JP3898011B2 - Method for producing aromatic fluorine compound - Google Patents

Description

【００１３】
（式中、Ｃｌは塩素原子を示し、−Ｘは−ＣＮ、−ＮＯ₂、−ＣＯＦまたは−ＣＯＣｌのいずれかを示し、ａはＸの置換数を示し０、１または２のいずれかであり、ｂは塩素原子の置換数を示しｂ≧１であり、ａ＋ｂ≦６である。Ｘが複数存在する場合には、各Ｘは同一でも異なっていてもよい。）
【００１４】
【化２】

【００１５】
（式中、Ｃｌは塩素原子を示し、−Ｚ−は、−Ｏ−または＞ＮＲ（ここで、Ｒは水素原子、炭素数１〜６のアルキル基、またはアリール基である。）を示し、ａは塩素原子の置換数を示し、１≦ａ≦４の整数である。）
上記、一般式（１）または（２）で示される化合物の代表例としては、モノクロロベンゼン、ジクロロベンゼン、トリクロロベンゼン、テトラクロロベンゼン、ペンタクロロベンゼン、ヘキサクロロベンゼン、２，６−ジクロロベンゾニトリル、２，４，６−トリクロロベンゾニトリル、ペンタクロロベンゾニトリル、３，４，５，６−テトラクロロフタロニトリル、テトラクロロ無水フタル酸、テトラクロロフタル酸ジフルオライド、テトラクロロ無水フタル酸アミド、Ｎ−アルキルテトラクロロ無水フタル酸アミド（アルキル基：メチル、エチル、ｎ−プロピル、イソプロピル、ｎ−ブチル、イソブチルなど）、Ｎ−フェニルテトラクロロ無水フタル酸アミド、２，３，４−トリクロロニトロベンゼン、ペンタクロロニトロベンゼンなどを挙げることができる。なかでも、３，４，５，６−テトラクロロフタロニトリル、ペンタクロロベンゾニトリルまたは２，６−ジクロロベンゾニトリルが好適に用いられる。
【００１６】
ハロゲン交換反応は、有機溶媒の存在下で行っても、あるいは不存在下に行ってもよい。有機溶媒としては、一般的にはジメチルスルホキシド（ＤＭＳＯ）、スルホラン（ＴＭＳＯ₂）、Ｎ，Ｎ−ジメチルスルホキシド（ＤＭＦ）、Ｎ−メチル−２−ピロリドン（ＮＭＰ）、ジメチルスルホン（ＤＭＳＯ₂）などのいわゆる非プロトン性極性溶媒、あるいはベンゾニトリルが用いられるが、反応性および熱安定性の点で、ベンゾニトリルが特に好適に用いられる。
【００１７】
また、フッ素化剤としては、芳香族塩素化合物とのハロゲン（フッ素）交換反応に使用し得るものであればいずれでもよいが、フッ化ナトリウム、フッ化カリウム、フッ化セシウムなどのアルカリ金属フッ化物が好ましく、フッ化カリウムが特に好適に用いられる。フッ素化剤の使用量は、フッ素原子によって置換される原料化合物の芳香族塩素化合物に含まれる塩素原子に対し、少なくとも同モル以上である必要があり、一般には塩素原子１個に対して１．０〜１．５個のフッ素原子となるようにフッ素化剤を使用する。
【００１８】
ハロゲン交換反応の方法については特に制限はなく、この種の反応に一般に用いられている方法にしたがって行うことができる。例えば、特公平２−１６７４６号公報に記載のように無溶媒で行っても、特公昭６２−７１８５号公報に記載のように、蒸留塔塔底から得られる未反応混合物を含む有機溶媒を循環しながら反応を行っても、あるいは特公平４−４３０９号公報に記載のように、ベンゾニトリル溶媒中に原料化合物を添加し、これを温度１９０〜４００℃の範囲で自然発生圧下、あるいは常圧下、還流しながら反応を行ってもよい。一般には、ＳＵＳ３１６などの耐薬品性の素材を使用し、撹拌翼を配設した耐圧性反応器内で、原材料を撹拌しつつ反応させる。
【００１９】
本発明の方法は、無溶媒で、より好ましくは非プロトン性極性溶媒またはベンゾニトリルなどの溶媒中で、２，６−ジクロロベンゾニトリル、テトラクロロフタロニトリルまたはペンタクロロベンゾニトリルをフッ素化剤とハロゲン交換反応を行い、得られる反応物を反応器から抜き出す際に好適に用いられる。
【００２０】
本発明のハロゲン交換反応によって得られる反応物中には、目的物としての芳香族フッ素化合物のほかに、反応によって生成する塩化カリウムなどの無機塩も含まれているので、反応物は粘度が高く、また場合によってはチキソトロピー性を有することもあり、反応器から円滑に抜き出すのが困難な場合が多い。しかしながら、本発明の方法によれば、上記のような反応物を短時間で、かつ残留物を残さないようにして反応器から抜き出すことができる。
【００２１】
すなわち、本発明の特徴は上記反応物を、２０〜２５０℃の温度にて反応器から抜き出す点にある。製造目的物である芳香族フッ素化合物は、通常、ハロゲン交換反応終了後、次工程に移行して目的物を精製するには、反応物を静置し低温で処理することが一般的である。その場合、本反応において、副生する塩化カリウムや残存する余剰のフッ化カリウムが固化することがあり、その結果反応物を取り出す際に取り出し口に詰まり、抜き出しが困難になるという問題があった。このため従来は、反応器内に取り出し具を挿入し、内容物を掻き出したり、反応器への溶剤を投入するなどして、反応物のつまりを解消することを行なっていた。しかしながら、本発明では、反応物の抜き出し時の温度を２０〜２５０℃の範囲に調整することで、反応物の流動性が確保できることを見出し、反応物の抜き出しを極めて容易にすることができたのである。
【００２２】
本発明によれば、反応物を２０〜２５０℃、好ましくは５０〜２３０℃、より好ましくは１００〜２２０℃、特に好ましくは１５０〜２００℃の範囲の温度で反応器から抜き出す。２０℃より低い温度では、反応物の粘度が上昇し、円滑な抜き出しができなくなるばかりでなく、２０℃以下まで冷却するための時間が必要となって工業的には不適当である。また、２５０℃を超える温度にすると、抜き出し時の反応物の温度が高温であるために、目的物あるいは溶媒が、抜き出し容器側で蒸気化した状態となり、その結果これらのものが飛散し、その際、反応物中に存在する無機塩などが同伴されてしまい、装置を汚損するなど工業的に不適当である。
【００２３】
本発明では、反応物を撹拌しつつ上記２０〜２５０℃の温度範囲に調整することで、さらに優れた反応物の流動性が確保できるのである。特に本発明の目的物である芳香族フッ素化合物は、無機化合物に属するフッ素化剤を使用するため、反応時にはフッ素化剤との反応性を確保するため反応物を単位容積当たりの撹拌動力０．１〜１０ｋｗ／ｍ³、より好ましくは０．５〜７．０ｋｗ／ｍ³、特には１．０〜４．０ｋｗ／ｍ³で撹拌することが一般的である。従来は、反応終了後に撹拌を停止していたが、本発明では、上記温度制御と共に撹拌を継続することで、反応物の流動性を確保する。この温度制御の際の撹拌動力は、反応時の撹拌動力と同じであっても異なっていてもよく、反応物の単位容積あたり０．１〜１０ｋｗ／ｍ³、より好ましくは０．５〜７．０ｋｗ／ｍ³、特には１．０〜４．０ｋｗ／ｍ³の撹拌動力である。また、反応物を反応器から取り出す際の撹拌動力は、反応物の単位容量当たりの機動力として０．０１〜３．０ｋｗ／ｍ³であることが好ましく、より好ましくは０．０５〜２．５ｋｗ／ｍ³、特には０．１〜２ｋｗ／ｍ³である。この範囲で、反応物中に溶媒が含まれるか否か、使用するフッ素化剤の配合量などに係わらず、反応器からの取り出しに適する反応物の流動性が確保できるからである。また、温度調整時に限らず、取り出し時にも撹拌翼を回転させて反応物を取り出してもよい。
