JPH08268979A - Production of 2,3,5,6-tetrafluoroaniline - Google Patents
Production of 2,3,5,6-tetrafluoroanilineInfo
- Publication number
- JPH08268979A JPH08268979A JP7171995A JP7171995A JPH08268979A JP H08268979 A JPH08268979 A JP H08268979A JP 7171995 A JP7171995 A JP 7171995A JP 7171995 A JP7171995 A JP 7171995A JP H08268979 A JPH08268979 A JP H08268979A
- Authority
- JP
- Japan
- Prior art keywords
- tetrafluoroaniline
- sulfuric acid
- water
- reaction
- reactor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- SPSWJTZNOXMMMV-UHFFFAOYSA-N 2,3,5,6-tetrafluoroaniline Chemical compound NC1=C(F)C(F)=CC(F)=C1F SPSWJTZNOXMMMV-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 76
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 42
- 238000006243 chemical reaction Methods 0.000 claims abstract description 30
- ZFQKTZQBBRHWPC-UHFFFAOYSA-N 4-amino-2,3,5,6-tetrafluorobenzonitrile Chemical compound NC1=C(F)C(F)=C(C#N)C(F)=C1F ZFQKTZQBBRHWPC-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000000243 solution Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 239000007864 aqueous solution Substances 0.000 claims description 6
- 230000003301 hydrolyzing effect Effects 0.000 claims description 4
- BEECAQIHCYTZHC-UHFFFAOYSA-N 2,3,4,5-tetrafluoroaniline Chemical compound NC1=CC(F)=C(F)C(F)=C1F BEECAQIHCYTZHC-UHFFFAOYSA-N 0.000 claims description 3
- 230000000911 decarboxylating effect Effects 0.000 claims description 3
- 238000005260 corrosion Methods 0.000 abstract description 9
- 230000007797 corrosion Effects 0.000 abstract description 9
- 239000003905 agrochemical Substances 0.000 abstract description 2
- 239000003814 drug Substances 0.000 abstract description 2
- IQLNTAINVXUGDV-UHFFFAOYSA-N 2-amino-3,4,5,6-tetrafluorobenzonitrile Chemical compound NC1=C(F)C(F)=C(F)C(F)=C1C#N IQLNTAINVXUGDV-UHFFFAOYSA-N 0.000 abstract 1
- 229940079593 drug Drugs 0.000 abstract 1
- 239000002994 raw material Substances 0.000 description 11
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 7
- 239000012043 crude product Substances 0.000 description 5
- 238000004821 distillation Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000012856 packing Methods 0.000 description 5
- GLTGXIGJLCSEAM-UHFFFAOYSA-N 2,3,4,5-tetrafluorobenzonitrile Chemical compound FC1=CC(C#N)=C(F)C(F)=C1F GLTGXIGJLCSEAM-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- ZAFNJMIOTHYJRJ-UHFFFAOYSA-N Diisopropyl ether Chemical compound CC(C)OC(C)C ZAFNJMIOTHYJRJ-UHFFFAOYSA-N 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000013076 target substance Substances 0.000 description 2
- YXWJGZQOGXGSSC-UHFFFAOYSA-N 2,3,4,5,6-pentafluorobenzonitrile Chemical compound FC1=C(F)C(F)=C(C#N)C(F)=C1F YXWJGZQOGXGSSC-UHFFFAOYSA-N 0.000 description 1
- IOQMWOBRUDNEOA-UHFFFAOYSA-N 2,3,5,6-tetrafluorobenzonitrile Chemical compound FC1=CC(F)=C(F)C(C#N)=C1F IOQMWOBRUDNEOA-UHFFFAOYSA-N 0.000 description 1
- 238000005576 amination reaction Methods 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000010533 azeotropic distillation Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 238000006114 decarboxylation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 229910000856 hastalloy Inorganic materials 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- RGCLLPNLLBQHPF-HJWRWDBZSA-N phosphamidon Chemical compound CCN(CC)C(=O)C(\Cl)=C(/C)OP(=O)(OC)OC RGCLLPNLLBQHPF-HJWRWDBZSA-N 0.000 description 1
- 239000012264 purified product Substances 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、硫酸水溶液中で４−ア
ミノ−２，３，５，６−テトラフルオロベンゾニトリル
を加水分解脱炭酸させて、２，３，５，６−テトラフル
オロアニリンを効率よく製造する新規な方法に関するも
のである。The present invention relates to 2,3,5,6-tetrafluoroaniline by hydrolyzing and decarboxylating 4-amino-2,3,5,6-tetrafluorobenzonitrile in an aqueous sulfuric acid solution. The present invention relates to a novel method for efficiently producing
【０００２】本発明で得られる２，３，５，６−テトラ
フルオロアニリンは、主として医薬品および農薬の中間
原料として使用される重要な中間体である。The 2,3,5,6-tetrafluoroaniline obtained in the present invention is an important intermediate mainly used as an intermediate raw material for pharmaceuticals and agricultural chemicals.
