JP2010013399A - Method for producing 2-oxazolidinone compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a 2-oxazolidinone compound in high purity in a high yield. <P>SOLUTION: The method for producing a 2-oxazolidinone compound comprises reacting a cyclic carbonate with an N-alkyl monoalkanolamine in the presence of a catalyst. Especially a catalyst for suppressing a by-product except an alkylene glycol, particularly byproduction of an N-alkyl dialkanolamine having small difference in boiling point is used and an N-alkyl monoalkanolamine is reacted with a cyclic carbonate in the presence of such a catalyst. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing a 2-oxazolidinone compound. More specifically, the present invention relates to a method capable of producing a 2-oxazolidinone compound, preferably with high purity, by suppressing and preventing the by-production of N-alkyl dialkanolamine.

  Since the 2-oxazolidinone compound of the present invention has high purity, it is useful as a solvent for lithium secondary battery electrolyte, a solvent for electrolytic capacitor electrolyte, a solvent for ink, and the like.

  The 2-oxazolidinone compounds are useful as raw materials or intermediates for polymer materials, reagents for organic synthesis reactions, pharmaceuticals, agricultural chemicals, cosmetics, chiral auxiliary agents, and the like. Conventionally, as a method for producing a 2-oxazolidinone compound, a method of reacting an amino alcohol and a cyclic carbonate (for example, see Patent Document 1) has been reported. However, the reaction product obtained by the above method contains impurities such as unreacted amino alcohol and by-product dihydroxyamine in addition to the by-product glycol. These impurities need to be separated by precision distillation or the like, but it was very difficult to obtain a high-purity 2-oxazolidinone compound by such a method. For this reason, the 2-oxazolidinone compound obtained by the above method could not be used for those requiring high purity.

For the purpose of overcoming the above problems, a method in which a reaction product of an amino alcohol and a cyclic carbonate is contacted with a cation exchange resin (see, for example, Patent Document 2); a reaction product of an amino alcohol and a cyclic carbonate is a base A method of contacting with an inorganic solid acid having adsorption ability and / or cation exchange ability (see, for example, Patent Document 3); and a reaction product of amino alcohol and cyclic carbonate with refluxing alkylene glycol at a temperature of 150 ° C. or lower under reduced pressure And / or a method of cyclization while distilling off (for example, see Patent Document 4) has been reported.
JP 59-222481 A JP-A-60-97967 JP 60-152476 A JP-A 61-7262

  However, in the methods described in Patent Documents 2 to 4, the reaction between amino alcohol and cyclic carbonate produces glycol, unreacted amino alcohol, dihydroxyamine (N-alkyl dialkanolamine), and removes these impurities. The purpose is to purify the desired product. In addition, by-products other than alkylene glycol when these amino alcohols are reacted with cyclic carbonates, particularly N-alkyl dialkanolamines, have a small difference from the boiling point of the 2-oxazolidinone compound that is the target product. Separation by distillation is difficult. For this reason, according to the methods of Patent Documents 2 to 4, there is a problem that the purity is lowered when the yield is emphasized, or the yield is lowered when the purity is emphasized. Moreover, in the method described in the said patent documents 2-4, a 2-oxazolidinone compound cannot be obtained with sufficient purity. For example, in a field such as a solvent for an electrolyte solution of a lithium secondary battery, a solvent for an electrolytic capacitor electrolyte solution, and a solvent for an ink, a higher purity 2-oxazolidinone compound is strongly desired.

  As described above, a method for producing a high-purity 2-oxazolidinone compound in a high yield with a simple method is still strongly demanded.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method capable of producing a 2-oxazolidinone compound by suppressing and preventing by-production of N-alkyl dialkanolamine by a simple method. .

  Another object of the present invention is to suppress the by-products other than alkylene glycol, particularly N-alkyl dialkanolamine having a small boiling point difference, and facilitate separation of oxazolidinones (2-oxazolidinone compounds) by distillation. Provides a method capable of producing oxazolidinones (2-oxazolidinone compounds) in a simple, high purity and high yield.

  The present inventors have obtained a high-purity 2-oxazolidinone compound in a high yield due to the above-mentioned problem, that is, by-product of by-products other than alkylene glycol, particularly N-alkyl dialkanolamine having a small difference in boiling point, during distillation. In order to solve the problem of not being able to obtain, earnest research was done. As a result, a catalyst capable of suppressing by-products other than alkylene glycol, particularly N-alkyl dialkanolamine having a small boiling point difference, is used, and in the presence of such a catalyst, N-alkylmonoalkanolamine and It has been found that the above object can be achieved by carrying out a reaction with a cyclic carbonate. Further, after the above reaction, an acid is added to the reaction solution so that the pH is 7 or less, followed by distillation; by bringing the reaction solution into contact with an adsorbent and then by distillation; or after the reaction, It was also found that a 2-oxazolidinone compound with higher purity can be easily obtained by adding an acid to the liquid so that the pH is 7 or less, bringing the acid into contact with an adsorbent, and then distilling. Based on the above findings, the present invention has been completed.

