KR20070101716A - Process for preparing 1,3-propenesultone - Google Patents

Abstract

A process for preparing 1,3-propenesultone is provided to simplify the reaction device and preparation procedures, and improve selectivity and yield of preparation being available industrially by performing the process under mild conditions, making no unstable intermediates and eliminating high temperature and high vacuum processes. A process for preparing 1,3-propenesultone represented by the formula(1) comprises the steps of: (i) performing halogenation of 1,3-propanesultone by using a radical initiator and a halogenization reagent to prepare halogen-substituted 1,3-propanesultone; and (ii) performing dehydrohalogenation of the halogen-substituted 1,3-propanesultone with a base, wherein the radical initiator is azo-based compound or peroxide; the halogenation reagent is fluorine, chlorine, bromine, iodide, sulfuryl chloride(SO2Cl2), thionyl chloride, oxalyl chloride, sulfuryl fluoride, thionyl bromide or oxalyl bromide; and the base is NR^1R^2R^3 or pyridine in which R^1 to R^3 are each independently C1-12 aliphatic hydrocarbon or H.

Description

Process for preparing 1,3-propenesultone {Process for preparing 1,3-propenesultone}

The present invention relates to a method for preparing 1,3-propenesultone, and specifically, halogenates 1,3-propanesultone, and then removes a halogenated reaction. And to a process for producing 1,3-propenesultone through mild reaction conditions and a simple process.

1,3-propenesultone is a known compound used as an intermediate for pharmaceuticals, an additive for an electrolyte solution of a lithium ion secondary battery, and the like.

Chem. Commun. 1997, 611 and Tetrahedron, 1999, 2245 (WH Lee et al.) Reported the use of 1,3-propenesultone from allyl bromide compounds for 2-bromo-1,3-propanesultone through sulfonation, bromination, and cyclization. A method of synthesizing and synthesizing 1,3-propenesultone is shown.

According to the above method, in order to synthesize 1,3-propenesultone, intermediate 2,3-dibromosulfonic acid should be synthesized and cyclized to produce 2-bromo-1,3-propanesultone. In this reaction step, a temperature of 130 ° C. or higher is required at a reduced pressure of 2 mmHg or less, but under these conditions, 2,3-dibromosulfonic acid and the product 2-bromo-1,3-propanesultone are decomposed together, resulting in a severe decrease in yield. . In particular, as the amount of reactants increases, the heating conditions intensify for a long time, and thus oligomers and polymers linked together in the form of sulfonesters appear to be produced together. From this, vacuum distillation of 2-bromo-1,3-propanesultone, a desired product It tends to be difficult. Therefore, there is a problem that this method is difficult to use industrially.

In addition, Synlett, 2002, 2019 (Peter Metz et al.) Proposes a synthesis method using ring closing metathesis from vinyl intermediates, but the synthesis of vinyl intermediates is not very easy and thus difficult to use industrially.

Therefore, there is a need for a new method for industrially producing 1,3-propenesultone easily through mild reaction conditions and simple processes.

On the other hand, 1,3-propanesultone is much easier to manufacture than 1.3-propenesultone. Chem. Ber. According to 952, 85, 160 (Manecke et al.), The 1,3-propanesultone is synthesized from a 3-hydroxypropanesulfonic acid through a cyclization reaction at 150 ℃. In the cyclization reaction, 1,3-propanesultone can be obtained in high yield due to the fact that the material before and after the reaction does not have a halogen substituent, no decomposition proceeds at high temperature, and a low boiling point product is obtained after cyclization.

The present invention uses 1,3-propanesultone as a starting material, and industrially utilizes 1,3-propenesultone through mild reaction conditions and simple synthesis processes such as its halogenation reaction and hydrogen halide removal reaction. It is intended to provide a method which can be easily produced in possible yields.

The present invention comprises the following steps: i) preparing a halogen-substituted 1,3-propanesultone by carrying out a halogenation reaction on 1,3-propanesultone; And

ii) Preparation of 1,3-propenesultone of Formula 1 comprising a second step of proceeding a dehydrohalogenation reaction to the halogen-substituted 1,3-propanesultone Provide a method.

The present invention also provides 1,3-propenesultone prepared by the above method.

Hereinafter, the present invention will be described in detail.

In the production method of the present invention, 1,3-propanesultone may be used as a starting material, and 1,3-propenesultone may be prepared by sequentially performing a halogenation reaction and a hydrogen halide reaction.