【００２４】
なお、本発明における抜き出し時の反応物の単位容積当たりの撹拌動力とは、抜き出し前後の撹拌機の電流値から所要撹拌動力を算出し、その差から所要撹拌動力を得て、これを反応物の容積で除して算出したものである。
すなわち、反応時または反応物の冷却時（抜き出し前）の撹拌動力（Ａ）は交流を使用する場合、√３×電圧×電流値１×力率１／１０００で示され、反応物抜き出し採集時（抜き出し後）の撹拌動力（Ｂ）は、√３×電圧×電流値２×力率２／１０００で示されるため、抜き出し時の単位容積当たりの撹拌動力は、（（Ａ）−（Ｂ））／反応物の容積となる。この数値が示すように、抜き出し時の撹拌動力とは、反応物の抜き出し経過時間の平均撹拌動力を示す。
【００２５】
この際、反応物の抜き出しを加圧下に行ない、または反応物の抜き出しを、反応物を吸引下に行なうことでより円滑に作業することができる。具体的には、反応器の内部圧力を外部圧力より高くすることにより、例えば、反応器とこれに接続された反応物導入容器とからなる装置の場合、反応器の内部圧力を反応物導入容器の内部圧力よりも高くすることにより、反応物を反応器から効率よく抜き出すことができる。また、加圧下における反応物の抜き出しと、吸引下における反応物の抜き出しを併用してもかまわない。
【００２６】
反応器の内部圧力を外部圧力より高くするには種々の方法によって行うことができる。例えば、反応物を抜き出す時に反応器にガスを圧入するか、あるいは反応器に接続された反応物導入容器の内部圧力をポンプを用いて減圧させるなどすればよい。この減圧の程度は、反応物の粘度によって相違するが、ＢＬ型粘度計（株式会社トキメック製）による反応物の粘度が２〜２００ｃｐｓである場合には、反応器側の圧力が、ゲージ圧力で０．０１〜２ＭＰａ、好ましくは０．０５〜１ＭＰａ、更に好ましくは０．１〜０．５ＭＰａとして、反応物導入容器の内部圧力より高くなるようにすればよい。上記圧力差を発生させる場合、操作が比較的簡便で、しかも０．１ＭＰａ以上の圧力差を発生し得るという点で、反応器にガスを導入する方法が好適に用いられる。
【００２７】
使用するガスについては、反応物に対する悪影響がなく、工業的に安全に使用できるものであればいずれでもよく、例えば、窒素、炭酸ガス、ヘリウム、アルゴンなどの不活性ガス、あるいは空気、もしくは酸素濃度を低下させた空気などが用いられるが、特に窒素が、反応物に悪影響がなく、安全で、工業的に容易に入手可能でるという理由から窒素が好ましく用いられる。
【００２８】
反応物を抜き出す際の抜き出し方法としては、例えば、反応器内部を窒素などの不活性ガスで加圧状態にして、反応物を攪拌しながら、あるいは攪拌することなく抜き出す方法の他、反応器の内部圧力は大気圧として、反応物導入容器の内部をポンプなどで減圧状態にした後、反応物を攪拌しながら、あるいは攪拌することなく抜き出す方法を挙げることができる。より円滑に、かつ効率的に抜き出せるという理由から、攪拌して抜き出すほうが好ましい。また、反応器内部を加圧状態にする窒素などの不活性ガスは、抜き出すときに、抜き出し状態あるいは反応器内部圧力を観察しながら、適宜、反応器内部に供給して抜き出しが円滑に行えるようにするのがよい。なお、反応器内物に少量の反応物が残存した場合には、反応器内部に溶剤などを投入、攪拌して良好なスラリー状態とした後、抜き出してもよい。
【００２９】
本発明の方法では、原料化合物である芳香族塩素化合物とフッ素化剤との未反応物に加え、反応の副生物である塩化カリウムまたは残存する未反応フッ素化剤等の無機塩が不溶物として反応物中に残存するため、反応物の粘度が高い。特に、芳香族塩素化合物に含まれる塩素原子数が多い場合には、使用するフッ素化剤の使用量も多くなり、その結果反応物に残存する副生物である塩化カリウムまたは残存する未反応フッ素化剤量も多くなるため、反応物の粘度が高くなる。このような観点から、本発明の製造方法は、３，４，５，６−テトラクロロフタロニトリル、ペンタクロロベンゾニトリル等のように１化合物中に４または５個の塩素原子を含む芳香族塩素化合物を原料化合物とする場合に特に有効である。また、２，６−ジクロロベンゾニトリルなどを原料とする場合には、含まれる塩素原子数は少なくても無溶媒下でフッ素化剤と反応させる場合があり、結果として反応物の粘度が高くなる。従って、２，６−ジクロロベンゾニトリルを原料化合物とする場合、無溶媒下にハロゲン化反応を行なう場合にも、本発明によって好適に反応物を取り出すことができる。
【００３０】
【実施例】
以下、実施例を挙げて本発明を更に具体的に説明する。
【００３１】
（参考例１）
３００Ｌのステンレス鋼製オートクレーブにベンゾニトリル１５０ｋｇ、ペンタクロロベンゾニトリル５２ｋｇ（０．１８９１キロモル）およびスプレードライフッ化カリウム６０ｋｇ（１．０３３キロモル）を仕込み、オートクレーブ内の空気を窒素で置換した後、撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ３４０℃で１８時間反応を行った。
【００３２】
反応終了後、反応液をガスクロマトグラフィー分析したところ、反応液中には目的物であるペンタフルオロベンゾニトリル３１．１ｋｇ（０．１６１２キロモル、収率８５．４モル％）と有効成分である３，５−ジクロロ−２，４，６−トリフルオロベンゾニトリル８．２ｋｇ（０．０３９１キロモル）とが含まれていた。
【００３３】
（実施例１）
３００Ｌのステンレス鋼製オートクレーブにベンゾニトリル１５０ｋｇ、ペンタクロロベンゾニトリル５２ｋｇ（０．１８９１キロモル）およびスプレードライフッ化カリウム６０ｋｇ（１．０３３キロモル）を仕込み、オートクレーブ内の空気を窒素で置換した後、撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ３４０℃で１８時間反応を行った。
【００３４】
反応終了後、反応液を撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ１５０℃まで冷却し、窒素ガスで反応器内部圧力を０．３ＭＰａに加圧し、攪拌しつつ、反応器下部のバルブを解放して、反応物を反応器下部のバルブに接続したブレンダーに抜き出した。抜き出し前後の撹拌機駆動部の電流量から算出した抜き出し時の反応物の単位容積当たりの撹拌動力は、０．４ｋｗ／ｍ³であった。抜き出しに要した時間は５分であった。
【００３５】
また、抜き出した反応物のガスクロマトグラフィー分析を行った結果、抜き出し液中には目的物であるペンタフルオロベンゾニトリル３０．８ｋｇ（０．１５９６キロモル、収率８５．０モル％）と有効成分である３，５−ジクロロ−２，４，６−トリフルオロベンゾニトリル８．１ｋｇ（０．０３５８キロモル）とが含まれており、反応器内部を観察したところ、内部には反応物がほとんど残存していなかった。回収率（参考例１での収率を基準にした抜き出し後の回収率；以下同じ。）は９９％であった。