  That is, the above-mentioned object is the cyclic carbonate and the following formula (1):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
And reacting with an N-alkylmonoalkanolamine (amino alcohol) represented by the following formula (2):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
It is achieved by a method for producing a 2-oxazolidinone compound represented by the formula:

  According to the present invention, a 2-oxazolidinone compound can be economically produced by a simple method and in a high yield by suppressing and preventing by-production of N-alkyl dialkanolamine using a relatively inexpensive raw material. . Moreover, a 2-oxazolidinone compound can be obtained with higher purity by performing a purification step after the reaction according to the present invention. Accordingly, the 2-oxazolidinone compound produced by the method of the present invention is used in fields requiring high purity, for example, a solvent for a lithium secondary battery electrolyte, a solvent for an electrolytic capacitor electrolyte, a solvent for an ink, and the like. Can do.

  The present invention relates to a cyclic carbonate and the following formula (1):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
And reacting with an N-alkylmonoalkanolamine represented by the following formula (2):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
The manufacturing method of the 2-oxazolidinone compound shown by these is provided.

  Conventionally, after reacting an N-alkylmonoalkanolamine (amino alcohol) with a cyclic carbonate in the absence of a catalyst, the reaction product is brought into contact with a cation exchange resin, or a base adsorbing ability and / or cation exchanging ability is obtained. By contacting with an inorganic solid acid having a by-product, particularly N-alkyl dialkanolamine having a small boiling point difference was removed. Alternatively, a high-purity oxazolidinone can be obtained by cyclizing a reaction product of an N-alkylmonoalkanolamine and a cyclic carbonate in the absence of a catalyst while refluxing and / or distilling off alkylene glycol under reduced pressure at a temperature of 150 ° C. or lower. Was manufacturing. That is, conventionally, the reaction of N-alkylmonoalkanolamine with a cyclic carbonate is carried out in the absence of a catalyst.

  In contrast, the present invention is characterized in that the reaction between an N-alkylmonoalkanolamine and a cyclic carbonate is carried out in the presence of a catalyst. According to this method, it is possible to suppress and prevent the formation of by-products, particularly N-alkyl dialkanolamines having a small difference in boiling point, not after the reaction but during the reaction (medium).

  Embodiments of the present invention will be described below.

  In the present invention, N-alkylmonoalkanolamine is reacted with a cyclic carbonate in the presence of a catalyst. The N-alkylmonoalkanolamine used as a raw material here has the following formula (1):

It is a compound shown by these. In the above formula (1), R ¹ represents an alkyl group having 1 to 4 carbon atoms. Here, the alkyl group having 1 to 4 carbon atoms is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. Among these, R ¹ is preferably a methyl group, an ethyl group, or an n-butyl group, and more preferably a methyl group or an n-butyl group.

Moreover, in said formula (1), R < ² > and R < ³ > represents a hydrogen atom or a C1-C4 alkyl group. Here, R ² and R ³ may be the same or different. The alkyl group having 1 to 4 carbon atoms is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. Of these, R ² and R ³ are preferably hydrogen atoms.

  That is, specific examples of the N-alkylmonoalkanolamine of the above formula (1) include N-methylethanolamine, N-ethylethanolamine, Nn-propylethanolamine, N-isopropylethanolamine, Nn- Examples include butylethanolamine, N-isobutylethanolamine, N-sec-butylethanolamine, and N-tert-butylethanolamine. In the present invention, the N-alkylmonoalkanolamine of the above formula (1) may be used alone or in the form of a mixture of two or more, but is used alone. It is preferable.

  In the present invention, the amount of the N-alkylmonoalkanolamine is not particularly limited as long as it can efficiently react with the cyclic carbonate. Specifically, the amount of N-alkylmonoalkanolamine is usually stoichiometrically equimolar with the cyclic carbonate, but preferably 0.5 to 1.3 mol with respect to 1 mol of the cyclic carbonate, More preferably, it is 0.8-1.1 mol. When the reaction is carried out in such a quantitative ratio, the reaction between the N-alkylmonoalkanolamine and the cyclic carbonate can proceed efficiently.

  Moreover, the cyclic carbonate used as a raw material by this invention is not restrict | limited in particular, A well-known cyclic carbonate can be used. Examples thereof include ethylene carbonate and propylene carbonate. Of these, ethylene carbonate is more preferably used in consideration of the availability of raw materials.

  In the present invention, the reaction between the N-alkylmonoalkanolamine and the cyclic carbonate is carried out in the presence of a catalyst. Thus, by reacting a cyclic carbonate and N-alkylmonoalkanolamine in the presence of a catalyst, it is possible to suppress and prevent by-products of by-products, particularly N-alkyl dialkanolamines having a small difference in boiling point. The catalyst that can be used in the present invention is not particularly limited as long as it can suppress and prevent the formation of by-products as described above. However, the basic substance, the acid or base adsorbent, and the cation or anion exchange resin can be used. Etc. are preferred. Here, the basic substance is not particularly limited as long as it acts as a catalyst for the reaction between N-alkylmonoalkanolamine and cyclic carbonate. Specifically, metal alcoholates such as sodium methylate and potassium methylate; hydroxides such as sodium hydroxide, potassium hydroxide and calcium hydroxide; trisodium phosphate; morpholine, 4-methylmorpholine, 2,6 -Morpholines such as dimethylmorpholine, 4-ethylmorpholine, 2-morpholinoethanol; piperazine, 1-methylpiperazine, 2-methylpiperazine, 1,4-dimethylpiperazine, 2,5-dimethylpiperazine (both cis and trans isomers) 2), 2,6-dimethylpiperazine, 1-ethylpiperazine, 2- (1-piperazinyl) ethanol, 1,4-piperazinediethanol and other piperazines; imidazole, 1-methylimidazole, 2-methylimidazole, 4- Methylimidazole, 1,2-dimethyl Imidazoles such as midazole, 1-ethylimidazole, 2-ethylimidazole; 1,5-diazabicyclo [4.3.0] -5-nonene (DBN), 1,8-diazabicyclo [5.4.0] -7 -Diaza-bicyclo-alkenes such as undecene (DBU), 1,4-diazabicyclo [2.2.2] -octane (DABCO) and the like.

