JPH0581587B2 - - Google Patents
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- Publication number
- JPH0581587B2 JPH0581587B2 JP58245558A JP24555883A JPH0581587B2 JP H0581587 B2 JPH0581587 B2 JP H0581587B2 JP 58245558 A JP58245558 A JP 58245558A JP 24555883 A JP24555883 A JP 24555883A JP H0581587 B2 JPH0581587 B2 JP H0581587B2
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- Prior art keywords
- reaction
- present
- carbonyl compound
- group
- boron
- Prior art date
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- Heterocyclic Compounds Containing Sulfur Atoms (AREA)
- Quinoline Compounds (AREA)
- Plural Heterocyclic Compounds (AREA)
- Thiazole And Isothizaole Compounds (AREA)
- Hydrogenated Pyridines (AREA)
- Pyrrole Compounds (AREA)
- Indole Compounds (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Nitrogen- Or Sulfur-Containing Heterocyclic Ring Compounds With Rings Of Six Or More Members (AREA)
- Furan Compounds (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
- Pyridine Compounds (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
本発明は特定のカルボニル化合物と第１級アミ
ンとを三ハロゲン化ホウ素の存在下で反応させる
ことを特徴とする、シツフ塩基を製造する方法に
関する。
カルボニル化合物と第１級アミンとの縮合反応
は平衡反応であり、生成する水を除去することに
より、シツフ塩基の生成は進行することが知られ
ている。
しかし、上記の縮合反応を無触媒で行なつた場
合、比較的長い反応時間を要したり、生成するシ
ツフ塩基が低収率でしか得られない。特に、カル
ボニル化合物のカルボニル基や第１級アミンのア
ミノ基に近接した位置に嵩高い基が結合している
カルボニル化合物及び第１級アミンを用いた場合
には、上記の欠点が著しいものとなる。
このような欠点を改良するために、触媒を用い
る方法が研究され、塩化亜鉛や酢酸等を触媒とし
て用いることが提案されている。しかしながら、
このような触媒を用いても、前記の欠点は十分に
は改良され得ない。
本発明者らは、上記のような背景のもとにカル
ボニル化合物と第１級アミンとを反応させる方法
について研究を重ねた結果、触媒として三ハロゲ
ン化ホウ素を用いると上記反応の反応時間が短
く、しかも生成するシツフ塩基の収率も大きいこ
とを見い出し、本発明を完成させるに至つた。
一般式
The present invention relates to a method for producing a Schiff base, which is characterized by reacting a specific carbonyl compound and a primary amine in the presence of boron trihalide. It is known that the condensation reaction between a carbonyl compound and a primary amine is an equilibrium reaction, and that the production of Schiff's base proceeds by removing the produced water. However, when the above condensation reaction is carried out without a catalyst, a relatively long reaction time is required, and the Schiff base produced can only be obtained in a low yield. In particular, when carbonyl compounds and primary amines in which a bulky group is bonded to a position close to the carbonyl group of the carbonyl compound or the amino group of the primary amine are used, the above drawbacks become significant. . In order to improve these drawbacks, methods using catalysts have been studied, and the use of zinc chloride, acetic acid, etc. as catalysts has been proposed. however,
Even with the use of such catalysts, the aforementioned drawbacks cannot be sufficiently improved. Based on the above background, the present inventors have repeatedly researched a method for reacting carbonyl compounds and primary amines, and have found that using boron trihalide as a catalyst shortens the reaction time of the above reaction. Moreover, they discovered that the yield of the Schiff base produced was also high, leading to the completion of the present invention. general formula
【式】
（但し、R1とR2は、少なくとも一方がオルソ
位に置換基を有する複素環基であり、他が水素又
は有機基である）
で示されるカルボニル化合物と、
一般式
R3−NH2
（但し、R3は、オルソ位に置換基を有するア
リール基である）
で示される第１級アミンを
三ハロゲン化ホウ素の存在化に反応させること
を特徴とするシツフ塩基の製造方法。
本発明に於ける三ハロゲン化ホウ素は、前記特
定のカルボニル基とアミノ基との反応を短時間
に、しかも効率良く行なう触媒作用を有するもの
である。
本発明において、カルボニル化合物は、下記一
般式(1)で示されるものである。[Formula] (However, at least one of R 1 and R 2 is a heterocyclic group having a substituent at the ortho position, and the other is hydrogen or an organic group.) A carbonyl compound represented by the general formula R 3 − A method for producing a Schiff base, which comprises reacting a primary amine represented by NH 2 (wherein R 3 is an aryl group having a substituent at the ortho position) into the presence of boron trihalide. The boron trihalide used in the present invention has a catalytic action to carry out the reaction between the specific carbonyl group and the amino group in a short time and efficiently. In the present invention, the carbonyl compound is represented by the following general formula (1).
