JPS6160639A - Alpha-metylbenzylideneaminoacetonitrile and its preparation - Google Patents

Abstract

NEW MATERIAL:alpha-Methylbenzylideneaminoacetonitrile of formula. USE:Synthetic raw material and synthetic intermediate of organic compounds such as alpha-amino acids. PREPARATION:The objective compound of formula can be preparated by reacting glycinonitrile with acetophynone in the presence of an acid catalyst (e.g. p-toluenesulfonic acid) in a solvent forming an azeotropic mixture with water (e.g. benzene, toluene, etc.) at 20-150 deg.C for 1-30hr, and removing the water produced by the reaction by conventional azeotropic distillation method. The reaction is carried out by using either of glycinonitrile or acetophenone, preferably acetophenone in excess.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a new compound α-methylbenzylidene aminoacetonitrile and a method for producing the same.

The α-methylbenzylidene aminoacetonitrile of the present invention can be used as a raw material or intermediate for the synthesis of various organic compounds including various α-amino acids by reacting with organic halides such as benzyl chloride or aldehydes such as formaldehyde. In principle, it can be synthesized from glycinonitrile and 7cetophenone, but this may be because the raw material glycinonitrile is a substance with low stability.
I have never seen an attempt to synthesize this.

As a slightly similar example, a recent example of the synthesis of a thick base of glycinonitrile using benzophenone as a ketone has been shown.
(Tetrahedron)
LeLt'ers No, 49, P, 4E
i25).

Means for Solving Problems The present inventors have succeeded in obtaining α-methylbenzylidene aminoacetonitrile, a novel compound, in high yield by conducting the reaction between glycinonitrile and acetophenone advantageously.

That is, according to the present invention, α-methylbenzylidene aminoacetonitrile represented by the following formula is provided. Furthermore, as a method for producing the same, there is provided a method characterized in that glycinonitrile is reacted with 7cetophenone in the presence of an acid catalyst, and water produced by the reaction is removed by known co-distillation.

According to the method of the present invention, acetophenone is dissolved in a solvent such as benzene or toluene together with water, an acid catalyst is added thereto, and glycinonitrile is added directly at once or added dropwise over time.

The water produced by the reaction is distilled out of the system as an azeotropic component,
Complete the reaction.

Generally, the condensation reaction between aromatic ketones and 7mino is slow, so a catalyst is used. The catalyst used is protonic acid, BF3
- Examples include etherate, zinc chloride, etc. (C
Comprehensive OrganicChem
istry, Vol, 2, P, 387 (19
79)) We investigated various catalysts for this reaction and found that in addition to the above catalysts, activated alumina, silica alumina, silica magnesia, silica, H type Y-zeolite, rare earth exchanged Y-zeolite, H type mordenite, butyric clay, hydrogen It was discovered that solid acid catalysts such as type acid clay, metal-exchanged acid clay, activated clay, and acidic ion exchange resins, and organic acids such as acetic acid, propionic acid, methanesulfonic acid, benzenesulfonic acid, and para-toluenesulfonic acid are effective. Ta.

Glycinonitrile, one of the raw materials for this reaction, itself has low stability, so if the reaction conditions and catalyst are not selected, decomposition reactions will occur simultaneously and the yield of thick base will not increase. Among the catalyst groups mentioned above, Schiff is especially important! ! ! i! !
Catalysts with high reaction yields for i are limited to those listed below.

Activated alumina, HIY-zeolite, H-type X-zeolite, rare earth-exchanged Y-zeolite, acid clay, hydrogen-type acid clay, metal-exchanged acid clay, activated clay, para-toluenesulfonic acid.

Among these, solid catalysts have advantages such as continuous reaction, ease of post-treatment, and less waste.

Among organic acid catalysts, para-toluenesulfonic acid showed a particularly excellent effect.

In the case of a solid acid, the amount of catalyst used is the heavy J of glycinonitrile.
If 11 is 1, then 0.1 to 2, preferably 0.5 to 1
．． It is 0.