Moreover, as an acid or base adsorbent, Kyoward series (for example, Kyoword 100, 200, 300, 400, 500, 600, 700, 1000, 2000) (manufactured by Kyowa Chemical Industry Co., Ltd.); Mizuka Ace (acid clay) series (For example, Mizuka Ace # 20, # 200, # 300, # 400) (manufactured by Mizusawa Chemical Industry); Galeon Earth (activated clay: modified acidic clay) Series (for example, Galeon Earth V ₂ R, V ₂ , V ₁ , NV, NS, NF-2) (manufactured by Mizusawa Chemical Industry); Formula: (SiO ₂ ) _p (Al ₂ O ₃ ) _q (H ₂ O) _r [wherein p, q and r are respectively , SiO ₂ , Al ₂ O ₃ , and H ₂ O in a mass ratio (p + q + r = 100 mass%), q = 1 to 90 mass%, r = 1 to 30 mass%, p = 100−q−r And the like. Here, for example, KYOWARD 700 (manufactured by Kyowa Chemical Industry Co., Ltd.) has a composition of 10.5 mass% aluminum oxide and 60.2 mass% silicon oxide.

  Examples of the cation or anion exchange resin include cation exchange resins such as Amberlite series (for example, IR120B Na, IR124 Na, 1006F H, 2000CT Na, 252 Na, FPC3500, IRC76, IRC748) (manufactured by Organo); Series (for example, Amberlite IRA400J Cl, IRA400T Cl, IRA402J Cl, IRA402BL Cl, IRA404J Cl, IRA458RF Cl, IRA900J Cl, IRA904 Cl, IRA958 Cl, IRA410J Cl, IRA411 Cl, IRA910CT Cl, IRA4 067 , XE583, IRA743) (organo) Fat; Amberlist series (for example, Amberlist 15DRY, 15JWET, 16WET, 31WET, 35WET) (organo) and other ion exchange resins for non-aqueous solutions; Diaion series (Mitsubishi Chemical), for example, Diaion SK1B, SK104, SK110, SK112 (gel type), UBK08, UBK10, UBK12 (gel type uniform particle size product), PK208, PK212, PK216, PK218, PK220, PK228 (porous type), SK104H, SK1BH (gel type for catalyst), Strong acidity such as PK216H (porous type for catalyst), RCP145H, RCP160M (high porous type for catalyst), UKB530, UKB535, UKB530K, UKB535K, UKB555 (uniform particle size resin for chromatographic separation) Cation exchange resins, weakly acidic cation exchange resins such as WK40 (acrylic), WK10, WK11, WK100 (methacrylic), SA10A, SA12A, SA11A, NSA100, USB120 (I type gel type), PA306S, PA308, PA312 , PA316, PA318L (type I porous type), HPA25 (type I high porous type), SA20A, SA21A (type II gel type), PA408, PA412, PA418 (type II porous type), and other strongly basic cation exchange resins Low odor such as weak basic cation exchange resin such as WA10 (acrylic), WA20, WA21J, WA30 (styrene), SAF11AL, SAF12A, PAF308L (strong base I type), WA30C (styrene weak base), etc. Low elution anion exchange resin That.

  Among the above catalysts, sodium methylate, potassium methylate, sodium hydroxide, potassium hydroxide, trisodium phosphate, 4-ethylmorpholine, 1,4-dimethylpiperazine, 1-ethylimidazole, 1,5-diazabicyclo [4 , 3,0] -5-nonene (DBN), 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), 1,4-diazabicyclo [2,2,2] -octane (DABCO) , Kyoward 500, 700, 2000 (manufactured by Kyowa Chemical Industry Co., Ltd.), Amberlite IRA904 Cl, IRA410J Cl (manufactured by Organo), Amberlyst 15DRY (manufactured by Organo), Diaion SK1B, SA10A) (manufactured by Mitsubishi Chemical), Sodium methylate, sodium hydroxide, trisodium phosphate, 1 4-dimethylpiperazine, 1-ethylimidazole, 1,5-diazabicyclo [4,3,0] -5-nonene (DBN), 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), Most preferred are KYOWARD 500, 700 (manufactured by Kyowa Chemical Industry Co., Ltd.), Amberlite IRA904 Cl, IRA410J Cl (manufactured by Organo), and Amberlyst 15DRY (manufactured by Organo).

  In the present invention, the amount of the catalyst is not particularly limited as long as it can effectively catalyze the reaction between the N-alkylmonoalkanolamine and the cyclic carbonate, and the type of catalyst, reaction temperature, raw material (N-alkylmonoalkyl) It depends on the amount of water in the alkanolamine or cyclic carbonate). Specifically, when the catalyst is a basic substance, the amount of the basic substance is usually preferably 0.0001 to 0.06 mol, more preferably 0.001 to 1 mol of the cyclic carbonate. -0.04 mol. When the catalyst is an acid or base adsorbent, or a cation or anion exchange resin, the amount of the catalyst is preferably 0.001 to 20% by mass, more preferably 0, based on the cyclic carbonate. 0.01 to 10% by mass, and still more preferably 0.1 to 5% by mass. With such a quantitative ratio, the reaction between the N-alkylmonoalkanolamine and the cyclic carbonate can be favorably catalyzed. Here, when the amount of the catalyst is lower than the lower limit, a large amount of by-products, particularly N-alkyl dialkanolamine having a small difference in boiling point, is generated during the above reaction, and the subsequent purification step (for example, distillation) is performed. May have adverse effects. On the contrary, when the amount of the catalyst exceeds the upper limit, an effect commensurate with the addition cannot be obtained, which may be economically undesirable.

