JPH0635424B2 - Method for producing allylamines - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing allylamines by effectively utilizing 1,2-dichloropropane.

More specifically, mainly allyl chloride and chloropropenes obtained by decomposing 1,2-dichloropropane (trans-1-chloropropene, cis-1-chloropropene and 2-chloropropene will be collectively referred to below. A decomposition product consisting of
The present invention relates to a method for producing allylamines by reacting with ammonia, primary amine or secondary amine in a liquid phase in a water solvent.

Allylamines are compounds useful as raw materials for organic synthesis and polymers for fine chemicals such as agricultural chemicals and pharmaceuticals.

(Prior Art) 1,2-Dichloropropane is a by-product in a large proportion (generally, during production of allyl chloride by high-temperature chlorination of propylene or during production of propylene oxide intermediate propylene chlorohydrin by chlorohydrination of propylene). , 5 against allyl chloride and propylene oxide
However, its use is limited to the demand as an inexpensive solvent, and the present situation is that it is hardly used effectively as a raw material for the chemical industry.

There is known a method for producing highly useful allyl chloride by dehydrochlorinating 1,2-dichloropropane by a method such as thermal decomposition (for example, JP-A-54-135712). Allyl chloride by boiling method (boiling point 45.1 ℃)
The selectivity of chloropropene is about 50 to 75%, that is, transchlorochloropropene (boiling point 37.4%).
℃), cis-1-chloropropene (boiling point 32.8 ° C) and 2-chloropropene (boiling point 22.6 ° C) and other by-products in a considerably large amount, and 1-chloropropene (especially trans isomer) Since the boiling point of a) is close to the boiling point of allyl chloride, it is considerably difficult to purify it to obtain high-purity allyl chloride.

As described above, the actual situation is that 1,2-dichloropropane has not been effectively utilized in the true sense.

(Problems to be Solved by the Invention) As described above, chloropropenes are removed from a mixture of allyl chloride and chloropropenes obtained by decomposing 1,2-dichloropropane by a usual means such as distillation. It is extremely difficult to economically separate and remove and obtain high-purity allyl chloride that can be used as a raw material for the chemical industry.

Therefore, a method (so-called reaction separation method) in which only one of allyl chloride or chloropropenes is selectively reacted in the mixture as it is and the other unreacted component is separated is considered. However, the method such as the addition reaction of chlorine or hydrogen chloride or the chlorohydrination reaction cannot achieve the purpose because allyl chloride and chloropropenes are co-reacted with each other.

Therefore, under the present circumstances, it is desired to develop a reaction separation method capable of selectively reacting with only one of allyl chloride or chloropropenes and obtaining a product with high utility value.

(Means for Solving Problems) In view of the above situation, the present inventors have proposed, as an effective utilization plan of 1,2-dichloropropane, allyl chloride and chloropropene obtained by decomposition of 1,2-dichloropropane. As a result of intensive studies on a method of selectively reacting only allyl chloride in a mixture with a compound and obtaining a highly useful product, the mixture as it is, ammonia, primary amine and secondary amine The present invention has been completed by finding that only allyl chloride can be selectively converted into allylamines by reacting with a nitrogen compound selected from the group consisting of in a liquid phase in a water solvent.

That is, the present invention is a decomposition product obtained mainly by decomposing 1,2-dichloropropane, which is mainly composed of allyl chloride and chloropropenes, as a mixture, ammonia,
A method for producing allylamines, which comprises reacting a nitrogen compound selected from the group consisting of primary amines and secondary amines in a liquid phase in an aqueous solvent.

Next, the present invention will be described in detail.

The decomposition product of 1,2-dichloropropane used in the present invention is a method of thermally decomposing 1,2-dichloropropane in the presence or absence of a catalyst, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. It can be easily obtained by various methods such as a method of reacting with an alkali.

The decomposition product of 1,2-dichloropropane obtained by the above method has a composition of about 50 to 75% of allyl chloride and about 25 to 50% of chloropropenes. In addition, 1,2
Depending on the decomposition method and decomposition rate of dichloropropane, by-products such as benzene and unreacted 1,2-dichloropropane may be contained in addition to these (in addition, unreacted 1,2-dichloropropane). (Boiling point 96.4 ° C.) can also be removed by distillation), but there is no particular problem even if these compounds are contained.