【式】
（但し、R1とR2は、少なくとも一方がオルソ
位に置換基を有する複素環基であり、他が水素又
は有機基である）
上記カルボニル化合物を具体的に例示すれば、
例えば、２−メチル−３−フルフラール、３−メ
トキシ−２−チオフエンアルデヒド、３−エトキ
シ−２−ピリジンアルデヒド、Ｎ−メチルピロー
ル−２−アルデヒド、２−メトキシメチル−３−
チオフエンアルデヒド、３−エチルチオフエン−
２−エチルケトン、４−メチル−１，２，５−オ
キサジアゾール−３−アルデヒド等が挙げられ
る。
一方、本発明で用いられる第１級アミンはR3
を有機基とするとき下記式(2)で示される。
R3−NH2 ……(2)
上記一般式(2)中のR3の有機基は、オルソ位に
置換基を有するアリール基又は複素環基である。
かかる第１級アミンを具体的に例示すれば、
２，６−ジメチルアニリン、２−メチル−６−エ
チルアニリン、２−メチル−６−メトキシアニリ
ン、２−エチル−６−メトキシアニリン、２−イ
ソプロピル−６−メチルアニリン、２−ｔ−ブチ
ル−６−メチルアニリン、２，６−ジクロロアニ
リン、２，６−ジニトロアニリン、２，４，６−
トリエチルアニリン３−シアノ−２−アミノチオ
フエン、１−アミノ−ナフタレン等が挙げられ
る。
上記に示した第１級アミンの中でも、R3が置
換アリール基又は置換複素環基であり、アミノ基
に対して少くとも１つのオルソ位に置換基を有す
る第１級アミン、具体的には例えば上記２，６−
ジメチルアニリン乃至１−アミノ−ナフタレンに
示したものについては、本発明が特に効果的に適
用される。
また、本発明の触媒である三ハロゲン化ホウ素
は公知な化合物であり、特に限定されず使用出来
る。好適に使用される三ハロゲン化ホウ素を例示
すると三フツ化ホウ素、三フツ化ホウ素エチルエ
ーテル、三塩化ホウ素、三臭化ホウ素、三ヨウ化
ホウ素等が好適である。就中、三フツ化ホウ素及
び三フツ化ホウ素エチルエーテルは、上記のカル
ボニル化合物と第１級アミンの反応時間を短く
し、しかも生成するシツフ塩基の収率を大きくす
るために、本発明で特に好ましく使用される。
前記本発明の反応を示せば、下記の通りであ
る。[Formula] (However, at least one of R 1 and R 2 is a heterocyclic group having a substituent at the ortho position, and the other is hydrogen or an organic group.) Specific examples of the above carbonyl compound include:
For example, 2-methyl-3-furfural, 3-methoxy-2-thiophenaldehyde, 3-ethoxy-2-pyridine aldehyde, N-methylpyrrole-2-aldehyde, 2-methoxymethyl-3-
Thiophenaldehyde, 3-ethylthiophene-
Examples include 2-ethylketone, 4-methyl-1,2,5-oxadiazole-3-aldehyde, and the like. On the other hand, the primary amine used in the present invention is R 3
When is an organic group, it is represented by the following formula (2). R 3 −NH 2 ...(2) The organic group of R 3 in the above general formula (2) is an aryl group or a heterocyclic group having a substituent at the ortho position. Specific examples of such primary amines include:
2,6-dimethylaniline, 2-methyl-6-ethylaniline, 2-methyl-6-methoxyaniline, 2-ethyl-6-methoxyaniline, 2-isopropyl-6-methylaniline, 2-t-butyl-6 -Methylaniline, 2,6-dichloroaniline, 2,6-dinitroaniline, 2,4,6-
Examples include triethylaniline, 3-cyano-2-aminothiophene, and 1-amino-naphthalene. Among the primary amines shown above, primary amines in which R 3 is a substituted aryl group or a substituted heterocyclic group and have a substituent at least one ortho position with respect to the amino group, specifically, For example, the above 2,6-
The present invention is particularly effectively applied to dimethylaniline to 1-amino-naphthalene. Further, boron trihalide, which is the catalyst of the present invention, is a known compound and can be used without particular limitation. Examples of boron trihalides that are preferably used include boron trifluoride, boron trifluoride ethyl ether, boron trichloride, boron tribromide, and boron triiodide. Among these, boron trifluoride and boron trifluoride ethyl ether are particularly used in the present invention in order to shorten the reaction time of the above-mentioned carbonyl compound and primary amine and to increase the yield of Schiff's base. Preferably used. The reaction of the present invention is as follows.