【０００３】[0003]
【従来の技術】４−アミノ−２，３，５，６−テトラフ
ルオロベンゾニトリルを硫酸水溶液中で反応させ２，
３，５，６−テトラフルオロアニリンを得る方法は、例
えば、Ｊｏｕｒｎａｌ ｏｆ ｔｈｅ Ｃｈｅｍｉｃａ
ｌ Ｓｏｃｉｅｔｙ．（Ｃ），Ｏｒｇａｎｉｃ Ｃｈｅ
ｍｉｓｔｒｙ Ｐ１３４３〜１３４８ １９７１（ジャ
ナール オブ ザ ケミカル ソシャティ Ｃ オーガ
ニック ケミストリー１９７１年 第１３４３〜１３４
８頁）に開示されている。2. Description of the Related Art 4-Amino-2,3,5,6-tetrafluorobenzonitrile is reacted in an aqueous sulfuric acid solution to
The method for obtaining 3,5,6-tetrafluoroaniline is described in, for example, Journal of the Chemical.
l Society. (C), Organic Che
mystery P1343-1348 1971 (Janal of the Chemical Sociati C Organic Chemistry 1971 1343-134
Page 8).
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、この４
−アミノ−２，３，５，６−テトラフルオロベンゾニト
リルを硫酸水溶液中で加水分解脱炭酸させて２，３，
５，６−テトラフルオロアニリンを得る方法は、副反応
により発生するフッ酸によりステンレスやグラスライニ
ングの反応器を腐食するためハステロイ等の高価な装置
を必要とし、また収率が低く生産性の問題からも望まし
くない。[Problems to be Solved by the Invention]
-Amino-2,3,5,6-tetrafluorobenzonitrile is hydrolyzed and decarboxylated in an aqueous sulfuric acid solution to give 2,3,3.
The method for obtaining 5,6-tetrafluoroaniline requires expensive equipment such as Hastelloy because it corrodes a stainless steel or glass-lined reactor by hydrofluoric acid generated by a side reaction, and the yield is low, which causes a problem of productivity. Is also not desirable.
【０００５】本発明者は、反応器の腐食の問題点を解決
するため鋭意研究を行った結果、４−アミノ−２，３，
５，６−テトラフルオロベンゾニトリルを硫酸水溶液中
に滴下し、生成した２，３，５，６−テトラフルオロア
ニリンを直に水と共沸させると共に、反応器内の硫酸濃
度を一定に保持するために水を供給することにより、結
果として反応器の腐食を抑制し、高収率で２，３，５，
６−テトラフルオロアニリンを得る方法を見出し本発明
を完成した。The present inventor has conducted diligent research to solve the problem of corrosion of the reactor, and as a result, 4-amino-2,3,3
5,6-Tetrafluorobenzonitrile was dropped into an aqueous solution of sulfuric acid to directly azeotrope the produced 2,3,5,6-tetrafluoroaniline with water, and the sulfuric acid concentration in the reactor was kept constant. Water is supplied for this purpose, resulting in suppression of reactor corrosion and high yields of 2, 3, 5,
The present invention has been completed by finding a method for obtaining 6-tetrafluoroaniline.
【０００６】[0006]
【課題を解決するための手段】本発明は、次の反応式
（１）で示されるように、４−アミノ−２，３，５，６
−テトラフルオロベンゾニトリルを硫酸水溶液中で加水
分解脱炭酸させて、２，３，５，６−テトラフルオロア
ニリンを製造するに際し、硫酸水溶液中に４−アミノ−
２，３，５，６−テトラフルオロベンゾニトリルおよび
水を供給し、生成した２，３，５，６−テトラフルオロ
アニリンを水と共沸させて留去しながら反応させること
を特徴とする２，３，５，６−テトラフルオロアニリン
の製造方法である。The present invention provides 4-amino-2,3,5,6 as shown by the following reaction formula (1).
When hydrolyzing and decarboxylating tetrafluorobenzonitrile in an aqueous sulfuric acid solution to produce 2,3,5,6-tetrafluoroaniline, 4-amino-in an aqueous sulfuric acid solution is prepared.
2,3,5,6-tetrafluorobenzonitrile and water are supplied, and the produced 2,3,5,6-tetrafluoroaniline is azeotropically distilled with water to react while distilling off. , 3,5,6-Tetrafluoroaniline.