【００３６】
（実施例２）
３００Ｌのステンレス鋼製オートクレーブにベンゾニトリル１５０ｋｇ、テトラクロロフタロニトリル５２ｋｇ（０．１９５５キロモル）およびスプレードライフッ化カリウム５０ｋｇ（０．８６０１キロモル）を仕込み、オートクレーブ内の空気を窒素で置換した後、撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ２５５℃で２０時間反応を行った。
【００３７】
反応終了後、反応液を撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ１５０℃まで冷却し、窒素ガスで反応器内部圧力を０．３ＭＰａに加圧し、攪拌しつつ反応器下部のバルブを解放して、反応物を反応器下部のバルブに接続したブレンダーに抜き出した。抜き出し前後の撹拌機駆動部の電流量から算出した抜き出し時の反応物の単位容積当たりの撹拌動力は、０．４５ｋｗ／ｍ³であった。抜き出しに要した時間は４分であった。また、抜き出した反応物のガスクロマトグラフィー分析を行った結果、反応物中には目的物であるテトラフルオロフタロニトリル３５．２ｋｇ（０．１７６０キロモル、収率９０．０モル％）と有効成分である３−クロロ−４，５，６−トリフルオロフタロニトリル２．５４ｋｇ（０．０１１７キロモル）とが含まれており、反応器内部を観察したところ、内部には反応物がほとんど残存していなかった。回収率は９９％であった。
【００３８】
（実施例３）
３００Ｌのステンレス鋼製オートクレーブにジメチルスルホキシド１５０ｋｇ、２，６−ジクロロベンゾニトリル５２ｋｇ（０．３０２３キロモル）およびスプレードライフッ化カリウム３８．６ｋｇ（０．６６５１キロモル）を仕込み、オートクレーブ内の空気を窒素で置換した後、撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ１６０℃で１２時間反応を行った。
【００３９】
反応終了後、反応液を撹拌動力１．０〜３．０ｋｗ／ｍ³で攪拌しつつ１５０℃まで冷却し、窒素ガスで反応器内部圧力を０．２ＭＰａに加圧し、攪拌しつつ反応器下部のバルブを解放して、反応物を反応器下部のバルブに接続したブレンダーに抜き出した。抜き出し前後の撹拌機駆動部の電流量から算出した抜き出し時の反応物の単位容積当たりの撹拌動力は、０．３８ｋｗ／ｍ³であった。抜き出しに要した時間は４分であった。また、抜き出した反応物のガスクロマトグラフィー分析を行った結果、反応物中には目的物である２，６−ジフルオロベンゾニトリル３８．８ｋｇ（０．２７９０キロモル、収率９２．３モル％）と有効成分である２−クロロ−６−フルオロベンゾニトリル２．１２ｋｇ（０．０１３６キロモル）とが含まれており、反応器内部を観察したところ、内部には反応物がほとんど残存していなかった。回収率は９９％であった。
【００４０】
（実施例４）
実施例１において、抜き出し時の反応物の温度を１００℃とした以外は、実施例１と同様にして反応物を抜き出したところ、抜き出しに要した時間は７分であった。回収率は９８．５％であった。
【００４１】
（実施例５）
実施例１において、抜き出し時の反応器内部圧力を０．５ＭＰａとした以外は、実施例１と同様にして反応物を抜き出したところ、抜き出しに要した時間は３分であった。回収率は９９．５％であった。
【００４２】
（実施例６）
実施例１において、抜き出し時の反応物の温度を１５０℃とし、抜き出し容器側の圧力をポンプを使用して０．０１３ＭＰａとした以外は、実施例１と同様にして反応物を抜き出したところ、抜き出しに要した時間は６分であった。回収率は９９．０％であった。
【００４３】
（比較例１）
実施例１において、抜き出し時の反応物の温度を１０℃とした以外は、実施例１と同様にして反応物を抜き出したところ、抜き出しに要した時間は６０分であった。回収率は７０．０％であった。
【００４４】
（比較例２）
実施例１において、抜き出し時の反応物の温度を２８０℃とした以外は、実施例１と同様にして反応物を抜き出したところ、抜き出しに要した時間は３分であった。回収率は８０％であった。
【００４５】
（実施例７）
容量３００リットルのステンレス鋼製オートクレーブにベンゾニトリル１５０ｋｇ、ペンタクロロベンゾニトリル５０ｋｇ、およびスプレードライフッ化カリウム５８ｋｇを仕込み、オートクレーブ内の空気を窒素で置換した後、撹拌動力２．０〜４．０ｋｗ／ｍ³で攪拌しつつ３４０℃に昇温し、この温度で、１８時間反応を行なった。反応終了後、反応液を撹拌動力２．０〜４．０ｋｗ／ｍ³で攪拌しつつ１９０℃まで冷却し、窒素ガスで反応器内部圧力を０．３ＭＰａに加圧し、撹拌しつつ反応器下部のバルブを解放して、反応物を反応器下部のバルブに接続したブレンダーに抜出した。抜き出し前後の撹拌機駆動部の電流量から算出した抜き出し時の反応物の単位容積当たりの撹拌動力は、０．５ｋｗ／ｍ³であった。抜出しに要した時間は、１分であった。また、抜出した反応物のガスクロマトグラフィー分析を行なった結果、抜出し液中には目的物であるペンタフルオロベンゾニトリル３２．８ｋｇ（収率 ９３．７モル％）と有効成分である３−クロロ−２，４，５，６−テトラフルオロベンゾニトリル １．９ｋｇおよび３，５，−ジクロロ−２，４，６−トリフルオロベンゾニトリル ０．４ｋｇとが含まれていた。反応器内部を観察したところ、内部には、反応物が、ほとんど残存していなかった。回収率は、９９．８％であった。
【００４６】
（実施例８）
実施例７において、抜出し温度を２３０℃とした以外は、同様の方法で抜出したところ、抜出しに要した時間は、ほぼ同様で８分であり、回収率は９５％であった。
【００４７】
（実施例９）
実施例７において、抜出し温度を５０℃とした以外は、同様の方法で抜出したところ、抜出しに要した時間は、７分であった。また、回収率は、９６％であった。
【００４８】
（実施例１０）
撹拌機および凝縮器を備えた容量３００リットルのグラスライニング製反応器に、スルフォラン１５０ｋｇ、Ｎ−メチル−テトラクロロフタルミド５８ｋｇ（０．１９４モル）、およびスプレードライフッ化カリウム５０ｇを仕込み、反応器内部の空気を窒素で置換した後、撹拌動力２．０〜４．０ｋｗ／ｍ³で攪拌しつつ２２０℃に昇温し、この温度で、５時間反応を行なった。反応終了後、反応液を撹拌動力２．０〜４．０ｋｗ／ｍ³で攪拌しつつ１９０℃まで冷却し、窒素ガスで反応器内部圧力を０．０５ＭＰａに加圧し、反応液を撹拌しつつ反応器下部のバルブを解放して、反応物を反応器下部のバルブから抜出した。抜き出し前後の撹拌機駆動部の電流量から算出した抜き出し時の反応物の単位容積当たりの撹拌動力は、０．４８ｋｗ／ｍ³であった。抜出しに要した時間は、２分であった。抜出した反応物のガスクロマトグラフィー分析を行なった結果、抜出し液中には目的物であるＮ−メチル−テトラフルオロフタルイミド３７ｋｇ（０．１５８９モル、収率 ８１．９モル％）が含まれており、内部には、反応物が、ほとんど残存していなかった。回収率は、９９．３％であった。
【００４９】
（実施例１１）