  The catalyst may be used as it is in the form of a solid (for example, a solid basic substance) or may be used after being dissolved, dispersed, or suspended in an appropriate solvent in advance. For example, when the catalyst is powdery and difficult to handle, such as sodium methylate, the catalyst is dissolved, dispersed, suspended in an appropriate solvent in advance and handled in the form of a solution / dispersion / suspension. The catalyst is preferable because it can be easily added. Here, the form of the catalyst in the solvent may be any form of dissolution, dispersion, or suspension, as described above, but it is preferably in the form of a solution in view of ease of handling and the like. . The solvent used at this time varies depending on the type of catalyst used, and examples thereof include water, methanol, ethanol, propanol, and isopropanol. Of these, methanol is preferable in consideration of solubility. Further, the concentration of the catalyst in the solution / dispersion / suspension when the solvent is used is not particularly limited, and is appropriately selected according to the addition amount. The concentration of the basic substance in the solution / dispersion / suspension when using the solvent is preferably 10 to 90% by mass, more preferably 20 to 50% by mass.

  In the present invention, the reaction mode between the N-alkylmonoalkanolamine and the cyclic carbonate is not particularly limited. For example, the above reaction may be carried out either batchwise or continuously. Further, the order of addition of the N-alkylmonoalkanolamine and cyclic carbonate as raw materials and the catalyst is not particularly limited. Specifically, a) a method in which a catalyst is added to an N-alkylmonoalkanolamine and then a cyclic carbonate is added thereto; a) a catalyst is added to the cyclic carbonate, and then an N-alkylmonoalkanolamine is added thereto. C) a method in which N-alkylmonoalkanolamine is added to the catalyst and then cyclic carbonate is added thereto; d) a method in which cyclic carbonate is added to the catalyst and then N-alkylmonoalkanolamine is added thereto. Any form of addition may be used. Of these, a) and c) are preferred, and a) is more preferred. At this time, the addition method is not particularly limited, and it may be added all at once or may be added stepwise or continuously by dropping or the like. However, it is preferable to add cyclic carbonate or N-alkylmonoalkanolamine stepwise or continuously by dropping or the like. This is because when a cyclic carbonate or N-alkylmonoalkanolamine is added all at once, the temperature rapidly increases due to heat of reaction, and a by-product may be easily generated.

  Further, from the viewpoint of suppressing and preventing the formation of by-products, the raw materials (cyclic carbonate, N-alkylmonoalkanolamine) and catalyst are mixed at a temperature of 25 to 80 ° C., more preferably 40 to 70 ° C. (Addition), and then it is preferably adjusted to the reaction temperature as detailed below. Further, as described above, the temperature of the mixed liquid (reaction liquid) tends to increase during the mixing / addition due to the reaction heat, but even in this case, from the viewpoint of suppressing and preventing the formation of by-products. The temperature of the mixed solution (reaction solution) is preferably maintained at 100 ° C. or lower, more preferably 50 to 100 ° C. If it is such a temperature range, the by-product of a by-product, especially N-alkyl dialkanolamine with a small boiling point difference can be suppressed and prevented. In the present invention, the temperature slightly fluctuates during each step. For this reason, the temperature in this specification includes the fluctuation | variation of about +/- 5 degreeC.

  The reaction conditions for the N-alkylmonoalkanolamine and the cyclic carbonate are not particularly limited, but preferably, the raw materials (cyclic carbonate, N-alkylmonoalkanolamine) and the catalyst are mixed and added at the temperature as described above. Thereafter, it is preferable to carry out the reaction by heating / cooling the mixed solution (reaction solution) to a predetermined temperature if necessary. For example, the reaction temperature between the N-alkylmonoalkanolamine and the cyclic carbonate is such that the raw materials (cyclic carbonate, N-alkylmonoalkanolamine) and the catalyst are not solidified, the reaction proceeds, and a by-product, particularly the boiling point difference. If it is the temperature which suppresses and prevents the production | generation of small N-alkyl dialkanolamine, there will be no restriction | limiting in particular. The reaction time is not particularly limited, and is appropriately selected depending on the amount of raw materials and catalyst charged, the reaction temperature, and the like. Specifically, the reaction is preferably performed at a temperature of 25 to 140 ° C., more preferably 60 to 100 ° C., preferably 0.1 to 10 hours, more preferably 1 to 5 hours. When the said reaction temperature is less than a minimum, reaction rate becomes slow and reaction may not advance efficiently. On the other hand, when the reaction temperature exceeds the upper limit, by-products, particularly N-alkyl dialkanolamines having a small difference in boiling point, are likely to be produced, and the yield and purity may be reduced. The reaction may be performed under normal pressure, reduced pressure, or increased pressure, but is preferably performed under normal pressure in consideration of ease of operation. The reaction of N-alkylmonoalkanolamine and cyclic carbonate may be carried out in a solvent that is inert to the raw materials and the catalyst (does not participate in the reaction), but from an economic and industrial viewpoint, the solvent Is preferably not used separately.

