JP2004331520A - Method for producing 2,5-bis(isocyanatomethyl)-1,4-dithianes and intermediate therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing 2,5-bis(isocyanatomethyl)-1,4-dithianes without problems such as post-treatment and to provide an intermediate for production and a method for producing the same. <P>SOLUTION: The method for producing the 2,5-bis(isocyanatomethyl)-1,4-dithianes represented by formula (I) (wherein, Rs denote each a hydrogen atom or a 1-6C alkyl group) is carried out as follows. A compound represented by formula (II) (wherein, R<SB>1</SB>s, R<SB>2</SB>s and R<SB>3</SB>s denote each independently a 1-6C alkyl group or an aryl group) which is an intermediate for production thereof is heated. The method for producing the compound represented by formula (II) comprises reacting a compound represented by formula (III) with phosgene. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００９】
（式中、Ｒ^１、Ｒ^２およびＲ^３はそれぞれ独立に、Ｃ１〜Ｃ６アルキル基またはアリール基を表し、Ｒは、水素原子またはＣ１〜Ｃ６アルキル基を表す。）で表される化合物を加熱することを特徴とする、式（Ｉ）
【００１０】
【化９】

【００１１】
（式中、Ｒは前記と同じ意味を表す。）で表される２，５−ビス（イソシアナトメチル）−１，４−ジチアン類の製造方法が提供される。
本発明の２，５−ビス（イソシアナトメチル）−１，４−ジチアン類の製造方法は、式（ＩＩＩ）
【００１２】
【化１０】

【００１３】
（式中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表す。）で表される化合物とホスゲンを反応させることにより、式（ＩＩ）
【００１４】
【化１１】

（式中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表す。）で表される化合物を得、次いで、得られた式（ＩＩ）で表される化合物を加熱するものであるのが好ましい。
【００１５】
本発明の第２によれば、式（ＩＩ）
【００１６】
【化１２】

【００１７】
（式中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表す。）で表される化合物が提供される。このものは、本発明に係る２，５−ビス（イソシアナトメチル）−１，４−ジチアン類の製造中間体である。
本発明の第３によれば、式（ＩＩＩ）
【００１８】
【化１３】

【００１９】
（式中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表す。）で表される化合物とホスゲンを反応させることを特徴とする、式（ＩＩ）
【００２０】
【化１４】

【００２１】
（式中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表す。）で表される化合物の製造方法が提供される。
【００２２】
【発明の実施の形態】
以下、本発明について、詳細に説明する。
本発明の２，５−ビス（イソシアナトメチル）−１，４−ジチアン類の製造方法の概要を下記に示す。
【００２３】
【化１５】

【００２４】
本発明の製造方法に用いる式（ＩＩ）で表される化合物は、新規化合物である。
式（ＩＩ）中、Ｒは水素原子またはＣ１〜Ｃ６アルキル基を表す。Ｃ１〜Ｃ６アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基等が挙げられる。
【００２５】
Ｒ^１、Ｒ^２およびＲ^３はそれぞれ独立に、Ｃ１〜Ｃ６アルキル基またはアリール基を表す。Ｃ１〜Ｃ６アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、ｓ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基等が挙げられ、アリール基の具体例としては、フェニル基、ｐ−メトキシフェニル基等が挙げられる。
式（ＩＩ）で表される化合物の具体例としては、下記第１表に示すものが挙げられる。
【００２６】
【表１】