実施例２において、反応液の抜出し時の温度を１８０℃とした以外は、同様の方法で抜出したところ、抜出しに要した時間は、２分であった。また、回収率は、９９．６モル％であった。
【００５０】
（比較例３）
実施例７において、反応終了後、撹拌を停止し、反応液の抜き出し時の温度を２６０℃とした以外は、同様の方法で抜き出したところ、反応生成物を一部しか取り出すことができず、回収率は５０％であった。
【００５１】
（比較例４）
実施例７において、反応終了後、撹拌を停止し、反応液の抜き出し時の温度を１５℃とした以外は、同様の方法で抜き出したところ、反応生成物は、ほとんど取り出すことができ無かった。
【００５２】
【発明の効果】
本発明によれば、ハロゲン交換反応後の反応物を反応器から短時間で、しかも残留物がないように、効率よく抜き出すことができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an aromatic fluorine compound, and more specifically, a reactant containing an aromatic fluorine compound, which is obtained by subjecting an aromatic chlorine compound to a halogen exchange reaction with a fluorinating agent, is efficiently extracted from the reactor. Regarding the method.
[0002]
[Prior art]
A method for producing an aromatic fluorine compound by subjecting an aromatic fluorine compound to a halogen exchange reaction with a fluorinating agent is generally known. For example, Japanese Examined Patent Publication No. 62-7185 describes a method of obtaining pentafluorobenzonitrile by subjecting pentachlorobenzonitrile in a benzonitrile to a halogen exchange reaction with a fluorinating agent. The reaction temperature is preferably 270 to 400 ° C. and the reaction time is preferably in the range of 2 to 48 hours. In the examples, benzonitrile, pentachlorobenzonitrile and dry potassium fluoride are charged in an autoclave, and the mixture is heated and stirred at 320 ° C. for 16 hours. To get the target. After completion of the reaction, a rotary evaporator is used to separate potassium chloride and unreacted potassium fluoride from the reaction solution at an external temperature of 200 ° C. to obtain a benzonitrile solution containing pentafluorobenzonitrile at the bottom of the kettle.
[0003]
Japanese Patent Publication No. 1-49346 discloses a method of obtaining tetrafluorophthalonitrile by subjecting tetrachlorophthalonitrile to a halogen exchange reaction with a fluorinating agent in benzonitrile. The reaction temperature is preferably 190 to 320 ° C. and the reaction time is preferably in the range of 2 to 48 hours. In the examples, benzonitrile, tetrachlorophthalonitrile and dry potassium fluoride are charged in an autoclave and heated and stirred at 255 ° C. for 16 hours. To get the target. After completion of the reaction, a rotary evaporator is used to separate potassium chloride and unreacted potassium fluoride from the reaction solution at an external temperature of 230 ° C., and then the separated solution is distilled to obtain benzonitrile and tetrafluorophthalonitrile. Yes.
[0004]
Japanese Patent Publication No. 2-16746 discloses a method in which the halogen exchange reaction is carried out in an aprotic polar solvent or without a solvent. The reaction temperature is preferably 200 to 450 ° C. and the reaction time is preferably 0.5 to 30 hours. In the examples, 2,6-dichlorobenzonitrile and potassium fluoride are charged into an autoclave and reacted at 350 ° C. for 3 hours. To get the target. After completion of the reaction, the temperature is lowered and the target product is obtained from a distillation apparatus at around 200 ° C.