Further, as long as it has a composition equivalent to that of the decomposition product obtained in this way, it is needless to say that it can be used in the present invention.

Next, as the ammonia used in the method of the present invention, ammonia water, liquid ammonia, or the like can be arbitrarily used.

Examples of the primary amine include methylamine, ethylamine, n-propylamine, isopropylamine, n
-Butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-hexylamine, n-octylamine, ethylenediamine, hexamethylenediamine, monoethanolamine, cyclohexylamine,
Benzylamine, aniline, o-toluidine, m-toluidine, p-toluidine, -o-anisidine, p-chloroaniline, o-nitroaniline, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, β-naphthylamine. Etc.

Examples of the secondary amine include dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, N, N'-dimethylethylenediamine, N-methylethanolamine, diethanolamine, diisopropanolamine,
n-methylcyclohexylamine, N-methylbenzylamine, N-methylaniline, N-ethylaniline, N
-Methyl-m-toluidine and the like.

It should be noted that nitrogen-containing heterocyclic compounds such as ethyleneimine, azetidine, pyrrolidine, piperidine, piperazine and morpholine are also secondary amines in a broad sense, and can be used in the present invention similarly to the above-mentioned secondary amines.

As for the above-mentioned nitrogen compound, ammonia, primary amine or secondary amine, usually, one kind is arbitrarily selected and 1,2-
Used in the reaction with the decomposition products of dichloropropane,
Of course, two or more kinds can be used together.

The use ratio of the nitrogen compound to the decomposition product of 1,2-dichloropropane is generally 1 to 20 times stoichiometric amount, preferably 2 to 10 times stoichiometric amount of the nitrogen compound in terms of allyl chloride in the decomposition product. It is recommended to use it in a large excess of the theoretical amount. If the nitrogen compound is used in a large amount in excess of the upper limit of the above range, it is not economical, and if it is less than the lower limit, the product is a mixture of primary amine, secondary amine, tertiary amine, etc. Therefore, both are not preferable.

In some cases, it is not necessary to use a reaction catalyst, and 1,2
-Chloropropenes in the decomposition product of dichloropropane also have the effect of playing the role of a solvent, but water, alcohols,
It is also possible to use solvents such as ethers and hydrocarbons.

When the target allylamine is a water-soluble amine having a relatively small number of carbon atoms, the product can be used as an aqueous phase, while unreacted chloropropenes can be easily separated as an organic phase. Is particularly advantageous.

Further, a relatively weakly alkaline compound such as sodium carbonate, potassium carbonate or sodium hydrogen carbonate may be allowed to coexist as a hydrogen chloride scavenger in the reaction system.

The decomposition product of 1,2-dichloropropane may be charged into a reactor together with other raw materials (nitrogen compound, solvent, etc.), or after the other raw materials are charged into the reactor in advance, A method of continuously supplying the product can be arbitrarily adopted.

The reaction temperature cannot be uniformly defined because it depends on the reactivity of the nitrogen compound and the like, but it is usually 0 to 200.
C., preferably about 20 to 150.degree. The reaction pressure is preferably about 0 to 30 kg / cm ² G.

After completion of the reaction, the desired allylamines can be isolated by appropriately utilizing methods such as extraction and distillation.

Incidentally, when the above-mentioned hydrogen chloride scavenger is not allowed to coexist in the reaction system, either a nitrogen compound such as ammonia as a raw material or allylamines as a product is present in the form of a hydrochloride salt. After adding an alkali such as sodium hydroxide, if necessary, the above isolation operation may be performed.

(Example) Hereinafter, the present invention will be described more specifically with reference to Examples.

Reference Example 1,2-Dichloropropane Thermal Decomposition While controlling the temperature inside a quartz tube (inner diameter 2.5 cm, length 110 cm) around which an electric heater is wound to 510 ° C., 1,2- 400 dichloropropane
It was continuously charged at a flow rate of g / hr to thermally decompose 1,2-dichloropropane.

Decomposition in gaseous form from the other end of the quartz tube is condensed with a condenser cooled with ice water, hydrogen chloride contained is removed by washing with water and dried, followed by simple distillation for decolorization to decompose. The product was obtained at a rate of 260 g / hr.