【００２７】
前記式（ＩＩ）で表される化合物は、前記式（ＩＩＩ）で表されるアミン化合物またはその塩を、ホスゲンと反応させることにより得ることができる。
【００２８】
この反応を行う方法としては、例えば、式（ＩＩＩ）で表されるアミン化合物またはその塩を含む溶液にホスゲンを添加する方法、または、ホスゲンを溶解した溶液に式（ＩＩＩ）で表されるアミン化合物もしくはその塩またはその溶液を添加する方法が挙げられる。
【００２９】
上記反応は、適当な溶媒中で行うことができる。用いる溶媒としては、反応に不活性なものであれば特に制限されない。例えば、クロロベンゼン、トルエン、キシレン、ニトロベンゼン、ベンゾトリフルオリド、ベンゾニトリル等の芳香族炭化水素類；クロロホルム、１，２−ジクロロエタン、塩化メチレン等のハロゲン化炭化水素類；アセトニトリル、プロピオニトリル等のニトリル類；テトラヒドロフラン、ジオキサン等のエーテル類；アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類；酢酸メチル、酢酸エチル、酢酸イソプロピル等のエステル類；等が挙げられる。
【００３０】
反応は、−５℃〜＋１００℃の温度範囲で行うのが好ましく、５℃〜２０℃の範囲で行うのがさらに好ましい。
ホスゲンの使用量は特に制限されないが、式（ＩＩＩ）で表されるアミン化合物１モルに対して、通常１〜２０モル、好ましくは１．５〜１０モルの範囲である。
【００３１】
また、この反応においては、脱ハロゲン化剤として３級アミンを共存させて反応させることができる。
３級アミンの具体例としては、トリメチルアミン、トリエチルアミン、トリ−ｎ−ブチルアミン、Ｎ，Ｎ−ジメチルシクロヘキシルアミン、Ｎ，Ｎ−ジエチルアニリン、ピリジン、キノリン、Ｎ，Ｎ−ジメチルアミノピリジン等が挙げられる。
【００３２】
３級アミンの使用量は、前記式（ＩＩＩ）で表されるアミン化合物１モルに対して、１．０〜１．５モルの範囲が好ましい。式（ＩＩＩ）で表される化合物の塩を用いる場合には、該塩の中和に必要な量をさらに添加する必要がある。
３級アミンを用いる場合、３級アミンは、ホスゲンを添加する前に式（ＩＩＩ）で表されるアミン化合物の溶液に添加しても、ホスゲンを添加後に添加してもよい。
【００３３】
式（ＩＩ）で表される化合物そのものは不安定であるため、反応後、単離精製することなく、そのまま次工程に供するのが好ましい。また、一部もしくは全部の溶媒を置換して次工程に供することもできる。
また、脱塩素化剤として３級アミンを使用した場合は、生成する塩を水洗、または濾過により除去したのち、そのままで、または、一部もしくは全部の溶媒を置換して次工程に供することもできる。
【００３４】
式（ＩＩ）で表される化合物は、式（ＩＩ）で表される化合物と１級または２級アミンと反応させて、安定なウレア体に誘導することで、式（ＩＩ）で表される化合物の生成を確認することができる。
【００３５】
式（ＩＩ）で表される化合物の製造に用いられる式（ＩＩＩ）で表されるアミン化合物中、Ｒ、Ｒ^１、Ｒ^２およびＲ^３は前記と同じ意味を表し、同様の具体例を例示することができる。
式（ＩＩＩ）で表されるアミン化合物は、対応するハロゲン化合物と対応するアミンより容易に製造することができる。
また、式（ＩＩＩ）で表されるアミン化合物の塩は、例えば、アミン化合物に塩酸ガスを反応させることで容易に製造することができる。
【００３６】
本発明は、式（ＩＩ）で表される化合物を、熱分解して式（Ｉ）で表されるイソシアネートを製造することを特徴とする。
【００３７】
式（ＩＩ）で表される化合物の熱分解の方法として、具体的には、式（ＩＩ）で表される化合物を溶媒中加熱する方法を例示することができる。
【００３８】
用いる溶媒としては、クロロベンゼン、トルエン、キシレン、ニトロベンゼン、ベンゾトリフルオリド、ベンゾニトリル等の芳香族炭化水素類；クロロホルム、１，２−ジクロロエタン、塩化メチレン等のハロゲン化炭化水素類；アセトニトリル、プロピオニトリル等のニトリル類；テトラヒドロフラン、ジオキサン等のエーテル類；アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類；酢酸メチル、酢酸エチル、酢酸イソプロピル等のエステル類；等を例示することができる。
【００３９】
反応は、単に加熱するだけで進行するが、反応系内がホスゲンの分解等により酸性になっている場合、酸の存在は反応の妨げとなるため、有機塩基、例えばトリエチルアミン、トリｎ−ブチルアミンなどの３級アミンやピリジン類等を反応系に添加するのが好ましい。
【００４０】
反応は溶媒の沸点温度で進行するが、１００℃以上で行うのが好ましい。また、触媒として塩化第二鉄などのルイス酸等を添加することもできる。
【００４１】
また本発明では、式（ＩＩＩ）で表されるアミン化合物を必要に応じて塩酸ガス等を吹き込んで塩酸塩化した後、ホスゲンガスを吹き込み加熱することにより、または、加熱しながらホスゲンガスを吹き込むことにより、ホスゲン化、熱分解を連続して行うことで、目的とする式（Ｉ）で表されるイソシアネートを得ることもできる。
【００４２】
本発明の製造方法により得られる２，５−ビス（イソシアナトメチル）−１，４−ジチアン類を重合させて得られるポリマーは透明性に優れ、屈折率が高いという特性を有し、レンズ樹脂材料として有用である。
【００４３】
【実施例】
次に、実施例により本発明を更に詳細に説明するが、本発明は以下の実施例に限定されるものではない。
（実施例１）
２，５−ビス（ｔ−ブチルアミノメチル）−１，４−ジチアン（ＴＢＭＤ）６．３１ｇ（純度９２％、０．０２ｍｏｌ）をモノクロロベンゼン（１７０ｍｌ）に溶解させたのち、トリエチルアミン４．４４ｇ（０．０４４ｍｏｌ）を加え、５℃まで冷却した。冷却後ホスゲンガス２１．３ｇ（０．２２ｍｏｌ）を吹き込み、６時間攪拌し、２，５−ビス（ｔ−ブチル−クロロカルボニルアミノメチル）−１，４−ジチアン（ＢＣＭＤ）を合成した。
反応液の一部をとり、ここにＮ−メチルアニリンを大過剰加え、生成したウレア体をカラムクロマトグラフィーにより単離精製した。得られたウレア誘導体のＮＭＲスペクトル（核磁気共鳴スペクトル）を測定することにより、得られたウレア誘導体は、下記に示す化合物であることが確認された。
【００４４】
【化１６】