[0005]
Japanese Patent Publication No. 4-4309 discloses that 3,4,5,6-tetrachlorophthalonitrile is refluxed in a benzonitrile solvent at a temperature in the range of 190 to 400 ° C. under a naturally occurring pressure or at normal pressure. The method of making it react is described. When benzonitrile is used at a boiling point or higher, the solubility of potassium fluoride increases rapidly. Therefore, the reaction temperature is in the range of 190 to 400 ° C., and the reaction time is preferably in the range of 2 to 48 hours. 4,5,6-tetrachlorophthalonitrile and dry potassium fluoride were charged and reacted at 230 ° C. for 10 hours to obtain the desired product. After completion of the reaction, the reaction mixture is cooled to room temperature, and suspended potassium chloride and unreacted potassium fluoride are removed by filtration to obtain 3,4,5,6-tetrafluorophthalonitrile as a target product in the mother liquor. ing. That is, in any of the methods described in the above publications, the raw material compound is charged into a reactor to synthesize the target product, which is then taken out of the reactor and purified by another container equipped with filtration and an evaporator. .
[0006]
[Problems to be solved by the invention]
However, fluorinating agents used for halogen exchange reaction of aromatic chlorine compounds with fluorinating agents are alkali metal fluoride salts such as cesium fluoride, potassium fluoride, sodium fluoride, barium fluoride, fluoride It is a fluoride salt of an alkaline earth metal such as calcium, and remains as a precipitate in the reaction solution after the halogen exchange reaction. Since the reaction product obtained by the halogen exchange reaction is generally a highly viscous slurry, there is a problem that the working time for extracting from the reactor is long and a part of the reaction product remains in the reactor. On the other hand, the raw material compound and the target product generally have a strong odor, and it is substantially difficult for an operator to collect the reaction product directly from the reaction vessel for reasons of occupational health. In particular, in the reaction process, hydrogen fluoride, which is a corrosive compound, may be produced as a by-product, and in a halogen exchange reaction that is usually carried out in a batch system, from the reaction vessel after the target product is produced, It is a very important problem to efficiently extract the reactant without leaking the odor and without exposing the operator to the reaction product atmosphere.
[0007]
For this reason, in the manufacturing field, development of the method of extracting a reaction material from a reactor in a short time so that it may not remain in a reactor was desired.
[0008]
[Means for Solving the Problems]
The above object is achieved by the following invention.
[0009]
  (1) In a method for producing an aromatic fluorine compound by subjecting an aromatic chlorine compound to a halogen exchange reaction with a fluorinating agent,Reactant obtained by halogen exchange reactionIn the reactor0.01-3.0kw / m ³ While stirring with stirring power per unit volume of the reactants of 50 to 230At temperatures in the range of ℃And under pressureA method for producing an aromatic fluorine compound, which is extracted from a reactor.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention provides a method for producing an aromatic fluorine compound by subjecting an aromatic chlorine compound to a halogen exchange reaction with a fluorinating agent,Reactant obtained by halogen exchange reactionIn the reactor0.01-3.0kw / m ³ While stirring with stirring power per unit volume of the reactants of 50 to 230At temperatures in the range of ℃And under pressureIt is a method for producing an aromatic fluorine compound, which is extracted from a reactor.
[0011]
The aromatic chlorine compound of the present invention is a compound containing at least one chlorine atom in an aromatic ring, and in addition to a chlorine atom, a substituent other than a chlorine atom, for example, an electron such as a cyano group, a nitro group, or a fluorocarbonyl group It means a compound which may have an attractive substituent. Specific examples include compounds represented by the following general formula (1) or (2).
[0012]
[Chemical 1]

[0013]
(Wherein Cl represents a chlorine atom, -X is -CN, -NO₂, -COF or -COCl, a represents the number of substitutions of X and is either 0, 1 or 2, b represents the number of substitutions of chlorine atoms, b≥1, and a + b≤6 is there. When two or more X exists, each X may be the same or different. )
[0014]
[Chemical formula 2]

[0015]
(Wherein Cl represents a chlorine atom, -Z- represents -O- or> NR (wherein R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group); a represents the number of substitution of chlorine atoms, and is an integer of 1 ≦ a ≦ 4.)
Typical examples of the compound represented by the general formula (1) or (2) include monochlorobenzene, dichlorobenzene, trichlorobenzene, tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, 2,6-dichlorobenzonitrile, 2,4. , 6-trichlorobenzonitrile, pentachlorobenzonitrile, 3,4,5,6-tetrachlorophthalonitrile, tetrachlorophthalic anhydride, tetrachlorophthalic acid difluoride, tetrachlorophthalic anhydride amide, N-alkyltetrachloroanhydride Phthalamide (alkyl groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc.), N-phenyltetrachlorophthalic anhydride, 2,3,4-trichloronitrobenzene, pentachloronitrobenzene, etc. It can be mentioned. Of these, 3,4,5,6-tetrachlorophthalonitrile, pentachlorobenzonitrile or 2,6-dichlorobenzonitrile is preferably used.
[0016]
The halogen exchange reaction may be carried out in the presence or absence of an organic solvent. As the organic solvent, dimethyl sulfoxide (DMSO), sulfolane (TMSO) is generally used.₂), N, N-dimethyl sulfoxide (DMF), N-methyl-2-pyrrolidone (NMP), dimethyl sulfone (DMSO)₂) Or so-called aprotic polar solvents, or benzonitrile is used, but benzonitrile is particularly preferably used from the viewpoint of reactivity and thermal stability.
[0017]
Any fluorinating agent may be used as long as it can be used for a halogen (fluorine) exchange reaction with an aromatic chlorine compound, but alkali metal fluorides such as sodium fluoride, potassium fluoride, and cesium fluoride. And potassium fluoride is particularly preferably used. The amount of the fluorinating agent is required to be at least the same mole or more with respect to the chlorine atoms contained in the aromatic chlorine compound of the raw material compound substituted by the fluorine atom. A fluorinating agent is used so as to obtain 0 to 1.5 fluorine atoms.
[0018]
There is no restriction | limiting in particular about the method of halogen exchange reaction, It can carry out according to the method generally used for this kind of reaction. For example, even if it is carried out without solvent as described in JP-B-2-16746, an organic solvent containing an unreacted mixture obtained from the bottom of the distillation tower is circulated as described in JP-B-62-2185. Even if the reaction is carried out, or as described in Japanese Patent Publication No. 4-4309, the raw material compound is added to the benzonitrile solvent, and this is subjected to a spontaneously generated pressure within a temperature range of 190 to 400 ° C. or under normal pressure. The reaction may be carried out while refluxing. In general, a chemical-resistant material such as SUS316 is used, and the raw materials are reacted while stirring in a pressure-resistant reactor provided with a stirring blade.
[0019]
The process of the present invention comprises 2,6-dichlorobenzonitrile, tetrachlorophthalonitrile or pentachlorobenzonitrile in a solvent-free, more preferably solvent such as an aprotic polar solvent or benzonitrile. It is preferably used when an exchange reaction is performed and the resulting reactant is withdrawn from the reactor.