【化】
本発明により、触媒として三ハロゲン化ホウ素
を用い、カルボニル化合物と第１級アミンからシ
ツフ塩基を製造する際、通常は不活性有機溶媒を
用いるのが好ましい。該不活性有機溶媒として
は、あらゆる種類の不活性有機溶媒が適用でき、
特に限定されるものではないが、特に水と共沸す
る不活性有機溶媒であるベンゼン、トルエン、キ
シレン等が好適に使用される。本発明の実施にお
いて、反応操作の手順として、不活性有機溶媒中
へのカルボニル化合物、第１級アミン及び三ハロ
ゲン化ホウ素の添加順序は特に限定されるもので
はないが、好ましくは、不活性溶媒中にカルボニ
ル化合物と第１級アミンを加えて加熱し、還流が
始まつた後に三ハロゲン化ホウ素を添加するのが
良い。またカルボニル化合物と第１級アミンのモ
ル比は特に限定されるものではないが、一般には
１：0.1〜１：10、好ましくは１：0.3〜１：３の
範囲から選べばよい。好適には、単離操作上、
１：１の割合で使用するのが良い。また、触媒は
カルボニル化合物に対して0.1〜10.0重量パーセ
ント、好ましくは0.5〜2.0重量パーセントの範囲
から選ばれる。更にまた、カルボニル化合物と不
活性有機溶媒の重量比は一般に１：２〜１：20、
好ましくは１：３〜１：10の範囲から選べばよ
い。本発明の反応における反応温度は限定され
ず、広い温度範囲で選びうるが、一般には50〜
180℃、好ましくは80〜150℃の範囲から選ぶと良
い。
本発明で得られるシツフ塩基の精製方法は、特
に限定されるものではないが、不活性有機溶媒を
除去すると触媒である三ハロゲン化ホウ素をも除
去できるので、単に常圧、減圧、もしくは真空蒸
留を行なえば良く、必要に応じて再結晶、または
クロマトグラフによる精製方法を用いることも出
来る。
本発明方法により得られるシツフ塩基は、例え
ば、殺菌剤、殺虫剤、除草剤の農薬あるいは医薬
品、及び、各種の農薬原料、医薬品原料、ゴムの
老化防止剤、ならびに液晶などに有用である。
以上の説明で明らかなように本発明によれば、
前記した特定のカルボニル化合物と第１級アミン
との反応時間が短縮でき、しかも生成するシツフ
塩基を収率良く得ることができる。即ち、カルボ
ニル基やアミノ基に近接した位置に嵩高い基を有
するものを使用した場合、上記の効果は十分に発
揮出来る大きな利点を有する。しかも、本発明で
使用する三ハロゲン化ホウ素は、反応終了後に溶
媒と共に留去するだけで除去可能であるため、反
応終了後の生成物の精製が極めて容易に行なえ
る。従つて、本発明は、工業的にも優れた利点を
有するものである。
以下に、本発明を具体的に説明するために実施
例を挙げるが、本発明はこれらの実施例に限定さ
れるものではない。
実施例 １
共沸脱水装置を備えた200mlの三つ口フラスコ
に、２−エチルカルボニル−５−メチルフラン10
ｇ（0.073mole）、２，６−ジエチルアニリン10.8
ｇ（0.073mole）とベンゼン100mlを加え、加熱
した。還流し始めてから、反応溶液に0.20mlの三
フツ化ホウ素エチルエーテルを加え、３時間加熱
還流した。仕込みモル数に対応した生成水を確認
した後、反応溶液を室温まで冷却した。溶媒及び
三フツ化ホウ素エチルエーテル留去した後、残渣
を真空蒸留し、沸点117℃／0.55mmＨｇの下記の
構造式で示されるシツフ塩基、16.7ｇ
（0.062mole）が、淡黄色液体として得られた。
収率は85％であつた。According to the present invention, when a Schiff base is produced from a carbonyl compound and a primary amine using boron trihalide as a catalyst, it is usually preferable to use an inert organic solvent. As the inert organic solvent, all kinds of inert organic solvents can be applied,
Although not particularly limited, inert organic solvents that are azeotropic with water, such as benzene, toluene, and xylene, are particularly preferably used. In carrying out the present invention, the order of addition of the carbonyl compound, primary amine, and boron trihalide into an inert organic solvent is not particularly limited as a reaction procedure, but preferably It is preferable to add a carbonyl compound and a primary amine therein, heat the mixture, and add boron trihalide after reflux starts. Further, the molar ratio of the carbonyl compound to the primary amine is not particularly limited, but it may be selected generally from the range of 1:0.1 to 1:10, preferably from 1:0.3 to 1:3. Preferably, for isolation operations,
It is best to use a ratio of 1:1. Further, the catalyst is selected from the range of 0.1 to 10.0 weight percent, preferably 0.5 to 2.0 weight percent based on the carbonyl compound. Furthermore, the weight ratio of the carbonyl compound and the inert organic solvent is generally 1:2 to 1:20,
Preferably, the ratio may be selected from the range of 1:3 to 1:10. The reaction temperature in the reaction of the present invention is not limited and can be selected within a wide temperature range, but generally
