 99.8%, yield 88%). ). The melting point of the obtained isovanylamine is from 159 to
163 ° C. IR (KBr cm ^-1 ): 325
6, 1592, 1494, 1420, 1286, 122
0

Example 2 13.2 g (0.33 g) of sodium hydroxide was added to 164 g of water.
Mol), 50 g (0.33 mol) of isovanillin and 2
100 g of a 5% aqueous ammonia solution was added and dissolved.

Next, Raney nickel 15.
When 4 g was added and reduced at a hydrogen gas pressure of 3 kg / cm ² , hydrogen absorption was completed in 5 hours.

Next, 156 ml of water was added to the obtained reaction solution, followed by filtration and washing. Then, 0.8 g of sodium borohydride, 1 ml of a 40% aqueous solution of sodium dimethyldithiocarbamate and 10 g of celite were added, and the mixture was filtered. . Concentrated hydrochloric acid was added dropwise to the filtrate to adjust the pH to 9.87,
The precipitated crystals were collected by filtration, washed and dried to obtain 44.3 g of white isovanylamine (purity: 99.9).
%, Yield 87.6%). The melting point of the obtained isovanylamine was 159 to 163 ° C.

Comparative Example 1 To 500 ml of water, 152 g (1 mol) of isovanillin and 340 g of a 25% aqueous ammonia solution were added and stirred. Next, 46 g of Raney nickel was added to this solution, and reduced under a hydrogen gas pressure of 5 kg / cm ² . After 9 hours, the reaction was terminated because hydrogen absorption became slow.

Next, 40.5 g (1 mol) of sodium hydroxide was added to the reaction solution in which isovanylamine was precipitated.
g and added to dissolve, and the catalyst was filtered and washed.

Concentrated hydrochloric acid was added dropwise to the obtained filtrate to adjust the pH to 9.8, and the precipitated crystals were filtered, washed and dried to obtain 114.9 g of dark greenish gray isovanylamine (purity: 97). 0.7%, yield 75%). The melting point of the obtained isovanylamine was 158 to 159 ° C.

From the above results, it can be seen that according to the methods of Examples 1 and 2, isovanylamine having high purity can be efficiently obtained without using any mercury.

According to the methods of Examples 1 and 2, as compared with Comparative Example 1, the addition of sodium hydroxide to the aqueous ammonia solution makes it possible to obtain isovanylamine with high purity and high yield. You can see that you can do it.

[0034]

According to the production method of the present invention, an excellent effect is obtained that isovanylamine having high purity can be produced efficiently without using any mercury.

Claims (2)

[Claims] 1. A method for producing isovanylamine, comprising reacting isovanillin with ammonia in the presence of an alkali hydroxide. 2. The process for producing isovanylamine according to claim 1, wherein isovanillin and ammonia are reacted in the presence of a reduction catalyst.