As a result of analyzing the decomposition product by gas chromatography,
Its composition is 60.5% by weight of allyl chloride, 34.7% by weight of 1-chloropropene (total of trans form and cis form),
It was 2.0% by weight of 2-chloropropene, 0.3% by weight of benzene and 2.5% by weight of unreacted 1,2-dichloropropane.

Example 1 In an autoclave 1 equipped with a stirrer and a thermometer, 257 g of a 70 wt% aqueous solution of ethylamine (4 mol as ethylamine) was charged, and the internal temperature was controlled to 50 to 60 ° C. under stirring to obtain 1 in Reference Example 126.4 g (1 mol as allyl chloride) of thermal decomposition product of 2,2-dichloropropane was continuously charged over 1 hour (using a small metering pump), and further reacted at the same temperature for 3 hours. .

After completion of the reaction, the autoclave was cooled to room temperature, the contents were taken out, and 100 m of a 40 wt% concentration of sodium hydroxide aqueous solution was added under ice-cooling, and an aqueous phase (containing products and the like)
And an organic phase (mainly containing chloropropenes).
The extract (aqueous phase) obtained by extracting the organic phase twice with a total of 50 m of water was combined with the above aqueous phase, and then the product in the aqueous phase was extracted twice with a total of 400 m of ethyl ether.

The ether extract was dried over anhydrous magnesium sulfate, low boiling point components such as unreacted ethylamine and ether were distilled off, and then the desired product was rectified to obtain 66.5 g (0.782 mol) of N-ethylallylamine. Was obtained (yield based on allyl chloride: 78.2%).

On the other hand, the organic phase (46 g) was dried over anhydrous magnesium sulfate and then analyzed by gas chromatography.
Its composition is 1-chloropropene (total of trans form and cis form) 88.5% by weight, 2-chloropropene 4.4% by weight,
It was 0.7% by weight of benzene and 6.4% by weight of 1,2-dichloropropane.

Example 2 Instead of the 70% by weight aqueous solution of ethylamine of Example 1, 255.5 g (3.5 mol) of diethylamine and 1 part of water were added.
Reaction and post-treatment were carried out in the same manner as in Example 1 except that 100 m was used, and N, N-diethylallylamine 9
1.5 g (0.81 mol) was obtained (yield based on allyl chloride: 81.0%).

Example 3 In the same autoclave as in Example 1, 283 g of 30% by weight ammonia water (5 mol as ammonia), 50.4 g (0.6 mol) of sodium hydrogencarbonate and 1, obtained in Reference Example were obtained.
Charge 63.2 g of the thermal decomposition product of 2-dichloropropane (0.5 mol as allyl chloride), carry out the reaction at a temperature of 40 to 50 ° C. for 7 hours, then cool to room temperature and take out the contents. The aqueous phase (containing the product) and the oil phase (containing mainly unreacted chloropropenes) were separated. A part of the aqueous phase was collected and quantitatively analyzed by gas chromatography. As a result, the content of allylamine in the entire aqueous phase was 19.5 g (0.342 mol) (yield based on allyl chloride). : 68.4%).

(Effects of the Invention) As described in detail above, the method for producing allylamines of the present invention is characterized in that a decomposition product mainly composed of allyl chloride and chloropropenes is obtained by decomposing 1,2-dichloropropane. As-is ammonia, primary amine and 2
By reacting with a nitrogen compound selected from the group consisting of primary amines, only allyl chloride in the decomposition product can be selectively reacted to produce highly useful allylamines and unreacted chloropropenes. It is also possible to obtain a product having a purity that is industrially usable.

Moreover, in the method of the present invention, allyl chloride in the decomposition product of 1,2-dichloropropane gives a reaction result comparable to that of pure allyl chloride which is commercially available.

Therefore, according to the present invention, 1,2-dichloropropane, which has not been used so effectively in the past, can be used much more effectively, and has high industrial utility value.

Claims (1)

[Claims] 1. A decomposition product mainly composed of allyl chloride and chloropropene obtained by decomposing 1,2-dichloropropane is selected from a group consisting of ammonia, a primary amine and a secondary amine as a mixture. A method for producing allylamines, which comprises reacting a nitrogen compound according to claim 1 in a liquid phase in an aqueous solvent.