  As described above, a 2-oxazolidinone compound is produced by reacting a cyclic carbonate and an N-alkylmonoalkanolamine in the presence of a catalyst. Here, the completion of the reaction (production of 2-oxazolidinone compound or by-product) can be monitored by a known method such as liquid chromatography or gas chromatography. In addition, according to the method of the present invention, the reaction product after completion of the above reaction hardly contains by-products, particularly N-alkyl dialkanolamines having a small boiling point difference, that is, difficult to remove. Specifically, the content of N-alkyl dialkanolamine in the crude 2-oxazolidinone compound is usually 0.3 GCarea% or less, more preferably 0.0 to 0.27 GCarea%. The content is usually 40 GCare% or less, more preferably 20 to 36 GCare%. Of the by-products, alkylene glycol can be easily removed from the reaction product by a purification step, particularly a purification step as described below. Here, content of the said by-product (N-alkyl dialkanolamine, alkylene glycol) is the value measured by the gas chromatography described in the following Example. Moreover, the detection limits of N-alkyl dialkanolamine and alkylene glycol by gas chromatography under the conditions of the following examples are 100 ppm and 30 ppm, respectively. Further, the purity of the reaction product (crude 2-oxazolidinone compound) immediately after the reaction according to the present invention without undergoing a purification step is not limited to the following, but is usually 60 GCare% or more, more preferably 64-80 GCare%.

  In the present invention, a separate purification step may be performed for the purpose of further improving the purity of the reaction product obtained by the above reaction and / or removing the catalyst used in the above reaction. In the case of performing the purification step, the purification step is not particularly limited, and known purification methods such as JP-A-60-97967, JP-A-60-152476, JP-A-61-7262 and the like can be used. It can be used in the same manner or appropriately modified. For example, (a) a reaction product obtained by reacting a cyclic carbonate with an N-alkylmonoalkanolamine is brought into contact with an adsorbent and then distilled; (b) a cyclic carbonate and an N-alkylmonoalkanolamine. An acid is added to the reaction product obtained by the reaction of (2) and then distilled, and (c) a combination with (a) and (b) above is preferably used. The purification process is not limited to the specific embodiment described above.

  Hereinafter, the preferred embodiments (a), (b) and (c) will be described in detail.

In the embodiment (a), first, the reaction product is brought into contact with an adsorbent. As a result, the catalyst (basic substance) used in the above reaction is adsorbed and removed, so that side reactions during distillation in the next step are suppressed. Here, the adsorbent used is not particularly limited, and a known adsorbent can be used. For example, acid clay, activated clay such as galeon earth (manufactured by Mizusawa Chemical Industry Co., Ltd.), bentonite, 9SiO ₂ · Al ₂ O ₃ · αH ₂ O (α = 0 to 2), KYOWARD 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) , KYOWARD 700 (manufactured by Kyowa Chemical Industry Co., Ltd .; aluminum oxide 10.5 mass%, silicon oxide 60.2 mass%), etc., formula: (SiO ₂ ) _p (Al ₂ O ₃ ) _q (H ₂ O) _r [wherein, p, q and r are mass ratios of SiO ₂ , Al ₂ O ₃ and H ₂ O (p + q + r = 100 mass%), q = 1 to 90 mass%, r = 1, respectively] To 30% by mass, p = 100-qr], Tomix AD-700 (manufactured by Tomita Pharmaceutical Co., Ltd.), Tomix AD-600 (manufactured by Tomita Pharmaceutical Co., Ltd.), cation exchange resin, diatomaceous earth And fine powder silicic acid. Of these, Kyoward 700, acid clay, and activated clay are preferable, and Kyoword 700 is more preferable. Moreover, the said adsorbent may be used independently or may be used with the form of a 2 or more types of mixture. Further, the amount of the adsorbent used is not particularly limited as long as it is an amount that can sufficiently adsorb and remove the catalyst (basic substance). The use amount of the adsorbent is preferably in the range of 25 to 60 times, more preferably 30 to 45 times in terms of mass ratio with respect to the addition amount of the catalyst (basic substance).

  The conditions for contacting the reaction product with the adsorbent are not particularly limited as long as the catalyst (basic substance) can be sufficiently adsorbed and removed. Specifically, after adding an adsorbent to the reaction product, the reaction product is 25-100 ° C., more preferably 50-80 ° C., for 0.1-10 hours, more preferably 2-5 hours. It is preferable to contact the adsorbent. Here, in order to improve the contact between the reaction product and the adsorbent, the mixture may be stirred. After contacting the reaction product with the adsorbent, the adsorbent is separated and removed by filtration, liquid separation, etc., and the filtrate is distilled (eg, vacuum distillation). Here, the distillation conditions are not particularly limited, and can be appropriately selected depending on the kind of the 2-oxazolidinone compound that is the target product. For example, the pressure at the time of distillation is selected so that the temperature in the kettle is 200 ° C. or lower, more preferably 100 to 160 ° C. If the temperature in the kettle exceeds 200 ° C., side reactions may occur, leading to a decrease in yield. By such distillation, the target 2-oxazolidinone compound can be easily separated from the reaction solution.