【０００７】[0007]
【化１】 Embedded image
【０００８】すなわち、本発明は、４−アミノ−２，
３，５，６−テトラフルオロベンゾニトリルを硫酸水溶
液中で加水分解脱炭酸させて、２，３，５，６−テトラ
フルオロアニリンを製造するに際し、硫酸水溶液中に４
−アミノ−２，３，５，６−テトラフルオロベンゾニト
リルおよび水を供給し、生成した２，３，５，６−テト
ラフルオロアニリンを直に水と共に留去させることを特
徴とする２，３，５，６−テトラフルオロアニリンの製
造方法である。That is, the present invention relates to 4-amino-2,
When 3,5,6-tetrafluorobenzonitrile is hydrolyzed and decarboxylated in an aqueous sulfuric acid solution to produce 2,3,5,6-tetrafluoroaniline, 4
-Amino-2,3,5,6-tetrafluorobenzonitrile and water are supplied, and the produced 2,3,5,6-tetrafluoroaniline is directly distilled off together with water. , 5,6-Tetrafluoroaniline.
【０００９】本発明の４−アミノ−２，３，５，６−テ
トラフルオロベンゾニトリルはつぎの反応式（２）で示
されるように２，３，４，５，６−ペンタフルオロベン
ゾニトリルをアンモニア水中でアミノ化することにより
容易に得られる。The 4-amino-2,3,5,6-tetrafluorobenzonitrile of the present invention is prepared by converting 2,3,4,5,6-pentafluorobenzonitrile into ammonia as shown by the following reaction formula (2). It is easily obtained by amination in water.
【００１０】[0010]
【化２】 Embedded image
【００１１】本発明において、４−アミノ−２，３，
５，６−テトラフルオロベンゾニトリルの加水分解脱炭
酸反応に用いる硫酸水溶液の濃度は、５０〜８０重量％
が好ましく、５５〜７０重量％がさらに好ましい。In the present invention, 4-amino-2,3,
The concentration of the aqueous sulfuric acid solution used for the hydrolytic decarboxylation reaction of 5,6-tetrafluorobenzonitrile is 50 to 80% by weight.
Is preferred, and 55 to 70% by weight is more preferred.
【００１２】硫酸は４−アミノ−２，３，５，６−テト
ラフルオロベンゾニトリルの１．５〜１５モル倍用いれ
るが、好ましくは２〜５モル倍の範囲である。Sulfuric acid is used in an amount of 1.5 to 15 mole times that of 4-amino-2,3,5,6-tetrafluorobenzonitrile, preferably 2 to 5 mole times.
【００１３】反応温度は１２０〜１８０℃、好ましくは
１３０〜１６０℃である。この条件の温度を維持しなが
ら４−アミノ−２，３，５，６−テトラフルオロベンゾ
ニトリルおよび水を加え、撹拌をしながら反応させ、生
成した２，３，５，６−テトラフルオロアニリンを水と
共沸させて留去することにより目的物である２，３，
５，６−テトラフルオロアニリンを得ることができる。The reaction temperature is 120 to 180 ° C, preferably 130 to 160 ° C. While maintaining the temperature of this condition, 4-amino-2,3,5,6-tetrafluorobenzonitrile and water were added, and the reaction was performed with stirring to generate 2,3,5,6-tetrafluoroaniline. By distilling off azeotropically with water, the target product is 2, 3,
5,6-Tetrafluoroaniline can be obtained.
【００１４】また、操作圧は他の条件によって左右され
るが、減圧、常圧および加圧のいずれの条件でも実施で
きる。Although the operating pressure depends on other conditions, it can be carried out under any of reduced pressure, normal pressure and increased pressure.
【００１５】本反応のプロセスを以下に説明する。ま
ず、攪拌器を備えた反応器に硫酸水溶液を仕込み所定の
温度まで昇温し、この反応器中に、４−アミノ−２，
３，５，６−テトラフルオロベンゾニトリルを滴下す
る。生成した２，３，５，６−テトラフルオロアニリン
は水と共沸させて留去すると共に反応器内の硫酸濃度を
一定に保持するために水を供給する。この際、硫酸濃度
を一定に保持するための水の供給量は共沸留去した水の
量と反応で消費された硫酸の量により産出して決定され
る。水の供給量が過剰であると硫酸濃度が低下し反応が
進行しなくなる。他方、水の供給量が少ないと硫酸濃度
が上昇し加水分解反応を妨げるほか、反応器内の温度が
上昇するため、２，３，５，６−テトラフルオロアニリ
ンの自己縮合が起きフッ化水素が発生する可能性を生じ
る。The process of this reaction will be described below. First, an aqueous sulfuric acid solution was charged into a reactor equipped with a stirrer and heated to a predetermined temperature, and 4-amino-2,
3,5,6-Tetrafluorobenzonitrile is added dropwise. The 2,3,5,6-tetrafluoroaniline thus produced is azeotropically distilled with water, and water is supplied to keep the sulfuric acid concentration in the reactor constant. At this time, the amount of water supplied to keep the sulfuric acid concentration constant is determined by the amount produced by azeotropic distillation and the amount of sulfuric acid consumed in the reaction. If the amount of water supplied is excessive, the concentration of sulfuric acid will decrease and the reaction will not proceed. On the other hand, when the amount of water supplied is small, the concentration of sulfuric acid rises and the hydrolysis reaction is hindered, and the temperature inside the reactor rises, so that self-condensation of 2,3,5,6-tetrafluoroaniline occurs and hydrogen fluoride occurs. Can occur.