【００４５】
^１Ｈ−ＮＭＲ（ＣＤＣｌ_３，δｐｐｍ）：１．４３（１８Ｈ，Ｓ），２．５〜３．２（１０Ｈ，ｍ），３．２０（６Ｈ，ｓ），７．１１〜７．１７（６Ｈ，ｍ），７．３０〜７．３８（４Ｈ，ｍ）
【００４６】
^１３Ｃ−ＮＭＲ（ＣＤＣｌ_３，δｐｐｍ）：２９．２８，３０．０２，３８．７４，３９．９５，４８．９９，５６．０５，１２３．２０，１２４．５７，１２９．２９，１４６．３８，１６１．６９
【００４７】
次いで、残りの溶液を１００℃まで昇温し、７時間加熱した。反応液を冷却後、不溶物を濾別してモノクロロベンゼンの溶液を得た。高速液体クロマトグラフィー（ＨＰＬＣ）により分析を行ったところ、２，５−ビス（イソシアナトメチル）−１，４−ジチアン（ＢＩＭＤ）を３．２２ｇ含有していた（収率７０％）。
【００４８】
（実施例２）
モノクロロベンゼン（１５０ｍｌ）を５℃に冷却し、ホスゲンガス２２．４ｇ（０．２３ｍｏｌ）を吹き込んだ。そこへ、ＴＢＭＤ６．３１ｇ（純度９２％、０．０２ｍｏｌ）をモノクロロベンゼン（２０ｍｌ）に溶解した溶液を滴下し、５〜５０℃で８．５時間攪拌した。その後、１００℃に昇温し、４時間加熱し、冷却後不溶物をろ過により除去し、モノクロロベンゼンの溶液を得た。ＨＰＬＣにより分析したところ、ＢＩＭＤを２．３０ｇ含有していた（収率５０％）。
【００４９】
（実施例３）
ＴＢＭＤ１５．７９ｇ（純度９２％、０．０５ｍｏｌ）をモノクロロベンゼン（１８０ｍｌ）に溶解した後、１００℃まで加熱した。そこへ塩酸ガス５．５ｇ（０．１５ｍｏｌ）を吹き込んで塩酸塩とし、さらに１２０℃に昇温した後、ホスゲンガス６４．４ｇ（０．６５ｍｏｌ）を吹き込み１２０〜１３０℃で４．５時間攪拌した。冷却後不溶物をろ過により除去しモノクロロベンゼンの溶液を得た。これをＨＰＬＣにより分析したところ、ＢＩＭＤを３．４５ｇ含有していた（収率３０％）。
【００５０】
【発明の効果】
以上述べたように、本発明によれば、目的とする２，５−ビス（イソシアナトメチル）−１，４−ジチアン類を効率よく製造することができる。また本発明の製造方法によれば、目的物を簡便な後処理操作により効率よく単離することができるので、工業的製造方法として優れているといえる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane useful as a raw material for producing a high refractive index polymer, and a method for producing 2,5-bis (isocyanatomethyl) -1,4. The present invention relates to an intermediate for producing dithiane and a method for producing the same.
[0002]
[Prior art]
2,5-bis (isocyanatomethyl) -1,4-dithiane (the compound in which R is a hydrogen atom in the formula (I)) is a raw material for producing a high refractive index polymer useful as a lens resin material. Conventionally, as a method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane, 2,5-bis (chloromethyl) -1,4-dithiane is usually used in the presence or absence of a catalyst. There is known a method in which an amino compound is obtained by reacting with ammonia water or ammonia gas under pressure or pressurization conditions, then hydrochlorinated with hydrochloric acid gas at a high temperature, and further reacted with phosgene (Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-130263
[Problems to be solved by the invention]
However, in the above method, (i) a large amount of ammonia is used under pressure, and a special reaction tank for a pressurized reaction is required. (Ii) When the reaction is carried out at normal pressure, Since a large amount of water is required to dissolve a large amount of ammonia, the production efficiency is deteriorated. (Iii) Furthermore, 2,5-bis (aminomethyl) -1,4-dithiane has high water solubility, There is a problem that a large amount of water needs to be distilled off in the post-treatment in order to efficiently remove this substance.
[0005]
The present invention has been made in view of the problems of the related art, and has no problems such as post-treatment, and a method for efficiently producing 2,5-bis (isocyanatomethyl) -1,4-dithianes; An object of the present invention is to provide an intermediate for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane and a method for producing the intermediate.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, an amino compound or its hydrochloride which can be easily obtained from a 2,5-bis (halogenomethyl) -1,4-dithiane compound and a tertiary amine with phosgene. It has been found that the desired compound can be obtained in good yield by chlorocarbonylation and pyrolysis of the obtained compound, and the present invention has been completed.
[0007]
Thus, according to a first aspect of the present invention, there is provided a compound of formula (II)
[0008]
Embedded image