  In the embodiment (b), first, an acid is added to the reaction product so that the pH is 7 or less. Thereby, since the catalyst (basic substance) used in the said reaction forms an acid and a salt, the side reaction at the time of distillation of the following process is suppressed. For this reason, by adding an acid so that the reaction solution becomes acidic (predetermined pH), the target 2-oxazolidinone compound can be obtained with high purity and high yield. Here, the acid used is not particularly limited as long as it can form a salt with the catalyst (basic substance), and any of inorganic acids and organic acids can be used. For example, inorganic acids such as phosphoric acid, polyphosphoric acid, sulfuric acid, boric acid, hydrochloric acid; formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, benzoic acid, phthalic acid, phenylacetic acid, Examples include acetic anhydride, maleic anhydride, phthalic anhydride, and organic acids such as p-toluenesulfonic acid. Of these, phosphoric acid and sulfuric acid are preferable, and phosphoric acid is more preferable. Moreover, the said acid may be used independently or may be used with the form of 2 or more types of mixtures. Furthermore, the amount of acid added is not particularly limited as long as the pH of the reaction product is 7 or less. Preferably, the acid is added so that the pH of the reaction product is 3-7, more preferably 4-6. When an acid is added so as to have such a pH, the catalyst can be efficiently separated and removed, side reactions in the distillation in the next step can be sufficiently suppressed and prevented, and a high yield can be achieved. In particular, if the pH exceeds 7, side reactions may occur in the kettle during distillation, and the yield of the target 2-oxazolidinone compound may be reduced.

  The conditions for adding the acid to the reaction product are not particularly limited as long as they can form a sufficient salt with the catalyst (basic substance). Specifically, after adding the acid to the reaction product, the reaction product is 25-100 ° C., more preferably 40-70 ° C., for 0.1-3 hours, more preferably 0.5-2 hours. It is preferable to contact the acid. After the reaction product and acid are sufficiently brought into contact with each other to form a salt, the salt may be separated and removed by filtration, liquid separation, etc., and then distilled (for example, distillation under reduced pressure). Here, the distillation conditions are not particularly limited, and can be appropriately selected depending on the kind of the 2-oxazolidinone compound that is the target product. For example, the pressure at the time of distillation is selected so that the temperature in the kettle is 200 ° C. or lower, more preferably 100 to 160 ° C. If the temperature in the kettle exceeds 200 ° C., side reactions may occur, leading to a decrease in yield. By such distillation, the target 2-oxazolidinone compound can be easily separated from the reaction solution.

  As described above, by further purifying the reaction product of cyclic carbonate and N-alkylmonoalkanolamine, by-products, particularly N-alkyldialkanolamine having a small difference in boiling point, are contained in the 2-oxazolidinone compound. The amount can be further reduced. Specifically, the purity of the 2-oxazolidinone compound after the purification step is 99.0 GCare% or more, more preferably 99.5 to 100 GCare%. Further, the content of N-alkyl dialkanolamine in the 2-oxazolidinone compound after the purification step is usually 0.1 GCarea% or less, more preferably 0.0 to 0.07 GCarea%, and the content of alkylene glycol The amount is usually 0.2 GCarea% or less, more preferably 0.0 to 0.1 GCarea%. In addition, content of the said by-product (N-alkyl dialkanolamine, alkylene glycol) is the value measured by the gas chromatography described in the following Example. Moreover, the detection limits of N-alkyl dialkanolamine and alkylene glycol by gas chromatography under the conditions of the following examples are 100 ppm and 30 ppm, respectively.

  In the above embodiment (c), this step is carried out after the above embodiment (a) by carrying out the embodiment (b), that is, the reaction product obtained by the reaction between the cyclic carbonate and the N-alkylmonoalkanolamine. In contact with the adsorbent, and after adding the acid so that the pH is 7 or less, distill; or after embodiment (b), embodiment (a) is carried out, ie cyclic carbonate and N-alkyl mono An acid may be added to the reaction product obtained by the reaction with the alkanolamine so that the pH is 7 or less, and after contacting with the adsorbent, distillation may be performed. In view of the ease of separation of the 2-oxazolidinone compound, it is preferable to carry out the embodiment (a) after the embodiment (b). Moreover, about the contact process with an adsorbent, the addition process of an acid, and the distillation process in embodiment (c), since the process similar to the said embodiment (a) and (b) is applicable, these description is demonstrated. It is omitted here.

  According to the method of the present invention, a 2-oxazolidinone compound can be produced with a high yield and high purity by a simple method. In particular, the 2-oxazolidinone compound produced by the method of the present invention contains almost no by-products, particularly N-alkyl dialkanolamines having a small boiling point difference. For this reason, the 2-oxazolidinone compound produced by the method of the present invention is used as a raw material or intermediate for polymer materials, reagents for organic synthesis reactions, pharmaceuticals, agricultural chemicals, cosmetics, chiral adjuvants, etc. It is useful as a solvent for a lithium secondary battery electrolyte solution that requires high purity, a solvent for an electrolytic capacitor electrolyte solution, a solvent for ink, and the like.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following, “%” means “mass%” unless otherwise specified.

  The amounts of alkylene glycol and N-alkyl dialkanolamine, which are by-products, were measured by gas chromatography under the following conditions. Moreover, the detection limits of alkylene glycol and N-alkyl dialkanolamine by gas chromatography under the following conditions are 30 ppm and 100 ppm, respectively. In addition, the said detection limit is the minimum detectable concentration which adjusted the methanol glycol and N-alkyl dialkanolamine to arbitrary density | concentrations, respectively, and analyzed this on the following gas chromatograph analysis conditions.