【００１６】また、反応に際し反応器内の２，３，５，
６−テトラフルオロアニリンの濃度は、５重量％以下に
保持することが好ましい。これは反応器内に２，３，
５，６−テトラフルオロアニリンが滞留すると、２，
３，５，６−テトラフルオロアニリン同士あるいは原料
の４−アミノ−２，３，５，６−テトラフルオロベンゾ
ニトリルと２，３，５，６−テトラフルオロアニリンの
縮合反応によりフッ酸が生じ腐食の原因となるためで、
反応器内の２，３，５，６−テトラフルオロアニリンの
濃度が５重量％以下にであれば実用上差し支えなく、好
ましくは２重量％以下にであれば腐食は生じない。In the reaction, 2, 3, 5, inside the reactor
The concentration of 6-tetrafluoroaniline is preferably maintained at 5% by weight or less. This is 2,3 in the reactor
When 5,6-tetrafluoroaniline stays,
Hydrofluoric acid is generated due to condensation reaction between 3,5,6-tetrafluoroaniline or 4-amino-2,3,5,6-tetrafluorobenzonitrile as a raw material and 2,3,5,6-tetrafluoroaniline Because it causes
If the concentration of 2,3,5,6-tetrafluoroaniline in the reactor is 5% by weight or less, there is no practical problem, and if it is 2% by weight or less, corrosion does not occur.
【００１７】同様に原料である４−アミノ−２，３，
５，６−テトラフルオロベンゾニトリルの反応器内の濃
度は１５重量％以下に保持することが好ましい。原料同
士、あるいは２，３，５，６−テトラフルオロアニリン
同士の反応性に比較してかなり低いため、反応器内の濃
度は１５重量％以下であれば実用問題とならない。一
方、０．５重量％以下では、生産性が低くなるので、
０．５〜１５重量％であることが好ましい。Similarly, the starting material 4-amino-2,3,3
The concentration of 5,6-tetrafluorobenzonitrile in the reactor is preferably maintained at 15% by weight or less. Since the reactivities of the raw materials or 2,3,5,6-tetrafluoroaniline are much lower than those of the raw materials, if the concentration in the reactor is 15% by weight or less, there is no practical problem. On the other hand, if it is less than 0.5% by weight, the productivity becomes low,
It is preferably 0.5 to 15% by weight.
【００１８】また、原料の供給方法は、反応開始前に硫
酸水溶液中に仕込まれていても構わないが、好ましくは
反応中に添加する方法がよい。ただし、原料を反応中に
供給する場合、その速度は特に限定されないが、原料同
士の自己縮合の可能性があるため、なるべく目的物であ
る２，３，５，６−テトラフルオロアニリンの生成速度
に近いことが好ましい。The raw materials may be fed into the aqueous sulfuric acid solution before the start of the reaction, but it is preferable to add them during the reaction. However, when the raw materials are supplied during the reaction, the rate is not particularly limited, but since the raw materials may be self-condensed with each other, the production rate of 2,3,5,6-tetrafluoroaniline, which is a target substance, is preferably as high as possible. Is preferable.
【００１９】本発明の反応で反応器内の硫酸濃度を一定
に保持するために供給される水は特に限定されなが、反
応器中から留去される水を用いると、水中に溶解してい
る目的物である２，３，５，６−テトラフルオロアニリ
ンを回収するこができるためより好ましい。In the reaction of the present invention, the water supplied in order to keep the sulfuric acid concentration in the reactor constant is not particularly limited, but if water distilled from the reactor is used, it will dissolve in water. It is more preferable because the desired product, 2,3,5,6-tetrafluoroaniline, can be recovered.