The temperature should be selected from the range of 180℃, preferably 80 to 150℃. The method for purifying Schiff's base obtained in the present invention is not particularly limited, but since the catalyst boron trihalide can also be removed by removing the inert organic solvent, simple distillation at normal pressure, reduced pressure, or vacuum distillation can be used. If necessary, recrystallization or purification by chromatography may be used. The Schiff base obtained by the method of the present invention is useful, for example, in pesticides or pharmaceuticals such as bactericides, insecticides, and herbicides, as well as various agricultural chemical raw materials, pharmaceutical raw materials, antiaging agents for rubber, and liquid crystals. As is clear from the above description, according to the present invention,
The reaction time between the above-mentioned specific carbonyl compound and the primary amine can be shortened, and the resulting Schiff base can be obtained in good yield. That is, when one having a bulky group in the vicinity of a carbonyl group or an amino group is used, there is a great advantage that the above effects can be fully exhibited. Moreover, since the boron trihalide used in the present invention can be removed by simply distilling it off together with the solvent after the reaction is completed, the product after the reaction can be purified very easily. Therefore, the present invention has excellent industrial advantages. Examples are given below to specifically explain the present invention, but the present invention is not limited to these Examples. Example 1 In a 200 ml three-necked flask equipped with an azeotropic dehydration device, 10 ml of 2-ethylcarbonyl-5-methylfuran was added.
g (0.073mole), 2,6-diethylaniline 10.8
g (0.073 mole) and 100 ml of benzene were added and heated. After starting to reflux, 0.20 ml of boron trifluoride ethyl ether was added to the reaction solution, and the mixture was heated under reflux for 3 hours. After confirming the amount of water produced corresponding to the number of moles charged, the reaction solution was cooled to room temperature. After distilling off the solvent and boron trifluoride ethyl ether, the residue was distilled under vacuum to obtain 16.7 g of Schiff's base having a boiling point of 117°C/0.55 mmHg and having the following structural formula.
(0.062 mole) was obtained as a pale yellow liquid.
The yield was 85%.
【化】
比較例 １
実施例１に於いて、三フツ化ホウ素エチルエー
テルを添加せず、ベンゼン100mlに代えキシレン
100mlを用い反応を３日間実施した以外は実施例
１と同様に実施した。その結果、実施例１と同じ
シツフ塩基を収率5.1％（収量：1.0ｇ
（0.0037mole））を得た。
比較例 ２
実施例１に於いて三フツ化ホウ素エチルエーテ
ルの代りに塩化亜鉛0.5ｇ（0.0037mole）を用い、
反応を２日間行つた以外は実施例１と同様に実施
した。その結果実施例１と同じシツフ塩基を収率
20.3％（収量4.0ｇ（0.015mole））で得た。
比較例 ３
実施例１に於いて三フツ化ホウ素エチルエーテ
ルの代りに酢酸0.5ｇ（0.0083mole）を加え、反
応を６時間行つた以外は実施例１と同様に実施し
た。その結果実施例１と同じシツフ塩基を収率
19.4％（収量3.8ｇ（0.014mole））を得た。
比較例 ４
実施例１において三フツ化ホウ素エチルエーテ
ルの替わりに三塩化リン0.5ｇ（0.0036mole）を
加え、反応を６時間行つた以外は実施例１と同様
に実施した。
その結果、反応液は黒色化し、タール分がフラ
スコ壁面に付着した。溶液を水洗した後、有機層
を乾燥、濃縮した。残査を真空蒸留し、実施例１
と同様のシツフ塩基0.88ｇ（0.0033mole）を得
た。収率は4.5％であつた。
実施例２、比較例４Comparative Example 1 In Example 1, boron trifluoride ethyl ether was not added and xylene was used instead of 100 ml of benzene.