In the preparation method of the present invention, the first step is to obtain a halogen-substituted 1,3-propanesultone as an intermediate for obtaining 1,3-propenesultone, which is the final product of the present invention, and the starting material 1 Through the halogenation of, 3-propanesultone. The halogen-substituted 1,3-propanesultone is preferably 2-halogen-1,3-propanesultone substituted with halogen at position 2 of 1,3-propanesultone, for example, 2-chloro-1 , 3-propanesultone and the like.

In this case, the halogenation reaction may proceed using a radical initiator and a halogenation reagent.

The halogenating reagent may be, for example, fluorine, chlorine, bromine, iodine, sulfuryl chloride (SO ₂ Cl ₂ ), thionyl chloride, oxalyl chloride, sulfuryl fluoride (sulfuryl fluoride), thionyl bromide, and oxalyl bromide may be used, and these may be used alone or in combination of two or more thereof. Preferably sulfuryl chloride (SO ₂ Cl ₂ ) can be used.

As the radical initiator, an azo compound, a peroxide, or the like can be used.

Non-limiting examples of the azo compound include 2,2'-azobisisobutyronitrile (2,2'-azobis (isobutyronitrile)), 2,2'-azobis (2-methylbutyronitrile) (2 , 2'-azobis (2-methylbutyronitrile)), 2,2'-azobis (2-methylvaleronitrile) (2,2'-azobis (2-methylvaleronitrile)), 2,2'-azobis (2 , 3-dimethylbutyronitrile) (2,2'-azobis (2,3-dimethylbutyronitrile), 2,2'-azobis (2-methylcapronitrile) (2,2'-azobis (2-methylcapronitrile)) , 2,2'-azobis (2,4-dimethylvaleronitrile) (2,2'-azobis (2,4-dimethylvaleronitrile)), and the like, and a non-limiting example of the peroxide is benzoyl peroxide (benzoyl peroxide, acetyl peroxide, di-tert-butyl peroxide, hydrogen peroxide, etc., which may be used alone or in combination of two or more thereof. Preferably 2,2'- azobisisobutyronitrile (AIBN) Can.

The reaction temperature of the halogenation reaction may be applied in the range of 40 ℃ to 150 ℃, if the reaction temperature is too low, the halogenation reaction may take a lot of time or the yield is very low, on the contrary if too high by-products of the reaction There is a problem that increases rapidly, which is undesirable. More preferably, the reaction temperature is adjusted to 70 ° C. or higher when using a 2,2′-azobisisobutyronitrile (AIBN) above the decomposition temperature of the radical initiator for stable reaction. Can be.

For example, the chlorination reaction in the halogenation reaction, since 1,3-propanesultone is a liquid phase at a set reaction temperature of 80 ℃, 2,2'- which is a radical initiator while stirring 1,3-propanesultone without a separate solvent Azobisisobutyronitrile (0.3 mol%) and sulfuryl chloride (SO ₂ Cl ₂ ) can be added dropwise. In this case, in order to minimize the non-reactive decomposition of SO ₂ Cl ₂ , the slower the dropping rate is advantageous in increasing the yield, but the dropping rate of about 1 volume% / min is preferable in order to maintain the radical reaction continuously.

The termination of the halogenation reaction is based on the disappearance of the starting material 1,3-propanesultone, which can be confirmed by gas chromatography (GC). In the case of dropwise addition and stirring at 80 ° C. for 3 hours, the conversion proceeds at a conversion rate of 70% to 90% in the GC phase. When the amount of SO ₂ Cl ₂ is excessively added dropwise to 1.5 equivalents of 1,3-propanesultone, the reaction can proceed at 100% conversion.

The product of the halogenation reaction can be confirmed through ¹ H-NMR and GC, etc., to obtain a halogen-substituted 1,3-propanesultone at position 2 or 3 of 1.3-propanesultone. For example, the product of the chlorination reaction in the halogenation reaction is 2-chloro-1,3-propanesultone and 3-chloro-1,3-propane substituted with Cl at position 2 or 3 of 1.3-propanesultone. Sultones can be produced in a molar ratio of 2: 5 to 3: 4.

The halogen-substituted 3-halogen-1,3-propanesultone at position 3 of 1.3-propanesultone has a very low acidity at position 2 of proton (H), thus dehydrohalogenation by a base such as an amine. Since the reactivity of s tends to be extremely low, it does not react in the next step of elimination reaction and remains. Thus, the desired intermediate product, 2-halogen-1,3-propanesultone, for example, only 2-chloro-1,3-propanesultone among the products of the chlorination reaction may be separated and used for the second step reaction, It can be used for the removal reaction of the second step without separate separation and purification.