【００２０】本発明によれば、生成した２，３，５，６
−テトラフルオロアニリンは、水と共沸して反応器から
留去される。その後、２，３，５，６−テトラフルオロ
アニリンは分液、抽出などの方法によって単離すること
ができる。このようにして得られた２，３，５，６−テ
トラフルオロアニリンは高純度であり、このまま種々の
用途に用いることができる。また、より高純度の２，
３，５，６−テトラフルオロアニリンが要求される場合
には、適当な蒸留設備を用いて蒸留によってより高純度
の精製品を得ることができる。According to the present invention, the generated 2, 3, 5, 6
-Tetrafluoroaniline is distilled azeotropically with water from the reactor. Thereafter, 2,3,5,6-tetrafluoroaniline can be isolated by a method such as liquid separation or extraction. The thus obtained 2,3,5,6-tetrafluoroaniline has a high purity and can be used as it is for various purposes. In addition, the higher purity of 2,
When 3,5,6-tetrafluoroaniline is required, a higher purity purified product can be obtained by distillation using a suitable distillation facility.
【００２１】このような蒸留設備としては、例えばラシ
ヒリング、ポールリング、イタロックスサドル、ディク
ソンパッキング、マクマホンパッキング、スルーザーパ
ッキングなどを充填した充填塔、泡鐘トレイ、シーブト
レイ、バルブトレイなどのトレイを使用した棚段塔など
通常の蒸留塔として用いられているものが使用できる。
また棚段と充填物層を合わせ持つ混合塔式も用いること
ができる。As such a distillation facility, for example, a packing column filled with Raschig rings, pole rings, Italox saddles, Dixon packing, McMahon packing, sulzer packing, foam bell trays, sieve trays, valve trays and the like are used. What is used as an ordinary distillation column such as a plate tray can be used.
A mixing tower type having both a tray and a packing layer can also be used.
【００２２】蒸留塔の操作圧は１ｍｍＨｇ〜１ｋｇ／ｃ
ｍ2 、好ましくは１０ｍｍＨｇ〜１ｋｇ／ｃｍ2 の範囲
である。The operating pressure of the distillation column is 1 mmHg to 1 kg / c.
m 2 , preferably in the range of 10 mmHg to 1 kg / cm 2 .
【００２３】原料物質の４−アミノ−２，３，５，６−
テトラフルオロベンゾニトリルおよび水の反応器への供
給方法は、４−アミノ−２，３，５，６−テトラフルオ
ロベンゾニトリルおよび水を別々に供給してもよいし、
４−アミノ−２，３，５，６−テトラフルオロベンゾニ
トリルおよび水を混合して供給してもよいが、原料物質
の４−アミノ−２，３，５，６−テトラフルオロベンゾ
ニトリルは反応器に供給する前に溶融しておくのがより
好ましい。The starting material 4-amino-2,3,5,6-
The method for supplying tetrafluorobenzonitrile and water to the reactor may be to separately supply 4-amino-2,3,5,6-tetrafluorobenzonitrile and water,
4-amino-2,3,5,6-tetrafluorobenzonitrile and water may be mixed and supplied, but the starting material 4-amino-2,3,5,6-tetrafluorobenzonitrile is reacted. More preferably, it is melted before being fed to the vessel.
【００２４】本発明で用いられる反応装置の例を示す。An example of the reaction apparatus used in the present invention will be shown.
【００２５】図１に示すように、加熱装置１および攪拌
機２を備えた反応器３に硫酸水溶液を仕込み、導管４か
ら４−アミノ−２，３，５，６−テトラフルオロベンゾ
ニトリルを連続的または間欠的に反応器３に供給し、ま
た導管５から水を連続的または間欠的に反応器３に供給
し、撹拌をしながら、加熱装置１により加熱することに
より反応を行う。反応によって生成した２，３，５，６
−テトラフルオロアニリンを水と共沸させ、導管６から
連続的に抜き出し、凝縮器７で冷却凝縮した後、導管８
から受器９に導入する。しかして、受器９において、２
層に分離した上層から導管１０を通して、２，３，５，
６−テトラフルオロアニリンを得、下層から導管１１を
通して水を分離する。As shown in FIG. 1, a reactor 3 equipped with a heating device 1 and a stirrer 2 was charged with an aqueous sulfuric acid solution, and 4-amino-2,3,5,6-tetrafluorobenzonitrile was continuously fed from a conduit 4. Alternatively, the reaction is performed by intermittently supplying the water to the reactor 3, and continuously or intermittently supplying water from the conduit 5 to the reactor 3, and heating by the heating device 1 while stirring. 2,3,5,6 produced by the reaction
-Tetrafluoroaniline is azeotroped with water, continuously withdrawn from the conduit 6, cooled and condensed in the condenser 7, and then the conduit 8
To the receiver 9. Then, in the receiver 9, 2
From the upper layer separated into layers, through the conduit 10, 2, 3, 5,
6-Tetrafluoroaniline is obtained and water is separated from the lower layer through conduit 11.