[0009]
(Wherein R ¹ , R ² and R ³ each independently represent a C1 to C6 alkyl group or an aryl group, and R represents a hydrogen atom or a C1 to C6 alkyl group). Formula (I) characterized in that:
[0010]
Embedded image

[0011]
(Wherein, R represents the same meaning as described above). A process for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane represented by the formula:
The method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane of the present invention is represented by the formula (III)
[0012]
Embedded image

[0013]
(Wherein R, R ¹ , R ² and R ³ have the same meanings as described above), and phosgene is reacted with the compound represented by the formula (II).
[0014]
Embedded image

(Wherein R, R ¹ , R ² and R ³ have the same meanings as described above), and then heating the resulting compound represented by the formula (II). Preferably it is.
[0015]
According to a second aspect of the invention, formula (II)
[0016]
Embedded image

[0017]
(Wherein, R, R ¹ , R ² and R ³ have the same meanings as described above). This is an intermediate for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane according to the present invention.
According to a third aspect of the invention, formula (III)
[0018]
Embedded image

[0019]
Wherein R, R ¹ , R ² and R ³ have the same meanings as described above, and phosgene is reacted with a compound represented by the formula (II):
[0020]
Embedded image

[0021]
Wherein R, R ¹ , R ² and R ³ have the same meanings as described above.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
The outline of the method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane of the present invention is shown below.
[0023]
Embedded image

[0024]
The compound represented by the formula (II) used in the production method of the present invention is a novel compound.
In the formula (II), R represents a hydrogen atom or a C1-C6 alkyl group. Specific examples of the C1 to C6 alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like. Is mentioned.
[0025]
R ¹ , R ² and R ³ each independently represent a C1 to C6 alkyl group or an aryl group. Specific examples of the C1 to C6 alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like. And specific examples of the aryl group include a phenyl group and a p-methoxyphenyl group.
Specific examples of the compound represented by the formula (II) include those shown in Table 1 below.
[0026]
[Table 1]

