JP3310414B2 - Method for producing monoallyl hydrazine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing monoallyl hydrazine which is useful as a raw material for agricultural chemicals and pharmaceuticals and as an intermediate for synthetic chemistry, and more particularly to monoallyl hydrazine containing substantially no hydrazine. And a method for producing the same.

[0002]

2. Description of the Related Art As a method for producing allyl hydrazine, a method of reacting allyl chloride and hydrated hydrazine in ethanol and purifying with hydrochloride [Chem. B
er. 47 (1914) 3031] is known,
In this method, the yield of monoallyl hydrazine is low and the method is not practical.

Further, a method has been proposed in which a hydrated hydrazine is derivatized to an alkylidene-acyl-hydrazine, followed by allylation and then hydrolysis (Japanese Patent Application Laid-Open No. 2-67268). Is obtained, but the process is too complicated to be an industrial production method.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing monoallyl hydrazine by allylating hydrazine with allyl chloride to sufficiently suppress by-products of higher allyl hydrazine and to reduce selectivity. It is another object of the present invention to provide a method for producing monoallyl hydrazine well, and a method for efficiently separating a mixture of monoallyl hydrazine and hydrazine and producing a high-purity monoallyl hydrazine substantially containing no hydrazine.

[0005]

According to the present invention, in separating monoallylhydrazine and hydrazine from a mixture thereof, the mixture is treated with an aqueous alkali solution, characterized in that the mixture is treated with a substantially hydrazine-free monohydrazine. A method for producing allyl hydrazine is provided.

In the present invention, the above monoallylhydra
The mixture of gin and hydrazine is
Reacting hydrazine with allyl chloride in liquid
Can be obtained by

That is, according to the present invention, an excess of hydrazine
React hydrazine with allyl chloride in aqueous solution
By this, by-products of higher allylic hydrazine are suppressed,
Monoarylhydrazine can be produced with high selectivity
Can be mixed with hydrazine
Obtained in the form of objects. Therefore, this mixture is
By treating with a solution, substantially no hydrazine is contained.
Monoallyl hydrazine can be obtained.

[0008]

It is known that the reaction between hydrazine and allyl chloride proceeds sequentially as shown below.

Embedded image (1) NH ₂ NH ₂ + RCl−> RNHNH ₂ + HCl (2) RNHNH ₂ + RCl−> RNHNH + HCl−> R ₂ NHNH ₂ + HCl (3) RNNHHR + RCl−> R ₂ NHNHR + HCl R is an allyl group (CH ₂ ＣＨCH—CH ₂ —).

The present inventors have conducted intensive studies on the reaction between hydrazine and allyl chloride. As a result, by conducting this reaction in an excess aqueous hydrazine solution, the reaction of the above formula (1) It was found that the selectivity was improved (see Example 1 described later).

In this allylation reaction, it is natural that a part of the excess hydrazine aqueous solution becomes a reactant, but most of the rest becomes a reaction medium excellent in the substitution reaction.
It is recognized that by-products of higher-order allylated hydrazine represented by the formulas (2) and (3) can be suppressed, and the selectivity to monoallylhydrazine can be increased.

Performing the substitution reaction with allyl chloride in an excess aqueous solution of hydrazine is also effective to carry out the reaction at a relatively low temperature, for example, 50 ° C. or less. The reaction suppresses the by-product of higher-order allylated hydrazine, and makes it possible to increase the selectivity to monoallyl hydrazine.

The crude monoallyl hydrazine separated from the above reaction mixture contains accompanying hydrazine, and purification is indispensable. After examining various methods,
It has been found that a highly concentrated aqueous alkali solution is a highly selective extractant of hydrazine only.

In the present invention, a mixture of monoallylhydrazine and hydrazine is subjected to an extraction operation with a high-concentration aqueous alkali solution, and hydrazine is extracted into an aqueous alkali solution. Can be manufactured.

The aqueous alkali solution of hydrazine can be reused in the reaction with allyl chloride by neutralizing the alkali.

[0015]

The allyl chloride used in the present invention is
Any substance having ordinary purity may be used, and one containing no polymer of allyl chloride is particularly preferable.