【００２６】[0026]
【作用】本発明によれば、４−アミノ−２，３，５，６
−テトラフルオロベンゾニトリルのみを硫酸水溶液中に
直接反応に供するのでなく、硫酸水溶液中に４−アミノ
−２，３，５，６−テトラフルオロベンゾニトリルと水
を制御して導入し、生成した２，３，５，６−テトラフ
ルオロアニリンを水を共沸させて連続的に直ちに除去す
ることにより、原料と生成物との縮合反応によるフッ酸
の生成を避け、反応器の腐食の問題点を解決することが
でき高収率、高純度で２，３，５，６−テトラフルオロ
アニリンを得る新規な製法であり、溶剤を使用しないた
め生産性が高く、工業的に極めて有利な方法である。According to the present invention, 4-amino-2,3,5,6
-Tetrafluorobenzonitrile alone was not directly subjected to the reaction in a sulfuric acid aqueous solution, but 4-amino-2,3,5,6-tetrafluorobenzonitrile and water were controlled and introduced into the sulfuric acid aqueous solution to generate 2 , 3,5,6-Tetrafluoroaniline is azeotropically distilled with water to immediately and continuously remove it, thereby avoiding the production of hydrofluoric acid due to the condensation reaction between the raw material and the product, and to prevent the problem of corrosion of the reactor. It is a novel production method that can be solved to obtain 2,3,5,6-tetrafluoroaniline in high yield and high purity. Since it does not use a solvent, it has high productivity and is an industrially extremely advantageous method. .
【００２７】[0027]
【実施例】以下実施例により本発明を具体的に説明する
が、これらは単なる例示であり、本発明がこれら実施例
により限定されるものではない。The present invention will be described in detail with reference to the following examples, but these are merely examples and the present invention is not limited to these examples.
【００２８】実施例１ 図１に示すように、加熱装置１および攪拌器２を備えた
容量３００リットルのグラスライニング製反応器３に硫
酸１６２ｋｇと純水１０８ｋｇよりなる６０重量％硫酸
水溶液を仕込み、１４０℃に加熱した。この反応器に原
料である４−アミノ−２，３，５，６−テトラフルオロ
ベンゾニトリルを１３５ｋｇを導管４より毎時８ｋｇの
速度で、また水を導管５より２５ｋｇの速度で供給し、
撹拌をしながら１４０℃で反応を行なった。反応によっ
て生成した２，３，５，６−テトラフルオロアニリンは
速やかに水と共沸させ、導管６より反応器から留去させ
た。そして、共沸分は冷却器７で冷却凝縮された後、導
管８より受器９に導入した。反応中の平均流出速度は
２，３，５，６−テトラフルオロアニリンが毎時５．２
ｋｇ、水が２５．５ｋｇであった。反応開始後２０時間
後に２，３，５，６−テトラフルオロアニリンの流出が
停止したので、反応を終了した。受器９に導入した２，
３，５，６−テトラフルオロアニリンは静置することに
より容易に分液され、２，３，５，６−テトラフルオロ
アニリンの粗製品１０１．５ｋｇを回収した。Example 1 As shown in FIG. 1, a glass-lined reactor 3 having a capacity of 300 liters equipped with a heating device 1 and a stirrer 2 was charged with a 60 wt% sulfuric acid aqueous solution containing 162 kg of sulfuric acid and 108 kg of pure water. Heated to 140 ° C. 135 kg of 4-amino-2,3,5,6-tetrafluorobenzonitrile as a raw material was fed to the reactor through the conduit 4 at a rate of 8 kg / h, and water was fed through the conduit 5 at a rate of 25 kg,
The reaction was carried out at 140 ° C. with stirring. The 2,3,5,6-tetrafluoroaniline produced by the reaction was rapidly azeotroped with water and distilled from the reactor through the conduit 6. Then, the azeotropic component was cooled and condensed in the cooler 7, and then introduced into the receiver 9 through the conduit 8. The average outflow rate during the reaction was 5.2,3,5,6-tetrafluoroaniline at 5.2 hr.
kg and water were 25.5 kg. After 20 hours from the start of the reaction, the outflow of 2,3,5,6-tetrafluoroaniline stopped, so the reaction was terminated. 2, which was introduced into the receiver 9
3,5,6-Tetrafluoroaniline was easily separated by allowing it to stand, and 101.5 kg of a crude product of 2,3,5,6-tetrafluoroaniline was recovered.
【００２９】分析の結果、この２，３，５，６−テトラ
フルオロアニリンの粗製品の純度は９５．３％であり、
不純物０．７％と原料の４−アミノ−２，３，５，６−
テトラフルオロベンゾニトリルを４．０％を含んでいた
（収量９６．２ｋｇ、収率８２．５％）。As a result of the analysis, the purity of the crude product of 2,3,5,6-tetrafluoroaniline was 95.3%,
Impurities 0.7% and raw material 4-amino-2,3,5,6-
It contained 4.0% of tetrafluorobenzonitrile (yield 96.2 kg, yield 82.5%).