When the hydrogen halide reaction is performed in the second step without a separate separation and purification as described above, two positional isomers generated by the first halogenation reaction, for example, 2-chloro-1,3 The mixture of propanesultone and 3-chloro-1,3-propanesultone is depressurized to remove most of the acid (e.g. HCl) and SO ₂ gases dissolved in the reaction mixture, then halogenated by base without further separation. The dehydrohalogenation reaction can proceed.

For example, the second stage of dehydrochlorination reaction involves reacting 2-chloro-1,3-propanesultone generated from the first stage of chlorination with a base such as an amine to give 1,3-pro Pensultone can be synthesized.

It is preferable to use a weak base as the base used in the second step of removing hydrogen. If a strong base is used, it is not preferable because a ring opening reaction of the produced 1,3-propenesultone may occur.

Non-limiting examples of the base include NR ¹ R ² R ³ Wherein R ¹ to R ³ are each independently an aliphatic hydrocarbon having 1 to 12 carbon atoms, or H), a secondary amine, a tertiary amine, pyridine, and the like, and these are alone or 2 It can mix and use species. One example of the secondary amine is diisopropylamine, and one example of the tertiary amine is triethylamine.

The dehydrohalation reaction of halogen-substituted 1,3-propanesultone with a base can be accomplished by dropwise addition of a base such as an amine to halogen-substituted 1,3-propanesultone dissolved in a solvent at room temperature. At this time, when the base is added dropwise, the hydrogen dehydrogenation reaction proceeds immediately, and the reaction can be confirmed by gas chromatography (GC). If the reaction is performed at room temperature for about 1 hour, 2-halogen-1,3-propanesultone You can see that this disappears completely.

When the amount of reactants is increased in the hydrogen halide removal reaction, it is preferable to maintain the room temperature (25 ° C.) or less using an appropriate cooling device. At a temperature above room temperature, the ring opening reaction may be performed by reaction between a base and a sulfonyl group as a side reaction.

An aromatic compound, an ether, an ester, etc. can be used as a solvent of the said hydrogen halide removal reaction. Non-limiting examples of aromatic compounds include benzene, toluene, and the like. Examples of ethers include diethyl ether and tetrahydrofuran (THF). Examples of esters include ethyl acetate, dimethyl carbonate, and the like. Two or more kinds can be mixed and used.

However, alcohols such as ethanol can react with 2-halogen-1,3-propanesultone, so they cannot be used as solvents. Alkyl halide solvents such as chloroform, dichloromethane and 1,2-dichloroethane react slowly with bases to form alkylammonium chloride. It is not suitable because it produces by-products.

After the dehydrohalation reaction, the reaction mixture may include 1,3-propenesultone, unreacted 3-halogen-1,3-propanesultone, 1,3-propanesultone, alkylammonium by-products and extra bases. . Salts such as alkylammonium chloride produced in the reaction are removed by filtration, the filtrate is concentrated, dissolved in ethyl acetate, the insoluble components are removed by filtration and concentrated again, and then recrystallized from chloroform as a white solid. -You can get propenesultone. Typically can be obtained in 35 ~ 40% yield compared to 1,3-propanesultone, and repeating the purification process twice can obtain 1,3-propenesultone purified with a purity (GC) of at least 99.5%.

EXAMPLE

Hereinafter, the present invention will be described in detail with reference to the following Examples. However, the following examples are merely to illustrate the present invention and the present invention is not limited by the following examples.

The content of each component is expressed as the area% of the peak on the detector (FID) of the gas chromatograph (Agilient Technologies, 6890N, column: J & W Scientific HP-5).

Example 1: Preparation of 1,3-propenesultone

2 kg of 1,3-propanesultone was placed in a 4L reactor equipped with a stirrer and a condenser, and purged with nitrogen at 80 ° C. for about 30 minutes. 1710 mL of SO ₂ Cl ₂ was added to a dropping funnel mounted on the reactor head. 8 g of 2,2'-azobis (isobutyronitrile) (AIBN) was dissolved in 80 mL dichloromethane, and the first 7 ml were added. After stirring the reaction mixture for 5 minutes, SO ₂ Cl ₂ was slowly added at a rate of 1v / v% / min. Added dropwise. In addition, 7 mL of AIBN solution was added every 30 minutes.

The HCl gas generated in the reaction was neutralized in a base trap containing saturated aqueous NaOH solution connected to a condenser. After the addition was completed, the reaction temperature was stirred at 80 ° C. for 1 hour. After maintaining the stirring for 1 hour, the temperature of the reactor was lowered to room temperature, and nitrogen was purge in the reaction mixture for 12 hours.