The aqueous solution of hydrazine used in the same manner is a commercially available hydrated hydrazine (for example, 60% hydrazine, 80% hydrazine).
% Product and 100% product) and the hydrazine concentration is not particularly limited.

In the present invention, since an aqueous hydrazine solution is also used as a reaction medium, an excess aqueous hydrazine solution is always used. Normally, hydrochloric acid generated in the reaction is neutralized with caustic soda, the salt is separated, and the aqueous solution of hydrazine containing salt of the mother liquor is reused.

In the present invention, the neutral salt contained in the hydrazine aqueous solution to be reused does not affect the reaction at all, and can be used in the same manner as a fresh hydrazine aqueous solution.

In the present invention, the reaction between hydrazine and allyl chloride is preferably carried out by a dropping method (batch operation) while dripping allyl chloride under rapid stirring of the hydrazine aqueous solution. It is important that the allyl chloride be present in the continuous phase and be dispersed in the continuous phase as fine droplets.

In the reaction of the present invention, an embodiment in which allyl chloride in a gas phase is absorbed in an aqueous hydrazine solution is also one of the preferable embodiments.

In a state in which a continuous phase of allyl chloride exists and forms two phases with an aqueous hydrazine solution, non-selective allylation reaction in the allyl chloride phase is involved, and consequently higher allylated hydrazine is formed. There is a disadvantage that the selectivity becomes large.

As already pointed out, the reaction temperature has a great influence on the selectivity for monoallylhydrazine. Preferred reaction temperatures are from 50 to 0 ° C, particularly preferably from 40 to 20 ° C. At a reaction temperature higher than the above temperature, the selectivity to monoallyl hydrazine decreases, and when it is lower than the above reaction temperature, a long time is required for the reaction, which is industrially disadvantageous.

The amount of the aqueous hydrazine solution used for the reaction is
At the end of the reaction, it is necessary to satisfy the molar ratio of hydrazine / allyl chloride of 6 or more in the total amount used. As described above, in a reaction in a batch operation of dropping and dispersing allyl chloride in an aqueous hydrazine solution, in practice, at a certain point in time during the progress of the reaction, the molar ratio of hydrazine / allyl chloride present in the system is extremely large. value,
For example, the molar ratio is 100 or more.

The dropping rate [mol / Hr] of allyl chloride per unit volume [L] of the aqueous hydrazine solution is affected by the cooling rate of the system. However, when ordinary equipment is used, 2.5 [mol / Hr] is used. L · Hr] or less. When the dropping rate is 3.5 [mol / L · Hr] or more, the dispersion of allyl chloride in the hydrazine aqueous solution becomes insufficient, and the by-products are increased, which is not preferable.

When the reaction is carried out under the above conditions, the selectivity to monoallyl hydrazine becomes 80 mol% or more, and the by-product of higher allylated hydrazine can be made 20 mol% or less.

After completion of the synthesis reaction, the monoallylhydrazine and the excess hydrazine aqueous solution are usually separated by distillation, and the separation is led to the purification step described later.

In the purification method of the present invention, the mixture of monoallyl hydrazine and hydrazine obtained by various methods is
Monoallylhydrazine can be purified and recovered so as not to contain hydrazine.

When treating a mixture of monoallyl hydrazine and hydrazine with an aqueous alkali solution, the preferred alkali is NaOH or KOH.

In the case of NaOH aqueous solution, if the NaOH concentration is 21% by weight or more, a two-liquid phase of NaOH phase-monoallyl hydrazine aqueous solution is formed, and hydrazine extraction operation becomes possible.

Table 1 below shows the relationship between the liquid equilibrium of the two phases.

[Table 1]

When a mixture of monoallyl hydrazine and hydrazine is treated with an aqueous alkaline solution, the resulting hydrazine is equivalent to a mixture of hydrazine in both phases of an aqueous NaOH solution and an aqueous monoallyl hydrazine solution.

Since hydrazine dissolves in an arbitrary ratio with an aqueous solution having a NaOH concentration of 37% or less, a substantial NaOH concentration for extracting only hydrazine and leaving monoallylhydrazine as an unextracted residue is preferably 26% or more, preferably 30
% Or more.