【００３０】また、反応開始後１時間後毎に反応液を採
取して分析した結果を表１に示す。Table 1 shows the results of analysis by collecting the reaction solution every hour after the start of the reaction.
【００３１】[0031]
【表１】 [Table 1]
【００３２】反応終了後、反応器に残留する硫酸層を抜
き取り水で洗浄後、反応器内を観察したが、腐食は検出
されなかった。After completion of the reaction, the sulfuric acid layer remaining in the reactor was taken out and washed with water, and the inside of the reactor was observed, but no corrosion was detected.
【００３３】比較例１ 容量３リットルのガラス製セパプルフラスコに硫酸１６
２０ｇと純水１０８０ｇ、４−アミノ−２，３，５，６
−テトラフルオロベンゾニトリルを１３５０ｇ（７．１
０ｍｏｌ）を仕込み、還流温度下１０時間反応を行なっ
た。反応終了後、反応混合物を容量２リットルの水中に
投入し、ジイソプロピルエーテルで２回抽出し、その後
ジイソプロピルエーテルを留去することにより、目的物
の２，３，５，６−テトラフルオロアニリンの粗製品７
３５ｇを得た。Comparative Example 1 Sulfuric acid 16 was placed in a glass separable flask having a capacity of 3 liters.
20 g and pure water 1080 g, 4-amino-2,3,5,6
1350 g of tetrafluorobenzonitrile (7.1
(0 mol) was charged and the reaction was carried out at the reflux temperature for 10 hours. After completion of the reaction, the reaction mixture was poured into water having a volume of 2 liters, extracted twice with diisopropyl ether, and then diisopropyl ether was distilled off to obtain a crude product of 2,3,5,6-tetrafluoroaniline as a target substance. Product 7
35 g were obtained.
【００３４】分析の結果、この２，３，５，６−テトラ
フルオロアニリンの粗製品の純度は９５．８％であり、
原料０．４％、不純物３．８％を含んでいた（収量７０
４ｇ、収率６０．１％）。As a result of the analysis, the purity of the crude product of 2,3,5,6-tetrafluoroaniline was 95.8%,
It contained 0.4% of raw material and 3.8% of impurities (yield 70
4 g, yield 60.1%).
【００３５】反応終了後、容量３リットルのガラス製セ
パプルフラスコを洗浄後、反応器内を観察したところ、
気液の界面を中心に激しい腐食が見られた。After completion of the reaction, the inside of the reactor was observed after washing the glass separable flask having a capacity of 3 liters.
Severe corrosion was observed mainly at the gas-liquid interface.
【００３６】比較例２ 比較例１において、反応時間を１時間とした以外は比較
例１と同様に操作を行なった。得られた２，３，５，６
−テトラフルオロアニリンの粗製品の純度は、１７％で
あり、原料の４−アミノ−２，３，５，６−テトラフル
オロベンゾニトリルを８１％、不純物２％を含んでい
た。反応時間が短いため未反応であった。Comparative Example 2 The procedure of Comparative Example 1 was repeated except that the reaction time was changed to 1 hour. Obtained 2, 3, 5, 6
The purity of the crude product of tetrafluoroaniline was 17%, containing 81% of the starting material 4-amino-2,3,5,6-tetrafluorobenzonitrile and 2% of impurities. Since the reaction time was short, it was unreacted.
【００３７】反応終了後、容量３リットルのガラス製セ
パプルフラスコを洗浄し、ついで反応器内を観察したと
ころ、気液の界面を中心に激しい腐食が見られた。After the completion of the reaction, the glass separable flask having a capacity of 3 liters was washed, and then the inside of the reactor was observed. As a result, severe corrosion was observed mainly at the gas-liquid interface.
【００３８】[0038]
【発明の効果】本発明は硫酸水溶液中に２，３，５，６
−テトラフルオロベンゾアニリンと共に水を制御して導
入し、硫酸濃度を制御しながら生成した２，３，５，６
−テトラフルオロアニリンを水を共沸させて直ちに分離
除去することにより、反応器の腐食を抑制し、高収率の
２，３，５，６−テトラフルオロアニリンを得る工業的
に極めて有利な方法である。INDUSTRIAL APPLICABILITY The present invention uses 2,3,5,6 in an aqueous sulfuric acid solution.
-2,3,5,6 produced by controlling the introduction of water with tetrafluorobenzoaniline and controlling the sulfuric acid concentration
An industrially extremely advantageous method for obtaining a high yield of 2,3,5,6-tetrafluoroaniline by inhibiting the corrosion of the reactor by immediately separating and removing tetrafluoroaniline by azeotropically distilling water Is.