[0027]
The compound represented by the formula (II) can be obtained by reacting the amine compound represented by the formula (III) or a salt thereof with phosgene.
[0028]
As a method of performing this reaction, for example, a method of adding phosgene to a solution containing an amine compound represented by the formula (III) or a salt thereof, or a method of dissolving an amine represented by the formula (III) in a solution in which phosgene is dissolved A method of adding a compound or a salt thereof or a solution thereof may be mentioned.
[0029]
The above reaction can be carried out in a suitable solvent. The solvent used is not particularly limited as long as it is inert to the reaction. For example, aromatic hydrocarbons such as chlorobenzene, toluene, xylene, nitrobenzene, benzotrifluoride and benzonitrile; halogenated hydrocarbons such as chloroform, 1,2-dichloroethane and methylene chloride; nitriles such as acetonitrile and propionitrile Ethers such as tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate and isopropyl acetate;
[0030]
The reaction is preferably performed in a temperature range of -5 ° C to + 100 ° C, more preferably in a range of 5 ° C to 20 ° C.
The amount of phosgene used is not particularly limited, but is usually in the range of 1 to 20 mol, preferably 1.5 to 10 mol, per 1 mol of the amine compound represented by the formula (III).
[0031]
In this reaction, the reaction can be carried out in the presence of a tertiary amine as a dehalogenating agent.
Specific examples of the tertiary amine include trimethylamine, triethylamine, tri-n-butylamine, N, N-dimethylcyclohexylamine, N, N-diethylaniline, pyridine, quinoline, and N, N-dimethylaminopyridine.
[0032]
The use amount of the tertiary amine is preferably in the range of 1.0 to 1.5 mol per 1 mol of the amine compound represented by the formula (III). When a salt of the compound represented by the formula (III) is used, it is necessary to further add an amount necessary for neutralizing the salt.
When a tertiary amine is used, the tertiary amine may be added to the solution of the amine compound represented by the formula (III) before adding phosgene, or may be added after adding phosgene.
[0033]
Since the compound represented by the formula (II) itself is unstable, it is preferable that the compound is directly subjected to the next step without isolation and purification after the reaction. Further, a part or all of the solvent can be replaced and then used in the next step.
When a tertiary amine is used as a dechlorinating agent, the resulting salt may be washed with water or removed by filtration, and then used as it is, or may be partially or entirely substituted for the solvent for the next step. it can.
[0034]
The compound represented by the formula (II) is reacted with a compound represented by the formula (II) and a primary or secondary amine to induce a stable urea form, whereby the compound represented by the formula (II) is obtained. The formation of the compound can be confirmed.
[0035]
In the amine compound represented by the formula (III) used for the production of the compound represented by the formula (II), R, R ¹ , R ² and R ³ have the same meanings as described above, and exemplify the same specific examples. can do.
The amine compound represented by the formula (III) can be easily produced from the corresponding halogen compound and the corresponding amine.
Further, the salt of the amine compound represented by the formula (III) can be easily produced, for example, by reacting the amine compound with hydrochloric acid gas.
[0036]
The present invention is characterized in that a compound represented by the formula (II) is pyrolyzed to produce an isocyanate represented by the formula (I).
[0037]
As a method of thermally decomposing the compound represented by the formula (II), specifically, a method of heating the compound represented by the formula (II) in a solvent can be exemplified.
[0038]
As the solvent to be used, aromatic hydrocarbons such as chlorobenzene, toluene, xylene, nitrobenzene, benzotrifluoride and benzonitrile; halogenated hydrocarbons such as chloroform, 1,2-dichloroethane and methylene chloride; acetonitrile and propionitrile Nitriles; ethers such as tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate and isopropyl acetate;
[0039]
The reaction proceeds simply by heating, but when the reaction system is acidic due to decomposition of phosgene or the like, the presence of the acid hinders the reaction, and therefore an organic base such as triethylamine or tri-n-butylamine is used. It is preferable to add tertiary amines, pyridines and the like to the reaction system.
[0040]
The reaction proceeds at the boiling point of the solvent, but is preferably performed at 100 ° C. or higher. Further, a Lewis acid such as ferric chloride can be added as a catalyst.
[0041]
In the present invention, the amine compound represented by the formula (III) is hydrochlorinated by blowing hydrochloric acid gas or the like as necessary, and then blowing phosgene gas and heating, or blowing phosgene gas while heating, By continuously performing phosgenation and thermal decomposition, the desired isocyanate represented by the formula (I) can also be obtained.
[0042]
A polymer obtained by polymerizing 2,5-bis (isocyanatomethyl) -1,4-dithiane obtained by the production method of the present invention has excellent transparency and a high refractive index, and has a property of a lens resin. Useful as a material.
[0043]
【Example】
Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.
(Example 1)
After dissolving 6.31 g (purity 92%, 0.02 mol) of 2,5-bis (t-butylaminomethyl) -1,4-dithiane (TBMD) in monochlorobenzene (170 ml), 4.44 g of triethylamine ( 0.044 mol) and cooled to 5 ° C. After cooling, 21.3 g (0.22 mol) of phosgene gas was blown, and the mixture was stirred for 6 hours to synthesize 2,5-bis (t-butyl-chlorocarbonylaminomethyl) -1,4-dithiane (BCMD).
A part of the reaction solution was taken, N-methylaniline was added in a large excess, and the resulting urea compound was isolated and purified by column chromatography. By measuring the NMR spectrum (nuclear magnetic resonance spectrum) of the obtained urea derivative, it was confirmed that the obtained urea derivative was the compound shown below.
[0044]
Embedded image