[0020]
In the reaction product obtained by the halogen exchange reaction of the present invention, in addition to the target aromatic fluorine compound, inorganic salts such as potassium chloride produced by the reaction are also included, so the reaction product has a high viscosity. In some cases, it may have thixotropic properties, and it is often difficult to smoothly extract it from the reactor. However, according to the method of the present invention, the above reactants can be withdrawn from the reactor in a short time without leaving any residue.
[0021]
That is, the feature of the present invention is that the reactant is withdrawn from the reactor at a temperature of 20 to 250 ° C. In general, the aromatic fluorine compound which is the production target is generally treated at a low temperature by allowing the reaction to stand to proceed to the next step and purify the target after completion of the halogen exchange reaction. In this case, in this reaction, by-product potassium chloride or remaining excess potassium fluoride may solidify, and as a result, when the reaction product is taken out, there is a problem that the take-out port becomes clogged and it becomes difficult to take out. . For this reason, conventionally, removal of clogged reactants has been carried out by inserting a take-out tool into the reactor, scraping out the contents, or introducing a solvent into the reactor. However, in the present invention, it was found that the fluidity of the reactant can be ensured by adjusting the temperature at the time of withdrawal of the reactant to a range of 20 to 250 ° C., and the withdrawal of the reactant could be made extremely easy. It is.
[0022]
According to the invention, the reactants are withdrawn from the reactor at a temperature in the range of 20 to 250 ° C., preferably 50 to 230 ° C., more preferably 100 to 220 ° C., particularly preferably 150 to 200 ° C. If the temperature is lower than 20 ° C., the viscosity of the reaction product is increased and smooth extraction cannot be performed. In addition, a time for cooling to 20 ° C. or less is required, which is industrially inappropriate. When the temperature exceeds 250 ° C., the temperature of the reaction product at the time of extraction is high, so that the target product or solvent is vaporized on the side of the extraction container, and as a result, these are scattered, At this time, inorganic salts and the like present in the reaction product are entrained, and the apparatus is contaminated industrially.
[0023]
In this invention, the fluidity | liquidity of the more excellent reaction material can be ensured by adjusting to the said 20-250 degreeC temperature range, stirring a reaction material. In particular, since the aromatic fluorine compound which is the object of the present invention uses a fluorinating agent belonging to an inorganic compound, the stirring power per unit volume of the reactant is 0. 0 in order to ensure the reactivity with the fluorinating agent during the reaction. 1-10kw / m^Three, More preferably 0.5 to 7.0 kw / m^Three, Especially 1.0-4.0kw / m^ThreeIt is common to stir with. Conventionally, stirring was stopped after the reaction was completed, but in the present invention, the fluidity of the reactant is ensured by continuing the stirring together with the temperature control. The stirring power during this temperature control may be the same as or different from the stirring power during the reaction, and is 0.1 to 10 kw / m per unit volume of the reaction product.^Three, More preferably 0.5 to 7.0 kw / m^Three, Especially 1.0-4.0kw / m^ThreeOf stirring power. Moreover, the stirring power at the time of taking out a reaction material from a reactor is 0.01-3.0 kw / m as a mobility per unit volume of a reaction material.^ThreeAnd more preferably 0.05 to 2.5 kw / m.^Three, Especially 0.1-2 kw / m^ThreeIt is. This is because, within this range, the fluidity of the reactant suitable for removal from the reactor can be ensured regardless of whether the reactant is contained in the reactant or the amount of the fluorinating agent used. Further, not only at the time of temperature adjustment, the reaction product may be taken out by rotating the stirring blade at the time of taking out.
[0024]
In the present invention, the stirring power per unit volume of the reactant at the time of withdrawal is calculated from the current value of the stirrer before and after withdrawal, and the required stirring power is obtained from the difference, and this is obtained as the reactant. It is calculated by dividing by the volume of.
That is, the stirring power (A) at the time of reaction or cooling of the reaction product (before extraction) is expressed as √3 × voltage × current value 1 × power factor 1/1000 when AC is used. The agitation power (after extraction) (B) is represented by √3 × voltage × current value 2 × power factor 2/1000. Therefore, the agitation power per unit volume at the time of extraction is ((A) − (B) ) / Reactant volume. As indicated by this numerical value, the stirring power at the time of withdrawal indicates the average stirring power of the elapsed time of withdrawal of the reactant.
[0025]
At this time, it is possible to work more smoothly by extracting the reactant under pressure or by extracting the reactant under suction. Specifically, by making the internal pressure of the reactor higher than the external pressure, for example, in the case of an apparatus comprising a reactor and a reactant introduction container connected thereto, the internal pressure of the reactor is changed to the reactant introduction container. By making the pressure higher than the internal pressure, the reaction product can be efficiently extracted from the reactor. Further, the extraction of the reactant under pressure and the extraction of the reactant under suction may be used in combination.
[0026]
Various methods can be used to increase the internal pressure of the reactor above the external pressure. For example, gas may be injected into the reactor when the reactant is extracted, or the internal pressure of the reactant introduction container connected to the reactor may be reduced using a pump. The degree of this pressure reduction varies depending on the viscosity of the reaction product, but when the viscosity of the reaction product measured by a BL type viscometer (manufactured by Tokimec Co., Ltd.) is 2 to 200 cps, The pressure may be set to 0.01 to 2 MPa, preferably 0.05 to 1 MPa, and more preferably 0.1 to 0.5 MPa, so that the pressure is higher than the internal pressure of the reactant introduction container. When the pressure difference is generated, a method of introducing gas into the reactor is preferably used in that the operation is relatively simple and a pressure difference of 0.1 MPa or more can be generated.
[0027]
Any gas can be used as long as it does not adversely affect the reactants and can be used industrially safely. For example, inert gas such as nitrogen, carbon dioxide, helium, argon, air, or oxygen concentration In particular, nitrogen is preferably used because nitrogen does not adversely affect the reactants and is safe and easily available industrially.
[0028]
As a method for extracting the reactant, for example, the inside of the reactor is pressurized with an inert gas such as nitrogen and the reactant is withdrawn with or without stirring. An example is a method in which the internal pressure is set to atmospheric pressure, and the inside of the reactant introduction container is decompressed with a pump or the like, and then the reactant is withdrawn with or without stirring. From the reason that it can be extracted more smoothly and efficiently, it is preferable to extract with stirring. In addition, when extracting an inert gas such as nitrogen that pressurizes the inside of the reactor, the inside of the reactor can be appropriately supplied into the reactor so that the extraction can be smoothly performed while observing the state of the extraction or the pressure inside the reactor. It is good to make it. When a small amount of reactant remains in the reactor, it may be extracted after adding a solvent or the like to the reactor and stirring it to obtain a good slurry.