The reaction temperature is the azeotropic temperature of the solvent and water, so it is determined by the type of solvent and the reaction pressure, but it is usually 20 to 150°C.The reaction pressure is usually normal pressure, but the reaction temperature can be adjusted. It does not matter whether the pressure is reduced or increased in order to
゛Reaction time is 1 to 30 hours.

Regarding the ratio of glycinonitrile and 7cetophenone used, using an excess of either one is advantageous in terms of reaction rate.

It is advantageous to use an excess of acetophenone from both stability and recovery standpoints, and the ratio is naturally limited in terms of by-product generation and recovery, and a suitable molar ratio is 1:i, oi to 2.0. It is.

The solvent is a solvent that is conjugated with water, has a low solubility in water, and has an appropriate azeotropic temperature. Examples include benzene, toluene, cyclohexane, and ethylene dichloride.

Water can be removed by a conventional method, such as by cooling and condensing the azeotropic vapor outside the system, allowing it to stand, and returning only the solvent to the system.

The reaction product, monoMα-methylbenzylidene and acetonitrile, was removed from the reaction path by distilling off the solvent from the liquid.
It can be isolated from unreacted azeotropic substances such as 7-cetophenone by distillation under reduced pressure.

2. Examples Examples will be described below.

In the example, 800 m of benzene was placed in a 1500 m separable flask equipped with a moisture regulator with a flow cooler! Add 1 h, dissolve 128.7 g (1.05 mol) of acetophenone,
Add 0.25g of balatoluenesulfone m1 hydrate,
Heat in an oil bath at 100℃.

Under stirring and reflux, 90% glycinonitrile aqueous solution 54.5
g (0,875 mol) was added dropwise over 20 minutes. The reaction was carried out while separating water using a water meter. After 6 hours, the reaction solution was analyzed by gas chromatography, and it was found that 131.5 g of α-methylbenzylidene aminoacetonitrile (0
, 831 mol) was produced. Yield 85%.

Benzene was distilled off under reduced pressure from the reaction solution, and then distilled under reduced pressure under a nitrogen cloud to obtain a fraction having a temperature of 133° C. to 134° C. at 3+s+s Hg. This pale yellow crystal had the following physical properties.

Melting point 44-46°C Elemental analysis value (CH, H) 0% 6% N% Actual value 73.88 6.34 17.47 Calculated value 75.92 8.37 17.71'H
The magnetic co-1B spectrum (CD0 pattern 3 in solvent) 4.37
ppm (2H)2.30
(3H)? , 25-7.90 (5H) Example 2 7cetophenone Ei in 30ml of ethylene dichloride,
Add 4g (53.0 mmol) and 20hg of paratoluenesulfone monohydrate, and add 2g of glycinonitrile under reflux.
．． 0 g (35.3 mmol) was added, and the reaction was carried out while removing water using a water meter. After 2 hours, the reaction solution was analyzed by gas chromatography, and it was found that α-methylbenzylidene aminoacetonitrile was produced in a yield of 83.8%.

Example 3 Ethylene dichloride 30mJi! acetophenone 3
．． 2. (28.5 mmol), glycinonitrile 1
．． Og (17.7 mmol) was dissolved, 1.0 g of acid clay (Mizusawa Chemical Department) was added as a catalyst, and the mixture was reacted under reflux while water was separated using a water meter. Analysis of the reaction solution after 2 hours revealed that α-methylbenzylideneaminoacetonitrile had been produced in a yield of 75.4%.

Examples 4 to 10 The reaction was carried out in the same manner as in Example 3, except that the catalyst was changed to one shown in Table 1. The results are summarized in Table 1.

Table 1

[Brief explanation of drawings]

FIGS. 1 and 2 show the mass spectrum and magnetic resonance spectrum of Mα-methylbenzylidenethiaminoacetonitrile.

Claims (2)

[Claims] (1) α-methylbenzylidene aminoacetonitrile represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (2) A method for producing α-methylbenzylidene aminoacetonitrile, which comprises reacting glycinonitrile with acetophenone in the presence of an acid catalyst and removing water produced by the reaction by known azeotropic distillation.