<Measurement method of the amount of alkylene glycol and N-alkyl dialkanolamine>
-Gas chromatograph analysis conditions Model: GC4000 manufactured by GL Sciences
Column: CP-volamine (60 m × 0.32 mm ID) manufactured by Varian
Column temperature:
3-methyl-2-oxazolidinone 150 ° C. (hold for 3 minutes) → temperature rise at 20 ° C. per minute → 270 ° C. (hold for 11 minutes)
3-Butyl-2-oxazolidinone 230 ° C. (hold for 3 minutes) → Temperature rise at 20 ° C./minute→270° C. (hold for 20 minutes)
Vaporization chamber temperature: 275 ° C
Detector temperature: 275 ° C
Sample injection volume: 0.2 μl
Example 1
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, N-methylethanolamine 751 g (10 mol) and 28% sodium methylate / methanol solution 16.3 g (0.085 mol) at room temperature (25 ° C.) Then, 881 g (10 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of dropping, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction liquid after completion of the reaction by gas chromatography under the above conditions, N-methyldiethanolamine was not detected, and the content of impurities other than ethylene glycol was 0.1 GCare% or less.

  Next, 170 g of Kyoward 700 (manufactured by Kyowa Chemical Industry Co., Ltd.) is added to the reaction solution obtained by the above reaction, and after contacting with the reaction solution at 80 ± 5 ° C. for 2 hours, Kyoward 700 is separated by filtration. did. Subsequently, the reaction solution was distilled under reduced pressure to obtain 863 g (8.5 mol) of 3-methyl-2-oxazolidinone at a boiling point of 130 ° C./20 mmHg. As a result of analyzing the obtained 3-methyl-2-oxazolidinone by gas chromatography under the above conditions, the purity of 3-methyl-2-oxazolidinone was 99.95 GCarea%, and N-methyldiethanolamine was not detected. .

Example 2
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, N-methylethanolamine 751 g (10 mol) and 28% sodium methylate / methanol solution 49.0 g (0.25 mol) at room temperature (25 ° C.) Then, 881 g (10 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of dropping, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, N-methyldiethanolamine was not detected, and the content of impurities other than ethylene glycol was 0.5 GCare% or less.

  Next, 24.6 g of phosphoric acid was added to the reaction solution obtained by the above reaction, and contacted with the reaction solution at 50 ± 5 ° C. for 2 hours. As a result, the pH was 6.8. Subsequently, by distillation under reduced pressure, 916 g (9.1 mol) of 3-methyl-2-oxazolidinone was obtained at a boiling point of 130 ° C./20 mmHg. As a result of analyzing the obtained 3-methyl-2-oxazolidinone by gas chromatography under the above conditions, the purity of 3-methyl-2-oxazolidinone was 99.67 GCarea%, and N-methyldiethanolamine was not detected. .

Example 3
In a flask equipped with a stirrer, a thermometer and a rectifying tower, 11.62 g (10 mol) of Nn-butylethanolamine and 61.6 g (0.31 mol) of a 28% sodium methylate / methanol solution at room temperature (25 C.), and 881 g (10 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropping, a reaction between Nn-butylethanolamine and ethylene carbonate was performed at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, the content of Nn-butyldiethanolamine was 0.03 GCarea%, and the content of impurities other than ethylene glycol was 1.3 GCarea%. It was.

  Next, 39.0 g of phosphoric acid was added to the reaction solution obtained by the above reaction, and contacted with the reaction solution at 50 ± 5 ° C. for 2 hours. As a result, the pH was 5.1. Next, 61.6 g of Kyoward 700 (manufactured by Kyowa Chemical Industry Co., Ltd.) was added and contacted with the reaction solution at 80 ± 5 ° C. for 2 hours, and then phosphate and Kyoward 700 were separated and removed by filtration. Thereafter, the filtrate was distilled under reduced pressure to obtain 1244 g (8.7 mol) of 3-n-butyl-2-oxazolidinone at a boiling point of 130 ° C./4 mmHg. The obtained 3-n-butyl-2-oxazolidinone was analyzed by gas chromatography under the above conditions. As a result, the purity of 3-n-butyl-2-oxazolidinone was 99.85 GCarea% and Nn-butyl The content of diethanolamine was 0.04 GCarea%.

Example 4
In a flask equipped with a stirrer, a thermometer and a rectifying column, 75.1 g (1.0 mol) of N-methylethanolamine and 0.8 g (0.02 mol) of sodium hydroxide at room temperature (25 ° C.) 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction liquid after completion of the reaction by gas chromatography under the above conditions, N-methyldiethanolamine was not detected, and the content of impurities other than ethylene glycol was 0.7 GCare%.

Example 5
In a flask equipped with a stirrer, a thermometer and a rectifying column, 75.1 g (1.0 mol) of N-methylethanolamine was added to 2.5 g of 1,5-diazabicyclo [4.3.0] -5-nonene. (0.02 mol) was charged at room temperature (25 ° C.), and 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, N-methyldiethanolamine was not detected, and the content of impurities other than ethylene glycol was 1.4 GCare%.

Example 6
In a flask equipped with a stirrer, a thermometer and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine and 1.6 g (1.8%) of KYOWARD 500 (manufactured by Kyowa Chemical Industry Co., Ltd.) Was charged at room temperature (25 ° C.), and 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.16 GCarea% and the content of impurities other than ethylene glycol was 1.5 GCarea%.