The distribution equilibrium α of hydrazine to the NaOH phase and the monoallyl hydrazine phase when treated with an aqueous solution having a NaOH concentration of 35% is almost 100. AH: monoallyl hydrazine H: hydrazine

The treatment with the alkaline aqueous solution of the present invention can be similarly carried out by a mixer-settler type batch operation or a multi-stage countercurrent type continuous operation.

The raw material monoallyl hydrazine of the present invention is extracted with hydrazine and purified by alkali treatment, but at the same time contains equilibrium water according to the alkali concentration to be treated.

It is particularly desirable to adjust the aqueous solution of monoallyl hydrazine to a corresponding concentration prior to the alkali treatment.

By the practice of the present invention, monoallylhydrazine substantially free of hydrazine can be easily obtained from a mixture of hydrazine and monoallylhydrazine.

Example 1 A stirrer, a reflux condenser, a thermometer and a dropping funnel were attached to a four-necked flask having an inner volume of 1 liter. 600 g (12 mol) of hydrated hydrazine
And cooled to 20 ° C. on a water bath. 114.6 g (1.5 mol) of allyl chloride was placed in the dropping funnel,
The reaction solution is gradually dropped so as to keep the temperature at 30 ° C. or lower.

The reaction is carried out at a molar ratio of allyl chloride to hydrazine hydrate of 1: 8. At the time when the total amount of allyl chloride has been dropped, stirring is continued for 30 minutes.
Complete the reaction.

Thereafter, 166 g of a 30% aqueous NaOH solution was used.
(1.455 mol) was dropped into the reactor from a dropping funnel to neutralize the generated HC1. When the reaction solution was analyzed, 90.3 g (1.254 mol) of monoallylhydrazine and 12.5 g (0.111 mol) of by-product (I) described later were obtained.
Mol), 1.35 g (0.012 mol) of by-product (II)
Was included.

[Example 2] The entire amount of the reaction solution obtained in Example 1 was transferred to a flask equipped with a rectification column, and
Distillation was performed in an N ₂ gas atmosphere. As the first fraction,
54.6 g of a fraction having a temperature at the top of 102 ° C. or lower was obtained.
The receiver was replaced to obtain 212.7 g of a fraction having an overhead temperature of 102 ° C to 112 ° C.

The composition of each of the first fraction and the second fraction is shown in Table 2.

[Table 2] By-product I is R ₂ NNH ₂ , and by-product II is RNNHHR
Represents a compound having the structure:

Example 3 The second fraction in Example 2 was transferred to a separating funnel, 68.1 g of solid NaOH was added, and the mixture was shaken to dissolve the NaOH. Let it.

The lower NaOH aqueous solution is removed. 89 g of a 35% aqueous NaOH solution is added to the remaining upper phase, shaken well, and allowed to stand to separate the phases. The lower NaOH aqueous solution is removed. The extraction operation with a 35% aqueous NaOH solution was further repeated twice.

Finally, 96.5 g of an aqueous solution of monoallylhydrazine was obtained in the upper phase (content: 78.1%). The obtained aqueous solution of monoallyl hydrazine was topped under reduced pressure of 55 mmHg to obtain a purified aqueous solution of monoallyl hydrazine.
6 g (content 77.8%) were obtained. The yield based on allyl chloride was 68.9%. It contained less than 0.05% by weight of hydrazine.

[0046]

According to the present invention, monoallyl hydrazine, which has been difficult to produce economically and has been difficult to purify with high purity, can be converted to allyl chloride and hydrated hydrazine in excess hydrazine aqueous solution. To produce monoallyl hydrazine with high selectivity, and by subjecting a mixture of monoallyl hydrazine and hydrated hydrazine to an extraction operation with a caustic alkali aqueous solution, hydrazine-free high-purity monoallyl hydrazine Can be easily manufactured.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07C 243/16 C07C 241/02 CA (STN)

Claims (2)

(57) [Claims] 1. A process for producing monoallyl hydrazine substantially free of hydrazine, comprising treating the mixture with an aqueous alkali solution when separating monoallyl hydrazine and hydrazine from the mixture thereof. 2. The method of claim 1 wherein the monoallyl hydrazine is combined with hydrazine.
The mixture is mixed with hydrazine in excess hydrazine aqueous solution.
Claims obtained by reacting ril chloride.
1. Monoallyl hydride substantially free of hydrazine according to 1.
Razine manufacturing method.