The reaction was carried out in the same manner as in Example 1 except that 100 ml was used and the reaction was carried out for 3 days. As a result, the same Schiff base as in Example 1 was obtained in a yield of 5.1% (yield: 1.0 g
(0.0037mole)) was obtained. Comparative Example 2 In Example 1, 0.5 g (0.0037 mole) of zinc chloride was used instead of boron trifluoride ethyl ether,
The same procedure as in Example 1 was carried out except that the reaction was carried out for 2 days. As a result, the same Schiff base as in Example 1 was obtained.
20.3% (yield 4.0 g (0.015 mole)). Comparative Example 3 The same procedure as in Example 1 was carried out except that 0.5 g (0.0083 mole) of acetic acid was added instead of boron trifluoride ethyl ether and the reaction was carried out for 6 hours. As a result, the same Schiff base as in Example 1 was obtained.
19.4% (yield 3.8 g (0.014 mole)) was obtained. Comparative Example 4 The same procedure as in Example 1 was carried out except that 0.5 g (0.0036 mole) of phosphorus trichloride was added instead of boron trifluoride ethyl ether and the reaction was carried out for 6 hours. As a result, the reaction solution turned black and tar adhered to the flask wall. After washing the solution with water, the organic layer was dried and concentrated. The residue was vacuum distilled and Example 1
0.88 g (0.0033 mole) of Schiff's base similar to the above was obtained. The yield was 4.5%. Example 2, Comparative Example 4
【化】 と[ka] and
【化】
とを表１に示す三ハロゲン化ホウ素が存在するベ
ンゼン溶媒中、加熱還流下に１時間反応を行つ
た。反応中の生成中は共沸脱水装置を用いて除去
した。その結果、The reaction was carried out under heating under reflux for 1 hour in a benzene solvent in which boron trihalide shown in Table 1 was present. The product produced during the reaction was removed using an azeotropic dehydrator. the result,
【化】 のシツフ塩基を表１に示す収率で得た。[ka] Schiff's base was obtained in the yield shown in Table 1.
【表】
実施例 ３
表２に示すカルボニル化合物を0.10moleと表
２に示す第１級アミンを0.1mole用い、三フツ化
ホウ素エチルエーテル（0.5m mole）を触媒とし
表２に示す反応時間、加熱還流した以外は実施例
１と同様に実施した。その結果表２に示すシツフ
塩基を表２に示す収率で得た。[Table] Example 3 Using 0.10 mole of the carbonyl compound shown in Table 2 and 0.1 mole of the primary amine shown in Table 2, using boron trifluoride ethyl ether (0.5 mmole) as a catalyst, the reaction time shown in Table 2, The same procedure as in Example 1 was carried out except that heating was carried out under reflux. As a result, the Schiff base shown in Table 2 was obtained in the yield shown in Table 2.
【表】【table】
【表】【table】
【表】【table】
Claims (1)
位に置換基を有する複素環基であり、他が水素又
は有機基である） で示されるカルボニル化合物と、 一般式 R3−NH2 （但し、R3は、オルソ位に置換基を有するア
リール基又は複素環基である） で示される第１級アミンを 三ハロゲン化ホウ素の存在化に反応させること
を特徴とするシツフ塩基の製造方法。[Claims] 1 General formula [Formula] (However, at least one of R 1 and R 2 is a heterocyclic group having a substituent at the ortho position, and the other is hydrogen or an organic group.) A carbonyl compound and a primary amine represented by the general formula R 3 -NH 2 (wherein R 3 is an aryl group or a heterocyclic group having a substituent at the ortho position) are combined into the presence of boron trihalide. A method for producing a Schiff base, which comprises reacting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58245558A JPS60142929A (en) | 1983-12-28 | 1983-12-28 | Preparation of schiff base |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58245558A JPS60142929A (en) | 1983-12-28 | 1983-12-28 | Preparation of schiff base |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60142929A JPS60142929A (en) | 1985-07-29 |
| JPH0581587B2 true JPH0581587B2 (en) | 1993-11-15 |
Family
ID=17135487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58245558A Granted JPS60142929A (en) | 1983-12-28 | 1983-12-28 | Preparation of schiff base |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60142929A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105503763B (en) | 2014-10-17 | 2020-11-03 | 上海中科康润新材料科技有限公司 | Polyolefin oil catalyst and its application |
-
1983
- 1983-12-28 JP JP58245558A patent/JPS60142929A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60142929A (en) | 1985-07-29 |
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