[0045]
¹ H-NMR (CDCl ₃ , δ ppm): 1.43 (18H, S), 2.5 to 3.2 (10H, m), 3.20 (6H, s), 7.11 to 7.17 ( 6H, m), 7.30 to 7.38 (4H, m)
[0046]
_{^{13 C-NMR (CDCl 3,}} δppm): 29.28,30.02,38.74,39.95,48.99,56.05,123.20,124.57,129.29,146.38 , 161.69
[0047]
Then, the remaining solution was heated to 100 ° C. and heated for 7 hours. After cooling the reaction solution, insolubles were removed by filtration to obtain a monochlorobenzene solution. Analysis by high performance liquid chromatography (HPLC) showed that 3.22 g of 2,5-bis (isocyanatomethyl) -1,4-dithiane (BIMD) was contained (yield 70%).
[0048]
(Example 2)
Monochlorobenzene (150 ml) was cooled to 5 ° C., and 22.4 g (0.23 mol) of phosgene gas was blown. A solution of 6.31 g (purity 92%, 0.02 mol) of TBMD dissolved in monochlorobenzene (20 ml) was added dropwise thereto, and the mixture was stirred at 5 to 50 ° C. for 8.5 hours. Thereafter, the temperature was raised to 100 ° C., and the mixture was heated for 4 hours. After cooling, insolubles were removed by filtration to obtain a monochlorobenzene solution. As a result of analysis by HPLC, it contained 2.30 g of BIMD (yield 50%).
[0049]
(Example 3)
After dissolving 15.79 g of TBMD (purity 92%, 0.05 mol) in monochlorobenzene (180 ml), the mixture was heated to 100 ° C. 5.5 g (0.15 mol) of hydrochloric acid gas was blown into the hydrochloride to form a hydrochloride, and after the temperature was further raised to 120 ° C., 64.4 g (0.65 mol) of phosgene gas was blown, and the mixture was stirred at 120 to 130 ° C. for 4.5 hours. . After cooling, insolubles were removed by filtration to obtain a monochlorobenzene solution. When this was analyzed by HPLC, it contained 3.45 g of BIMD (yield 30%).
[0050]
【The invention's effect】
As described above, according to the present invention, the desired 2,5-bis (isocyanatomethyl) -1,4-dithiane can be efficiently produced. Further, according to the production method of the present invention, the target product can be efficiently isolated by a simple post-treatment operation, and thus it can be said that the method is excellent as an industrial production method.

Claims (4)

Formula (II)

(Wherein R ¹ , R ² and R ³ each independently represent a C1 to C6 alkyl group or an aryl group, and R represents a hydrogen atom or a C1 to C6 alkyl group). Formula (I) characterized in that:

(Wherein, R represents the same meaning as described above.) A method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane represented by the formula: Formula (III)

(Wherein R, R ¹ , R ² and R ³ have the same meanings as described above), and phosgene is reacted with the compound represented by the formula (II).

(Wherein R, R ¹ , R ² and R ³ have the same meanings as described above), and then heating the obtained compound represented by the formula (II). A method for producing 2,5-bis (isocyanatomethyl) -1,4-dithiane represented by the formula (I), which is characterized by the following. Formula (II)

(Wherein, R, R ¹ , R ² and R ³ represent the same meaning as described above). Formula (III)

Wherein R, R ¹ , R ² and R ³ have the same meanings as described above, and phosgene is reacted with a compound represented by the formula (II):

(Wherein, R, R ¹ , R ² and R ³ represent the same meaning as described above).