【図１】は、本発明を実施するプロセスの概略図であるFIG. 1 is a schematic diagram of a process for practicing the present invention.
１…加熱装置 ２…攪拌器 ３…反応器 ４…導管 ５…導管 ６…導管 ７…凝縮器 ８…導管 ９…受器 DESCRIPTION OF SYMBOLS 1 ... Heating device 2 ... Stirrer 3 ... Reactor 4 ... Conduit 5 ... Conduit 6 ... Conduit 7 ... Condenser 8 ... Conduit 9 ... Receiver
Claims (4)
ルオロベンゾニトリルを硫酸水溶液中で加水分解脱炭酸
させて、２，３，５，６−テトラフルオロアニリンを製
造するに際し、生成した２，３，５，６−テトラフルオ
ロアニリンを水と共沸させて留去しながら反応させるこ
とを特徴とする２，３，５，６−テトラフルオロアニリ
ンの製造方法。1. A method for producing 2,3,5,6-tetrafluoroaniline by hydrolyzing and decarboxylating 4-amino-2,3,5,6-tetrafluorobenzonitrile in an aqueous sulfuric acid solution. The method for producing 2,3,5,6-tetrafluoroaniline, which comprises reacting the above 2,3,5,6-tetrafluoroaniline with water while azeotropically distilling it off.
フルオロアニリンの濃度が５重量％以下に保持されてな
る請求項１に記載の２，３，５，６−テトラフルオロア
ニリンの製造方法。2. The 2,3,5,6-tetrafluoroaniline of claim 1, wherein the concentration of 2,3,5,6-tetrafluoroaniline in the sulfuric acid aqueous solution is maintained at 5% by weight or less. Production method.
量％に保持されてなる請求項１または２に記載の２，
３，５，６−テトラフルオロアニリンの製造方法。3. The method according to claim 1 or 2, wherein the sulfuric acid concentration in the sulfuric acid aqueous solution is maintained at 50 to 80% by weight.
A method for producing 3,5,6-tetrafluoroaniline.
５０〜８０重量％に保持しながら反応させてなる請求項
１〜３のいずれか一つに記載の２，３，５，６−テトラ
フルオロアニリンの製造方法。4. The method according to claim 1, wherein the reaction is carried out while adding water to maintain the sulfuric acid concentration in the aqueous sulfuric acid solution at 50 to 80% by weight. -Method for producing tetrafluoroaniline.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07171995A JP3710514B2 (en) | 1995-03-29 | 1995-03-29 | Method for producing 2,3,5,6-tetrafluoroaniline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07171995A JP3710514B2 (en) | 1995-03-29 | 1995-03-29 | Method for producing 2,3,5,6-tetrafluoroaniline |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08268979A true JPH08268979A (en) | 1996-10-15 |
| JP3710514B2 JP3710514B2 (en) | 2005-10-26 |
Family
ID=13468620
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP07171995A Expired - Fee Related JP3710514B2 (en) | 1995-03-29 | 1995-03-29 | Method for producing 2,3,5,6-tetrafluoroaniline |
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| Country | Link |
|---|---|
| JP (1) | JP3710514B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1229015A1 (en) * | 2001-02-02 | 2002-08-07 | Nippon Shokubai Co., Ltd. | Method for production of aromatic compounds |
| JP2008156355A (en) * | 2006-12-20 | 2008-07-10 | Evonik Degussa Gmbh | Continuous method for decarboxylating carboxylic acid |
| CN107915647A (en) * | 2017-12-05 | 2018-04-17 | 大连奇凯医药科技有限公司 | A kind of synthetic method of 2,3,5,6 tetrafluoroaniline |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103012162B (en) * | 2012-12-25 | 2014-12-03 | 大连奇凯医药科技有限公司 | Preparation method of pentafluoroaniline |
-
1995
- 1995-03-29 JP JP07171995A patent/JP3710514B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1229015A1 (en) * | 2001-02-02 | 2002-08-07 | Nippon Shokubai Co., Ltd. | Method for production of aromatic compounds |
| US6521794B2 (en) | 2001-02-02 | 2003-02-18 | Nippon Shokubai Co., Ltd. | Method for production of aromatic compounds |
| JP2008156355A (en) * | 2006-12-20 | 2008-07-10 | Evonik Degussa Gmbh | Continuous method for decarboxylating carboxylic acid |
| CN107915647A (en) * | 2017-12-05 | 2018-04-17 | 大连奇凯医药科技有限公司 | A kind of synthetic method of 2,3,5,6 tetrafluoroaniline |
| CN107915647B (en) * | 2017-12-05 | 2020-02-28 | 大连奇凯医药科技有限公司 | Synthetic method of 2,3,5,6-tetrafluoroaniline |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3710514B2 (en) | 2005-10-26 |
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