Example 7
In a flask equipped with a stirrer, a thermometer and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine was added 1.6 g (1.8%) of Amberlite IRA904 Cl (organo) at room temperature. (25 ° C.), 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction liquid after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.20 GCarea%, and the content of impurities other than ethylene glycol was 2.1 GCarea%.

Example 8
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine and 1.6 g (1.8%) of KYOWARD 700 (manufactured by Kyowa Chemical Industry Co., Ltd.) Was charged at room temperature (25 ° C.), and 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.23 GCarea% and the content of impurities other than ethylene glycol was 1.5 GCarea%.

Example 9
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine was added 1.6 g (1.8%) of Amberlite IRA410J Cl (organo) at room temperature. (25 ° C.), 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.24 GCarea% and the content of impurities other than ethylene glycol was 1.8 GCarea%.

Example 10
In a flask equipped with a stirrer, a thermometer, and a rectifying column, 75.1 g (1.0 mol) of N-methylethanolamine and 2.3 g (0.02 mol) of 1,4-dimethylpiperazine at room temperature (25 C.), 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction liquid after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.25 GCarea%, and the content of impurities other than ethylene glycol was 1.9 GCarea%.

Example 11
In a flask equipped with a stirrer, a thermometer and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine and 1.9 g (0.02 mol) of 1-ethylimidazole at room temperature (25 ° C.) Then, 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction liquid after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.25 GCarea%, and the content of impurities other than ethylene glycol was 2.1 GCarea%.

Example 12
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine was added 1.6 g (1.8%) of Amberlyst 15DRY (manufactured by Organo) at room temperature ( 25.degree. C.), 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the heat of reaction. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. As a result of analyzing the reaction solution after completion of the reaction by gas chromatography under the above conditions, the content of N-methyldiethanolamine was 0.27 GCarea% and the content of impurities other than ethylene glycol was 1.6 GCarea%.

Example 13
In a flask equipped with a stirrer, a thermometer, and a rectifying tower, 75.1 g (1.0 mol) of N-methylethanolamine and 4.9 g (0.03 mol) of trisodium phosphate are at room temperature (25 ° C.). Then, 88.1 g (1.0 mol) of ethylene carbonate was added dropwise thereto. During the dropping, the dropping of ethylene carbonate was adjusted so that the temperature of the reaction solution did not exceed 80 ° C. due to the reaction heat. After completion of the dropwise addition, N-methylethanolamine and ethylene carbonate were reacted at 80 ± 5 ° C. for 1 hour. The reaction solution after completion of the reaction was analyzed by gas chromatography under the above conditions. As a result, the content of N-methyldiethanolamine was 0.26 GCarea% and the content of impurities other than ethylene glycol was 2.1 GCarea%.

Comparative Example 1
The following experiment was conducted according to the method described in Japanese Patent Application Laid-Open No. 61-7262.

  That is, in a flask equipped with a stirrer, a thermometer, and a rectifying tower, 751 g (10 mol) of N-methylethanolamine and 881 g (10 mol) of ethylene carbonate were charged. The mixture was reacted at 90 ± 10 ° C. for 3 hours. Next, ethylene glycol was distilled off at 125 ± 5 ° C. under reduced pressure. About the reaction liquid after distillation, as a result of measuring the residual ethylene glycol content in crude 3-methyl-2-oxazolidinone by gas chromatography under the above conditions, it was found to be 0.5 GCare%. The reaction solution was further cooled to room temperature (25 ° C.). At this time, the content of N-methyldiethanolamine in the crude 3-methyl-2-oxazolidinone was 1.3 GCare%.

  Next, 9.9 g of sulfuric acid was added to the crude 3-methyl-2-oxazolidinone obtained in the above reaction, and contacted with the reaction solution at 50 ± 5 ° C. for 2 hours. The pH was 3.6. . Subsequently, the reaction solution was distilled under reduced pressure to obtain 840 g (8.3 mol) of 3-methyl-2-oxazolidinone at a boiling point of 130 ° C./20 mmHg. The obtained 3-methyl-2-oxazolidinone was analyzed by gas chromatography under the above conditions. As a result, the purity of 3-methyl-2-oxazolidinone was 99.15 GCare% and the content of N-methyldiethanolamine was 0.00. It was 32 GCare%.

Claims (3)

Cyclic carbonate and the following formula (1):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
And reacting with an N-alkylmonoalkanolamine represented by the following formula (2):

However, ^{R 1} is an alkyl group having 1 to 4 carbon atoms, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
The manufacturing method of 2-oxazolidinone compound shown by these.   The method for producing a 2-oxazolidinone compound according to claim 1, wherein the catalyst is at least one selected from the group consisting of a basic substance, an acid or base adsorbent, and a cation or anion exchange resin. (A) The reaction product obtained by the reaction of the cyclic carbonate and N-alkylmonoalkanolamine is distilled after contacting with the adsorbent.
(B) An acid is added to the reaction product obtained by the reaction of the cyclic carbonate and N-alkylmonoalkanolamine so that the pH of the reaction product is 7 or less, and then distillation, or (c) An acid is added to the reaction product obtained by the reaction of the cyclic carbonate and N-alkylmonoalkanolamine so that the pH of the reaction product is 7 or less, and after contact with the adsorbent, distillation is performed.
The method for producing a 2-oxazolidinone compound according to claim 1, further comprising: