JPH0586000A - Method for producing 2-amino-4-fluorobenzoic acid - Google Patents
Method for producing 2-amino-4-fluorobenzoic acidInfo
- Publication number
- JPH0586000A JPH0586000A JP3276765A JP27676591A JPH0586000A JP H0586000 A JPH0586000 A JP H0586000A JP 3276765 A JP3276765 A JP 3276765A JP 27676591 A JP27676591 A JP 27676591A JP H0586000 A JPH0586000 A JP H0586000A
- Authority
- JP
- Japan
- Prior art keywords
- acid
- amino
- fluorobenzoic acid
- fluoro
- producing
- 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.)
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は医農薬等の中間体として
有用な２−アミノ−４−フルオロ安息香酸の新規かつ工
業的に有利な製造方法に関するものである。FIELD OF THE INVENTION The present invention relates to a novel and industrially advantageous process for producing 2-amino-4-fluorobenzoic acid, which is useful as an intermediate for medicines and agricultural chemicals.
【０００２】[0002]
【従来の技術】従来、２−アミノ−４−フルオロ安息香
酸は、４−フルオロ−２−ニトロトルエンを酸化して４
−フルオロ−２−ニトロ安息香酸とし（C.Iemuyne et a
l.,Biochimie,Vol 55,233(1973) 、G.Valkanes and H.H
opff,J.Chem.Soc.,1925,(1963)、E.Benjamin et al.,J.
Bio.Chem.,Vol 207,441(1954) ）、これを還元する方法
（チェコスロバキア特許第246349号、同第246350号(198
7)）、及び４−フルオロ−２−ニトロトルエンを還元し
て２−アミノ−４−フルオロトルエンとし、次いでアミ
ノ基をアセチルで保護した後に、酸化し、加水分解して
得る方法（E.A.Stech and L.T.Fletcher,J.Am.Chem.So
c.,Vol 70,439(1948)）が知られている。2. Description of the Related Art Conventionally, 2-amino-4-fluorobenzoic acid is obtained by oxidizing 4-fluoro-2-nitrotoluene to give 4
-Fluoro-2-nitrobenzoic acid (C. Iemuyne et a
l., Biochimie, Vol 55,233 (1973), G. Valkanes and HH
opff, J. Chem. Soc., 1925, (1963), E. Benjamin et al., J.
Bio.Chem., Vol 207,441 (1954)) and a method for reducing the same (Czechoslovak Patent Nos. 246349 and 246350 (198).
7)) and 4-fluoro-2-nitrotoluene are reduced to 2-amino-4-fluorotoluene, and then the amino group is protected with acetyl, followed by oxidation and hydrolysis (EAStech and LTFletcher, J.Am.Chem.So
c., Vol 70,439 (1948)) is known.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、出発原
料の４−フルオロ−２−ニトロトルエンは、４−アミノ
−２−ニトロトルエンのBalz-Schiemann反応により得ら
れるが（G.Schiemann,Chem.Ber.,Vol 62,1795 、E.Benj
amin et al.,J.Bio.Chem.,Vol 207,441(1954) 、及びE.
A.Stech and L.T.Fletcher,J.Am.Chem.Soc.,Vol 70,439
(1948)）、バッチ効率が低く、しかも人体に有害なホウ
フッ化水素酸を使用し、さらに熱、衝撃に対して爆発性
のあるジアゾニウム塩を経由するため、工業的に容易に
入手できる出発原料ではない。However, the starting material 4-fluoro-2-nitrotoluene can be obtained by the Balz-Schiemann reaction of 4-amino-2-nitrotoluene (G. Schiemann, Chem. Ber., Vol. 62,1795, E. Benj
amin et al., J. Bio. Chem., Vol 207,441 (1954), and E.
A. Stech and LTFletcher, J. Am. Chem. Soc., Vol 70,439
(1948)), low batch efficiency, and uses borofluoric acid, which is harmful to the human body, and is passed through a diazonium salt that is explosive to heat and shock, so it is an industrially easily available starting material. is not.
【０００４】[0004]
【課題を解決するための手段】本発明は、従来法に比べ
て製造上安全で工業的に有利な出発原料を使用し、容易
な方法でかつ高収率で２−アミノ−４−フルオロ安息香
酸を製造する方法を提供する下記の発明である。DISCLOSURE OF THE INVENTION The present invention uses 2-amino-4-fluorobenzoic acid in a simple manner and in a high yield by using starting materials which are safer in production and industrially advantageous than conventional methods. The following invention provides a method for producing an acid.
【０００５】２−アミノ−４−フルオロ安息香酸を製造
するにあたり、２位が未置換でかつ少なくとも５位に塩
素原子あるいは臭素原子を有する４−フルオロハロゲノ
安息香酸をニトロ化せしめて４−フルオロ−２−ニトロ
ハロゲノ安息香酸とし、次いでこれを還元することを特
徴とする２−アミノ−４−フルオロ安息香酸の製造方
法。In producing 2-amino-4-fluorobenzoic acid, 4-fluoro-halogenobenzoic acid, which is unsubstituted at the 2-position and has a chlorine atom or a bromine atom at the 5-position, is nitrated to give 4-fluoro-benzoic acid. A process for producing 2-amino-4-fluorobenzoic acid, which comprises producing 2-nitrohalogenobenzoic acid and then reducing this.
【０００６】本発明における出発原料である４−フルオ
ロハロゲノ安息香酸は、ニトロ基が導入される２位が未
置換、即ち水素原子である必要がある。さらに、５位に
は塩素原子あるいは臭素原子を有する必要がある。ま
た、３位と６位はそれぞれ未置換であっても、塩素原子
あるいは臭素原子を有していてもよい。好ましい４−フ
ルオロハロゲノ安息香酸は３−クロロ−４−フルオロ安
息香酸である。なお、化合物の名称は標準命名法に従う
ので、相対的な置換基の位置は上記説明の位置と異なる
場合がある（例えば、３−クロロ−４−フルオロ安息香
酸は上記説明の位置で表わすと５−クロロ−４−フルオ
ロ安息香酸である）。In the 4-fluorohalogenobenzoic acid which is the starting material in the present invention, the 2-position into which the nitro group is introduced must be unsubstituted, that is, a hydrogen atom. Further, it is necessary to have a chlorine atom or a bromine atom at the 5-position. Further, the 3-position and the 6-position may each be unsubstituted or may have a chlorine atom or a bromine atom. The preferred 4-fluorohalogenobenzoic acid is 3-chloro-4-fluorobenzoic acid. Since the names of the compounds follow standard nomenclature, the positions of the relative substituents may be different from the positions described above (for example, 3-chloro-4-fluorobenzoic acid is 5 -Chloro-4-fluorobenzoic acid).
【０００７】出発原料の４−フルオロハロゲノ安息香酸
は、市販の化合物やそれから容易に製造することができ
る化合物である。例えば、市販の工業原料である３−ク
ロロ−４−フルオロベンゾニトリルあるいは３−クロロ
−４−フルオロベンゾトリフルオリドの加水分解によっ
て高収率で容易に３−クロロ−４−フルオロ安息香酸が
得られる。4-Fluorohalogenobenzoic acid as a starting material is a commercially available compound or a compound which can be easily produced therefrom. For example, 3-chloro-4-fluorobenzoic acid can be easily obtained in a high yield by hydrolysis of commercially available industrial raw material 3-chloro-4-fluorobenzonitrile or 3-chloro-4-fluorobenzotrifluoride. ..
【０００８】本発明方法におけるニトロ化は４−フルオ
ロハロゲノ安息香酸を通常のニトロ化反応によって行う
ことができる。即ち、硝酸をニトロ化剤としてニトロ化
を行うことができる。通常は、硝酸とともに硫酸などの
酸が併用される。３−クロロ−４−フルオロ安息香酸の
ニトロ化により、新規化合物である３−クロロ−４−フ
ルオロ−６−ニトロ安息香酸が高収率で得られる。４−
フルオロハロゲノ安息香酸のニトロ化によって得られる
４−フルオロ−２−ニトロハロゲノ安息香酸は、再結
晶、濾過等の手段を用いて単離し、次の還元反応に供さ
れる。The nitration in the method of the present invention can be carried out by a conventional nitration reaction of 4-fluorohalogenobenzoic acid. That is, nitration can be performed using nitric acid as a nitrating agent. Usually, an acid such as sulfuric acid is used together with nitric acid. Nitration of 3-chloro-4-fluorobenzoic acid gives the new compound 3-chloro-4-fluoro-6-nitrobenzoic acid in high yield. 4-
4-Fluoro-2-nitrohalogenobenzoic acid obtained by nitration of fluorohalogenobenzoic acid is isolated by a means such as recrystallization or filtration, and then used for the next reduction reaction.
【０００９】４−フルオロ−２−ニトロハロゲノ安息香
酸の還元は、接触還元反応、即ち水素化触媒存在下水素
ガスによる還元反応で行われることが好ましい。ニトロ
基のアミノ基への変換と同時に脱ハロゲン（塩素原子あ
るいは臭素原子の水素原子への置換）が進行する。水素
化触媒としては例えばラネーニッケル触媒あるいはパラ
ジウムを２〜10wt％担持した活性炭触媒を使用し、還元
すべき４−フルオロ−２−ニトロハロゲノ安息香酸に対
して、これら水素化触媒を１〜30wt％、好ましくは２〜
10wt％存在させることが適当である。The reduction of 4-fluoro-2-nitrohalogenobenzoic acid is preferably carried out by a catalytic reduction reaction, that is, a reduction reaction with hydrogen gas in the presence of a hydrogenation catalyst. Dehalogenation (substitution of chlorine atom or bromine atom to hydrogen atom) proceeds simultaneously with conversion of nitro group to amino group. As the hydrogenation catalyst, for example, a Raney nickel catalyst or an activated carbon catalyst carrying 2 to 10 wt% of palladium is used, and 1 to 30 wt% of these hydrogenation catalysts is added to 4-fluoro-2-nitrohalogenobenzoic acid to be reduced. Preferably 2
It is suitable to make it 10 wt%.
【００１０】還元反応における反応溶媒としては、メタ
ノール、エタノール、イソプロピルアルコール等の低級
アルコールを使用するのが好ましく、その使用量は、４
−フルオロ−２−ニトロハロゲノ安息香酸に対し、１〜
20倍重量、好ましくは２〜10倍重量が適当である。As the reaction solvent in the reduction reaction, it is preferable to use a lower alcohol such as methanol, ethanol or isopropyl alcohol, and the amount thereof is 4
1 to fluoro-2-nitrohalogenobenzoic acid
20 times weight, preferably 2 to 10 times weight is suitable.
【００１１】還元反応において生成するハロゲン化水素
を中和する目的で、酢酸ナトリウム、酸化マグネシウ
ム、水酸化ナトリウム等の無機塩基、または、トリエチ
ルアミン、ピリジン等のアミン系有機塩基を反応系中に
存在させることが好ましい。これらの塩基の使用量は生
成するハロゲン化水素を中和するために必要な理論量の
１〜５倍重量が好ましく、好ましくは 1.1〜２倍重量で
ある。For the purpose of neutralizing hydrogen halide formed in the reduction reaction, an inorganic base such as sodium acetate, magnesium oxide, sodium hydroxide or the like, or an amine type organic base such as triethylamine, pyridine or the like is allowed to exist in the reaction system. Preferably. The amount of these bases used is preferably 1 to 5 times by weight, and preferably 1.1 to 2 times by weight, of the theoretical amount necessary for neutralizing the hydrogen halide produced.
【００１２】還元反応の反応温度、時間、あるいは圧力
等の反応条件は、適宜最適な条件を選定すればよいが、
およそ10〜100 ℃の温度、 0.5〜10時間の反応時間及び
1.0〜10kg/cm2の水素圧で実施し得る。還元反応生成物
を濾過、溶媒留去、抽出、再結晶等の通常の分離操作を
経て精製することにより、目的とする２−アミノ−４−
フルオロ安息香酸が高純度で収率よく得られる。The reaction conditions such as reaction temperature, time, pressure, etc. for the reduction reaction may be selected as appropriate.
A temperature of approximately 10 to 100 ° C, a reaction time of 0.5 to 10 hours and
It can be carried out at a hydrogen pressure of 1.0 to 10 kg / cm 2 . The reduction reaction product is purified through usual separation operations such as filtration, solvent removal, extraction and recrystallization to give the desired 2-amino-4-
Fluorobenzoic acid can be obtained in high purity with high yield.
【００１３】以下に本発明の実施例をあげて具体的に説
明するが、本発明は、その要旨を超えない限り、以下の
実施例に限定されるものではない。The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
【００１４】[0014]
実施例１−１ 100mlの４ツ口フラスコ中に３−クロロ−４−フルオロ
安息香酸 5.0ｇ、二塩化エタン20ml及び濃硫酸16ｇを仕
込み、撹拌下に室温で98％硝酸４ｇを滴下し、その後、
40℃で６時間反応させた。冷却後、反応混合物を氷水(1
00ｇ）中に注ぎ、有機層を分液し、水層を二塩化エタン
で抽出した。Example 1-1 In a 100 ml four-necked flask, 5.0 g of 3-chloro-4-fluorobenzoic acid, 20 ml of ethane dichloride and 16 g of concentrated sulfuric acid were charged, and 4 g of 98% nitric acid was added dropwise at room temperature with stirring. ,
The reaction was carried out at 40 ° C for 6 hours. After cooling, the reaction mixture was cooled with ice water (1
00 g), the organic layer was separated, and the aqueous layer was extracted with ethane dichloride.
【００１５】有機層及び抽出液は一緒に合わせ、飽和食
塩水で洗浄した。二塩化エタンを留去するとニトロ体が
6.24ｇ（収率99％）得られた。ＨＰＬＣ（高性能液体ク
ロマトグラフィー）により分析したところ、このニトロ
体は目的とする３−クロロ−４−フルオロ−６−ニトロ
安息香酸90％及びその異性体10％からなる混合物であっ
た。これを20倍重量の二塩化エタンから再結晶すると３
−クロロ−４−フルオロ−６−ニトロ安息香酸が3.42ｇ
得られた。この生成物の物性は以下の通りであった。The organic layer and the extract were combined together and washed with saturated saline. When ethane dichloride is distilled off, the nitro form becomes
6.24 g (99% yield) was obtained. When analyzed by HPLC (high performance liquid chromatography), the nitro form was a mixture consisting of 90% of the target 3-chloro-4-fluoro-6-nitrobenzoic acid and 10% of its isomer. When recrystallized from 20 times the weight of ethane dichloride, 3
3.42 g of -chloro-4-fluoro-6-nitrobenzoic acid
Was obtained. The physical properties of this product were as follows.
【００１６】融点：156 〜157 ℃ ＨＰＬＣ純度：99％ ＩＲ (KBr) 3100〜2300 cm-1 (O-H) 1710 cm-1(C=O) 1600,1540 cm-1(NO2) 1500,1420,900 cm-1 ＮＭＲ (CDCl3) δ 7.57 (1H,d,J=6.8Hz) 7.87 (1H,d,J=8.0Hz)Melting point: 156-157 ° C HPLC purity: 99% IR (KBr) 3100-2300 cm -1 (OH) 1710 cm -1 (C = O) 1600,1540 cm -1 (NO 2 ) 1500,1420, 900 cm -1 NMR (CDCl 3 ) δ 7.57 (1H, d, J = 6.8Hz) 7.87 (1H, d, J = 8.0Hz)
【００１７】実施例１−２ 100ml 耐圧硝子製反応器中に、実施例１−１で製造した
３−クロロ−４−フルオロ−６−ニトロ安息香酸 3.0
ｇ、トリエチルアミン1.5ｇ、２wt％パラジウム担持活
性炭触媒 0.3ｇ及びメタノール50mlを仕込み、撹拌しな
がら水素（２〜５kg/cm2）を通じ、60〜100 ℃で６時間
反応させた。反応終了後、触媒を濾別し、メタノール留
去後、クロロホルムに溶解させ、水洗後、クロロホルム
を留去すると結晶が2.10ｇ得られた。これをトルエンか
ら再結晶すると２−アミノ−４−フルオロ安息香酸が1.
70ｇ（収率80％）得られた。ｍｐ．193 〜194 ℃、ＨＰ
ＬＣ純度99.2％。Example 1-2 3-chloro-4-fluoro-6-nitrobenzoic acid 3.0 prepared in Example 1-1 in a 100 ml pressure resistant glass reactor.
g, triethylamine (1.5 g), 2 wt% palladium-supported activated carbon catalyst (0.3 g) and methanol (50 ml) were charged, and hydrogen (2 to 5 kg / cm 2 ) was passed while stirring to react at 60 to 100 ° C. for 6 hours. After completion of the reaction, the catalyst was filtered off, methanol was distilled off, the residue was dissolved in chloroform, washed with water, and then chloroform was distilled off to obtain 2.10 g of crystals. When this was recrystallized from toluene, 2-amino-4-fluorobenzoic acid was 1.
70 g (yield 80%) was obtained. mp. 193-194 ° C, HP
LC purity 99.2%.
【００１８】実施例２ 実施例１−１の方法で製造した３−クロロ−４−フルオ
ロ−６−ニトロ安息香酸 3.0ｇ、トリエチルアミン 1.5
ｇ、ラネーニッケル触媒0.3ｇ及びメタノール50mlを反
応容器に仕込み、撹拌下に水素（2.5kg/cm2 ）を通じ、
60〜70℃で８時間反応させた。反応生成物を実施例１−
２と同様に処理することにより２−アミノ−４−フルオ
ロ安息香酸1.76ｇ（収率83％）が得られた。Example 2 3.0 g of 3-chloro-4-fluoro-6-nitrobenzoic acid prepared by the method of Example 1-1, 1.5 of triethylamine
g, Raney nickel catalyst 0.3 g and methanol 50 ml were charged into a reaction vessel, and hydrogen (2.5 kg / cm 2 ) was passed under stirring,
The reaction was carried out at 60 to 70 ° C for 8 hours. The reaction product was obtained from Example 1-
By treating in the same manner as in 2, 2-amino-4-fluorobenzoic acid (1.76 g, yield 83%) was obtained.
【００１９】実施例３ 実施例１−１の方法で製造した３−クロロ−４−フルオ
ロ−６−ニトロ安息香酸 3.0ｇ、酸化マグネシウム 0.6
ｇ、ラネーニッケル触媒 0.3ｇ及びメタノール30mlを反
応容器に仕込み、撹拌下に60〜70℃で８時間水素（２〜
５kg/cm2）を通じた。反応生成物を実施例１−２と同様
に処理することにより、２−アミノ−４−フルオロ安息
香酸1.74ｇ（収率82％）が得られた。Example 3 3.0 g of 3-chloro-4-fluoro-6-nitrobenzoic acid prepared by the method of Example 1-1, 0.6 of magnesium oxide
g, Raney nickel catalyst 0.3 g and methanol 30 ml were charged into a reaction vessel, and hydrogen (2 to 2
5 kg / cm 2 ). By treating the reaction product in the same manner as in Example 1-2, 1.74 g (yield: 82%) of 2-amino-4-fluorobenzoic acid was obtained.
【００２０】[0020]
【発明の効果】本発明に従えば、入手容易な４−フルオ
ロハロゲノ安息香酸から容易な方法でかつ高収率で２−
アミノ−４−フルオロ安息香酸を得ることができる。INDUSTRIAL APPLICABILITY According to the present invention, 2-fluorohalogenobenzoic acid, which is easily available, can be used in a simple manner and at high yield.
Amino-4-fluorobenzoic acid can be obtained.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 武田 勝彦 神奈川県藤沢市亀井野1431−30 (72)発明者 杉崎 徹 神奈川県茅ケ崎市本村３−17−１ (72)発明者 大橋 雅夫 神奈川県茅ケ崎市本村１−８−34 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Takeda 1431-30 Kameino, Fujisawa City, Kanagawa Prefecture (72) Inventor Toru Sugisaki 3-17-1 Motomura, Chigasaki City, Kanagawa Prefecture (72) Masao Ohashi Chigasaki, Kanagawa Prefecture 1-8-34 Ichimotomura
Claims (2)
するにあたり、２位が未置換でかつ少なくとも５位に塩
素原子あるいは臭素原子を有する４−フルオロハロゲノ
安息香酸をニトロ化せしめて４−フルオロ−２−ニトロ
ハロゲノ安息香酸とし、次いでこれを還元することを特
徴とする２−アミノ−４−フルオロ安息香酸の製造方
法。1. In producing 2-amino-4-fluorobenzoic acid, 4-fluorohalogenobenzoic acid which is unsubstituted at the 2-position and has a chlorine atom or a bromine atom at at least the 5-position is nitrated to give 4-amino-4-fluorobenzoic acid. A process for producing 2-amino-4-fluorobenzoic acid, which comprises producing fluoro-2-nitrohalogenobenzoic acid and then reducing the same.
ロロ−４−フルオロ安息香酸である、請求項１の製造方
法。2. The method according to claim 1, wherein the 4-fluorohalogenobenzoic acid is 5-chloro-4-fluorobenzoic acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27676591A JP3193421B2 (en) | 1991-09-27 | 1991-09-27 | Method for producing 2-amino-4-fluorobenzoic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27676591A JP3193421B2 (en) | 1991-09-27 | 1991-09-27 | Method for producing 2-amino-4-fluorobenzoic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0586000A true JPH0586000A (en) | 1993-04-06 |
| JP3193421B2 JP3193421B2 (en) | 2001-07-30 |
Family
ID=17574048
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27676591A Expired - Fee Related JP3193421B2 (en) | 1991-09-27 | 1991-09-27 | Method for producing 2-amino-4-fluorobenzoic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3193421B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003095417A1 (en) * | 2002-05-09 | 2003-11-20 | Miteni S.P.A. | Process for the manufacture of 4-fluoro-anthranilic acid |
| CN110294691A (en) * | 2019-08-11 | 2019-10-01 | 沈阳百傲化学有限公司 | The synthesis technology of 2- amino -3,5- dinitro cyanophenyl |
| CN113307740A (en) * | 2021-05-27 | 2021-08-27 | 中瀚(齐河县)生物医药科技有限公司 | Preparation method of 2-amino-4-fluorobenzoic acid |
-
1991
- 1991-09-27 JP JP27676591A patent/JP3193421B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003095417A1 (en) * | 2002-05-09 | 2003-11-20 | Miteni S.P.A. | Process for the manufacture of 4-fluoro-anthranilic acid |
| CN110294691A (en) * | 2019-08-11 | 2019-10-01 | 沈阳百傲化学有限公司 | The synthesis technology of 2- amino -3,5- dinitro cyanophenyl |
| CN113307740A (en) * | 2021-05-27 | 2021-08-27 | 中瀚(齐河县)生物医药科技有限公司 | Preparation method of 2-amino-4-fluorobenzoic acid |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3193421B2 (en) | 2001-07-30 |
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