[0029]
In the method of the present invention, in addition to the unreacted product of the aromatic chlorine compound as the raw material compound and the fluorinating agent, the inorganic salt such as potassium chloride or the remaining unreacted fluorinating agent as a by-product of the reaction is insoluble. Since it remains in the reaction product, the viscosity of the reaction product is high. In particular, when the number of chlorine atoms contained in the aromatic chlorine compound is large, the amount of fluorinating agent used is also increased, resulting in by-product potassium chloride remaining in the reaction product or residual unreacted fluorination. Since the amount of the agent increases, the viscosity of the reaction product increases. From this point of view, the production method of the present invention is an aromatic chlorine containing 4 or 5 chlorine atoms in one compound such as 3,4,5,6-tetrachlorophthalonitrile, pentachlorobenzonitrile and the like. This is particularly effective when a compound is used as a raw material compound. Further, when 2,6-dichlorobenzonitrile or the like is used as a raw material, it may be reacted with a fluorinating agent in the absence of a solvent even if the number of contained chlorine atoms is small, resulting in an increase in the viscosity of the reaction product. . Therefore, when 2,6-dichlorobenzonitrile is used as a raw material compound, the reaction product can be suitably taken out by the present invention even when the halogenation reaction is carried out in the absence of a solvent.
[0030]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
[0031]
(Reference Example 1)
A 300 L stainless steel autoclave was charged with 150 kg of benzonitrile, 52 kg of pentachlorobenzonitrile (0.1891 kgmol) and 60 kg (1.033 kgmol) of spray-dried potassium fluoride, and the air in the autoclave was replaced with nitrogen, followed by stirring. Power 1.0-3.0kw / m^ThreeThe reaction was carried out at 340 ° C. for 18 hours with stirring.
[0032]
After completion of the reaction, the reaction solution was analyzed by gas chromatography. As a result, 31.1 kg (0.1612 kilomol, yield: 85.4 mol%) of pentafluorobenzonitrile, which is the target product, was contained in the reaction solution. , 5-dichloro-2,4,6-trifluorobenzonitrile, 8.2 kg (0.0391 kilomoles).
[0033]
Example 1
A 300 L stainless steel autoclave was charged with 150 kg of benzonitrile, 52 kg of pentachlorobenzonitrile (0.1891 kgmol) and 60 kg (1.033 kgmol) of spray-dried potassium fluoride, and the air in the autoclave was replaced with nitrogen, followed by stirring. Power 1.0-3.0kw / m^ThreeThe reaction was carried out at 340 ° C. for 18 hours with stirring.
[0034]
After completion of the reaction, the reaction solution was stirred with a power of 1.0 to 3.0 kw / m.^ThreeThe reactor was cooled to 150 ° C. with stirring, and the internal pressure of the reactor was increased to 0.3 MPa with nitrogen gas. While stirring, the valve at the bottom of the reactor was released, and the reaction product was connected to the valve at the bottom of the reactor. Extracted to blender. The stirring power per unit volume of the reactant at the time of extraction calculated from the amount of current of the stirrer drive before and after extraction is 0.4 kW / m^ThreeMet. The time required for extraction was 5 minutes.
[0035]
Moreover, as a result of conducting gas chromatography analysis of the extracted reaction product, 30.8 kg (0.1596 kgole, yield 85.0 mol%) of the target product, pentafluorobenzonitrile and the active ingredient were contained in the extraction solution. A certain amount of 3,5-dichloro-2,4,6-trifluorobenzonitrile (8.1 kg (0.0358 kilomol)) was contained, and when the inside of the reactor was observed, almost no reactant remained inside. It wasn't. The recovery rate (recovery rate after extraction based on the yield in Reference Example 1; the same applies hereinafter) was 99%.
[0036]
(Example 2)
A 300 L stainless steel autoclave was charged with 150 kg of benzonitrile, 52 kg of tetrachlorophthalonitrile (0.1955 kgmol) and 50 kg (0.8601 kgmol) of spray-dried potassium fluoride, and the air in the autoclave was replaced with nitrogen, followed by stirring. Power 1.0-3.0kw / m^ThreeThe reaction was carried out at 255 ° C. for 20 hours with stirring.
[0037]
After completion of the reaction, the reaction solution was stirred with a power of 1.0 to 3.0 kw / m.^ThreeThe reactor was cooled to 150 ° C. with stirring, and the pressure inside the reactor was increased to 0.3 MPa with nitrogen gas, and the valve at the bottom of the reactor was released while stirring, and the blender was connected to the valve at the bottom of the reactor. Extracted. The stirring power per unit volume of the reactant at the time of extraction calculated from the amount of current of the stirrer drive before and after extraction is 0.45 kw / m.^ThreeMet. The time required for extraction was 4 minutes. Further, as a result of conducting gas chromatography analysis of the extracted reaction product, the reaction product contained 35.2 kg (0.1760 kgole, yield 90.0 mol%) of the target product, tetrafluorophthalonitrile, and the active ingredient. It contains 2.54 kg (0.0117 kilomol) of 3-chloro-4,5,6-trifluorophthalonitrile, and when the inside of the reactor is observed, almost no reactant remains inside. It was. The recovery rate was 99%.
[0038]
(Example 3)
A 300 L stainless steel autoclave is charged with 150 kg of dimethyl sulfoxide, 52 kg (0.3023 kgmol) of 2,6-dichlorobenzonitrile and 38.6 kg (0.6651 kgmol) of spray-dried potassium fluoride, and the air inside the autoclave is filled with nitrogen. After replacement, stirring power 1.0-3.0 kw / m^ThreeThe reaction was carried out at 160 ° C. for 12 hours with stirring.
[0039]
After completion of the reaction, the reaction solution was stirred with a power of 1.0 to 3.0 kw / m.^ThreeThe blender was cooled to 150 ° C. with stirring at 150 ° C., the reactor internal pressure was increased to 0.2 MPa with nitrogen gas, the valve at the bottom of the reactor was released with stirring, and the reaction product was connected to the valve at the bottom of the reactor Extracted. The stirring power per unit volume of the reactant at the time of extraction calculated from the amount of current of the stirrer drive before and after extraction is 0.38 kw / m.^ThreeMet. The time required for extraction was 4 minutes. In addition, as a result of conducting gas chromatography analysis of the extracted reaction product, 38.8 kg (0.2790 kgol, yield 92.3 mol%) of 2,6-difluorobenzonitrile which is the target product was found in the reaction product. 2-Chloro-6-fluorobenzonitrile, which is an active ingredient, was contained in an amount of 2.12 kg (0.0136 kgol), and when the inside of the reactor was observed, almost no reactant remained inside. The recovery rate was 99%.
[0040]
(Example 4)
In Example 1, the reaction product was extracted in the same manner as in Example 1 except that the temperature of the reaction product at the time of extraction was 100 ° C. As a result, the time required for the extraction was 7 minutes. The recovery rate was 98.5%.
[0041]
(Example 5)
In Example 1, the reaction product was extracted in the same manner as in Example 1 except that the internal pressure of the reactor at the time of extraction was 0.5 MPa, and the time required for extraction was 3 minutes. The recovery rate was 99.5%.
[0042]
(Example 6)
In Example 1, the reaction product was extracted in the same manner as in Example 1 except that the temperature of the reaction product during extraction was 150 ° C., and the pressure on the extraction container side was 0.013 MPa using a pump. The time required for extraction was 6 minutes. The recovery rate was 99.0%.
[0043]
(Comparative Example 1)
In Example 1, the reaction product was extracted in the same manner as in Example 1 except that the temperature of the reaction product at the time of extraction was 10 ° C. As a result, the time required for the extraction was 60 minutes. The recovery rate was 70.0%.
[0044]
(Comparative Example 2)
In Example 1, except that the temperature of the reaction product at the time of extraction was 280 ° C., the reaction product was extracted in the same manner as in Example 1, and the time required for extraction was 3 minutes. The recovery rate was 80%.
[0045]
(Example 7)
A 300 liter stainless steel autoclave was charged with 150 kg of benzonitrile, 50 kg of pentachlorobenzonitrile, and 58 kg of spray-dried potassium fluoride. After the air in the autoclave was replaced with nitrogen, the stirring power was 2.0 to 4.0 kW / m^ThreeThe temperature was raised to 340 ° C. with stirring at, and the reaction was performed at this temperature for 18 hours. After completion of the reaction, the reaction solution was stirred with a power of 2.0 to 4.0 kw / m.^ThreeThe blender was cooled to 190 ° C. with stirring, pressurized to 0.3 MPa with nitrogen gas, the reactor lower valve was released while stirring, and the reactant was connected to the reactor lower valve. Extracted. The stirring power per unit volume of the reactant at the time of extraction calculated from the amount of current of the stirrer drive before and after extraction is 0.5 kW / m^ThreeMet. The time required for extraction was 1 minute. Further, as a result of performing gas chromatography analysis of the extracted reaction product, 32.8 kg (yield 93.7 mol%) of pentafluorobenzonitrile which is the target product and 3-chloro- 1.9 kg of 2,4,5,6-tetrafluorobenzonitrile and 0.4 kg of 3,5, -dichloro-2,4,6-trifluorobenzonitrile were included. When the inside of the reactor was observed, almost no reactant remained in the reactor. The recovery rate was 99.8%.
[0046]
(Example 8)
In Example 7, when extraction was performed in the same manner except that the extraction temperature was 230 ° C., the time required for extraction was almost the same, 8 minutes, and the recovery rate was 95%.
[0047]
Example 9
In Example 7, when extraction was performed in the same manner except that the extraction temperature was 50 ° C., the time required for extraction was 7 minutes. The recovery rate was 96%.
[0048]
(Example 10)
A 300-liter glass-lined reactor equipped with a stirrer and a condenser was charged with 150 kg of sulfolane, 58 kg (0.194 mol) of N-methyl-tetrachlorophthalimide, and 50 g of spray-dried potassium fluoride. After replacing the internal air with nitrogen, the stirring power was 2.0 to 4.0 kw / m.^ThreeThe temperature was raised to 220 ° C. while stirring, and the reaction was carried out at this temperature for 5 hours. After completion of the reaction, the reaction solution was stirred with a power of 2.0 to 4.0 kw / m.^ThreeThe reactor was cooled to 190 ° C. with stirring, and the internal pressure of the reactor was increased to 0.05 MPa with nitrogen gas, and the reaction solution was stirred and the valve at the bottom of the reactor was released. Extracted. The stirring power per unit volume of the reaction product at the time of extraction calculated from the current amount of the stirrer driving unit before and after extraction is 0.48 kw / m.^ThreeMet. The time required for extraction was 2 minutes. As a result of gas chromatography analysis of the extracted reaction product, the extracted solution contained 37 kg (0.1589 mol, yield 81.9 mol%) of the target product, N-methyl-tetrafluorophthalimide. In the interior, almost no reaction product remained. The recovery rate was 99.3%.
[0049]
(Example 11)
In Example 2, the time required for extraction was 2 minutes when extracted in the same manner except that the temperature at the time of extracting the reaction solution was 180 ° C. The recovery rate was 99.6 mol%.
[0050]
(Comparative Example 3)
In Example 7, after completion of the reaction, stirring was stopped, and the reaction solution was extracted at the same temperature except that the temperature at the time of extracting the reaction solution was 260 ° C. The recovery rate was 50%.
[0051]
(Comparative Example 4)
In Example 7, when the reaction was completed and the stirring was stopped, and the temperature at the time of extracting the reaction liquid was set to 15 ° C., the reaction product was hardly extracted.
[0052]
【The invention's effect】
According to the present invention, the reaction product after the halogen exchange reaction can be efficiently extracted from the reactor in a short time and without any residue.

Claims (5)

Aromatic chlorine compounds, fluorinating agent and is a halogen exchange reaction in the process for producing an aromatic fluorine compound, after the halogen exchange reaction, the reaction with stirring power 0.1~10kw / m ³ per unit volume performed by adjusting the temperature range of 20 to 250 [° C. for stirring reactants, the unit volume of the reaction product of 0.01~3.0kw / ^{m 3} further reaction product obtained by the halogen exchange reaction, in a reactor A method for producing an aromatic fluorine compound, wherein the aromatic fluorine compound is withdrawn from the reactor under pressure at a temperature in the range of 50 to 230 ° C. while stirring with an appropriate stirring power.   2. The production method according to claim 1, wherein the reaction product is extracted under suction of the reaction product. The manufacturing method of Claim 1 or 2 whose stirring power per unit volume of the reaction material in the reactor at the time of extraction is 0.05-2.5 kw / m < ³ >. Aromatic chlorine compounds, 3,4,5,6-tetrachloro phthalonitrile, is selected from the group consisting of penta-chlorobenzonitrile and 2,6-dichloro benzonitrile any one of claims 1 to 3 The manufacturing method as described in. The manufacturing method according to any one of claims 1 to 4 , wherein the pressure on the reactor side is 0.01 to 2 MPa in gauge pressure and higher than the internal pressure of the reactant introduction container.