The resulting chloro-1,3-propanesultone mixture was dissolved in 1.5L benzene, and 852 g of triethylamine was slowly added dropwise at room temperature, followed by stirring for 1 hour. After completion of the reaction, the solid salt (triethylammonium chloride) included in the reaction mixture was filtered through a filter paper, and the filtrate was removed by benzene and triethylamine by using a rotary evaporator. Subsequently, the reaction mixture was dissolved in chloroform and recrystallized at 4 ° C. to give 1,3-propenesultone as a white solid. Recrystallization was repeated twice to obtain 1,3-propenesultone with 760 g (38% yield) and 99.5% (GC peak area) purity.

1,3-propenesultone and the intermediate 2-chloro-1,3-propanesultone were confirmed by NMR and Mass Spectroscopy.

1,3-propenesultone

¹ H NMR (400 MHz, DMSO-d ₆ ): δ 7.45-7.43 (m, 1H), 7.40-77.38 (m, 1H), 5.25-5.24 (t, 2H).

¹³ C NMR (100 MHz, DMSO-d ₆ ): δ 139.6, 123.2, 73.5.

MS (EI, 70 eV) m / z (120, 101, 91, 86, 66, 58, 48, 39, 29, 27).

2-chloro-1,3-propanesultone

¹ H NMR (400 MHz, CDCl ₃ ): δ 4.91 (m. 1H), 4.78 to 4.74 (dd, 1H), 4.52 to 4.48 (dd, 1H), 3.82 to 3.80 (dd, 1H), 3.59 to 3.57 (m , 1H).

MS (EI, 70 eV) m / z (64, 62, 48, 39, 27).

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the spirit and scope of the present invention based on the above contents, and the present invention is limited to the above-described exemplary embodiments. It should not be considered. In addition, the present invention is also applicable to the production of 1,3-propenesultone derivatives such as alkyl substituted 1,3-propenesultone, 1,3-propene according to the method of the present invention Preparation of sultone derivatives is also within the scope of the present invention.

As described above, the method for preparing 1,3-propenesultone according to the present invention utilizes mild reaction conditions, does not pass through an unstable intermediate, and is prepared through a two-step reaction without a high temperature, high vacuum process. This is possible. Thus, the reaction apparatus and the process are simplified, and 1,3-propenesultone can be obtained with high selectivity and yield. In addition, the manufacturing method of the present invention can be effectively applied to the production of 1,3-propenesultone used in various applications, such as additives for electrolytes of lithium ion secondary batteries, intermediates of pharmaceuticals.

Claims (12)

i) preparing a halogen-substituted 1,3-propanesultone by carrying out a halogenation reaction on 1,3-propanesultone; And ii) Preparation of 1,3-propenesultone of Formula 1 comprising a second step of proceeding a dehydrohalogenation reaction to the halogen-substituted 1,3-propanesultone Way. [Formula 1]

The method of claim 1, wherein the halogenation reaction is performed using a radical initiator and a halogenation reagent. The method of claim 2, wherein the halogenating reagent is fluorine, chlorine, bromine, iodine, sulfuryl chloride (SO ₂ Cl ₂ ), thionyl chloride, oxalyl chloride, sulfuryl fluorine A method for producing 1,3-propenesultone, characterized in that it is at least one compound selected from the group consisting of sulfuryl fluoride, thionyl bromide, and oxalyl bromide. The method of claim 2, wherein the radical initiator is at least one compound selected from the group consisting of azo compounds and peroxides. The method of claim 1, wherein the hydrogen halide removal reaction is performed using a base. The method of claim 5, wherein the base is NR ¹ R ² R ³ (Wherein R ¹ to R ³ are each independently an aliphatic hydrocarbon having 1 to 12 carbon atoms or H) and a method for producing 1,3-propenesultone, characterized in that at least one member selected from the group consisting of pyridine. The method of claim 1, wherein the halogen-substituted 1,3-propanesultone is substituted with halogen at position 2 of 1,3-propanesultone. The method of claim 1, wherein the reaction product of the first step is used for the hydrogen elimination reaction of the second step without purification. The method of claim 1, wherein the second step uses at least one selected from the group consisting of aromatic compounds, ethers, and esters as a solvent. 1,3-propenesultone prepared by the method of any one of claims 1 to 9. The 1,3-propenesultone according to claim 10, which comprises 3-halogen-1,3-propanesultone as a by-product. 11. The 1,3-propenesultone of claim 10 comprising 1,3-propanesultone which is an unreacted material.