JP5000031B2 - Method for producing aromatic-o-dialdehyde compound - Google Patents

Description

【０００８】
（式中、Ｒ_１はアルキル基、水酸基、アルコキシ基、ニトロ基、シアノ基、ハロゲン原子またはカルボキシル基を示し、ｎは０〜４の整数を示し、ｎが２以上の場合、Ｒ_１は互いに同じでも異なっていてもよい。Ｘはハロゲン原子を示す。）
及び
（２）水以外の溶媒は実質的に含有しない（１）項記載の芳香族−ｏ−ジアルデヒド化合物の製造方法を提供するものである。
本発明において過剰量の水が存在するとき、反応に必要な化学量論量より多い水は、その余剰分が溶媒として作用する。
【０００９】
【発明の実施の形態】
以下、本発明をさらに詳細に説明する。
上記一般式（１）において、Ｒ₁ について説明すると、アルキル基は好ましくは炭素数１〜５のもの（例えば、メチル、エチル、プロピル、アミル）、アルコキシ基は好ましくは炭素数１〜５のもの（例えば、メトキシ、エトキシ、プロポキシ、ブトキシ）、ハロゲン原子は塩素、臭素、ヨウ素またはフッ素原子を表わす。ここで、上記のアルキル基及びアルコキシ基はハロゲン原子（塩素、臭素、フッ素原子など）、水酸基などでさらに置換されているものも包含する。ｎは好ましくは０又は１〜２である。Ｘのハロゲン原子としては、塩素、臭素またはヨウ素原子などがあげられ、好ましくは塩素または臭素原子である。特に好ましくはｎは０又は１であり、Ｒ₁ は低級アルキル基、ハロゲン原子、シアノ基である。
【００１０】
本発明に用いられるα，α，α’，α’−テトラハロゲノ−ｏ−キシレン化合物は、それ自体公知であり、通常の技術によって製造することができる。例えば、α，α，α’，α’−テトラクロロ−ｏ−キシレンは、ｏ−キシレンを紫外線照射下で塩素化することにより製造される。得られたα，α，α’，α’−テトラクロロ−ｏ−キシレンは、そのまま使用してもよいが、通常はトルエンまたはキシレン等の溶媒により再結晶して使用される。
【００１１】
本発明で実施される加水分解反応に使用される水は、通常の水であれば特に制限はないが、鉄錆等の濁りや汚れがある場合は濾過して使用することが好ましい。
本発明において加水分解反応に使用する水は、重量比で、α，α，α’，α’−テトラハロゲノ−ｏ−キシレン化合物に対して４倍量〜２０倍量である。この水の量が上記のように過剰でないと、触媒なしでは反応速度が遅く、また、反応で発生する塩化水素により反応液中の塩酸濃度が高くなり不純物のフタリド類の副生が多くなる。その生成機構は明らかでないが、芳香族−ｏ−ジアルデヒド化合物は濃塩酸の存在下、加熱によりフタリド類に変化し、特に塩酸濃度が１５％を越えるとその反応が著しく促進される。
【００１２】
加水分解に使用する水の添加法については特に制限はない。反応開始時に全量加えてもよいし、反応途中に一部を分けて添加してもよい。反応方法についても特に制限はなく、回分式もしくは連続式のいずれも採用することができる。また、反応は常圧又は加圧のいずれでも実施できる。
本発明においては、反応成分及び反応溶媒として水を用いるが、それ以外の反応試剤、例えば濃硫酸又は塩化亜鉛のようなルイス酸を用いない。
また、本発明においては水以外の溶媒を実質的に含まず、１０％以下の量であることが好ましく、全く含まないのが特に好ましい。水以外の含んでいてもよい溶媒としては、反応に悪影響を及ぼさないものであればどのような溶媒でもよいが、例としてトルエン、キシレン、クロロベンゼン等を挙げることができる。
【００１３】
本発明における反応温度は加水分解反応が進行する温度であれば特に制限はないが、通常は８０℃以上、好ましくは水の還流温度で行われ、この還流温度は反応が常圧で実施される場合は９９〜１０１℃の範囲であり、加圧の場合は圧力に応じて反応温度が高くなる。
反応時間は反応温度、水の量などにより変わるが、通常は２４時間で十分であり、好ましくは８〜２４時間である。
【００１４】
前述したように、この加水分解により生成するハロゲン化水素はフタリド類のような好ましくない不純物の副生を促進させる。そのため、副生した酸を中和しながら反応させることも可能である。
この場合に用いる中和剤としては、アルカリ金属塩又はアルカリ土類金属塩が好ましく、具体的には炭酸水素ナトリウムや炭酸カルシウム等を例として挙げることができる。また、反応で使用した水は、目的物である芳香族−ｏ−ジアルデヒド化合物を有機溶媒で抽出した後、例えば水酸化ナトリウムのようなアルカリで中和して、再度次の加水分解反応に使用することもできる。
【００１５】
加水分解反応により生成した芳香族−ｏ−ジアルデヒド化合物の分離は、水と混和しない有機溶媒、例えばトルエン、キシレン、クロロベンゼン等で抽出し、溶媒を回収することにより行うことができる。通常はそのままでも十分な純度を有していて、製品となりうるが、さらに高純度品を要求される場合は再結晶又は蒸留により精製してもよい。
本発明において反応は開放系でも実施可能であるが、芳香族−ｏ−ジアルデヒド化合物の酸化反応を抑制するため、例えば窒素、アルゴン等の不活性ガスの雰囲気下で実施することが望ましい。
このような方法で得られた芳香族−ｏ−ジアルデヒド化合物は、低級脂肪酸等の有機物を全く使用しておらず、水だけを反応試剤及び反応溶媒として使用しているため、特別な精製工程を経由しないでも十分に高純度であり、安定性にも優れている。
【００１６】
【実施例】
以下、実施例に基づき本発明を具体的に説明するが、本発明はこれら実施例により限定されるものではない。
実施例１
温度計、還流冷却器、攪拌機を備えた５００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン１２．２ｇと水２４４ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で８時間攪拌し、冷却後、反応液をエーテルで抽出し、ガスクロマトグラフィーで分析した。その結果、原料のα，α，α’，α’−テトラクロロ−ｏ−キシレンは完全に消失し、ｏ−フタルアルデヒドの純度は９９．３％であった。
【００１７】
実施例２
温度計、還流冷却器、攪拌機を備えた５００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン２４．４ｇと水２４４ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で１６時間攪拌し、冷却後、反応液をエーテルで抽出し、ガスクロマトグラフィーで分析した。その結果、原料のα，α，α’，α’−テトラクロロ−ｏ−キシレンは完全に消失し、ｏ−フタルアルデヒドの純度は９８．４％であった。
【００１８】
実施例３
温度計、還流冷却器、攪拌機を備えた２００ｍｌ容の４径フラスコにα，α，α’，α’−テトラブロモ−ｏ−キシレン１６．９ｇと水１６９ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で１２時間攪拌し、冷却後、反応液をエーテルで抽出し、ガスクロマトグラフィーで分析した。その結果、原料のα，α，α’，α’−テトラブロモ−ｏ−キシレンは完全に消失し、ｏ−フタルアルデヒドの純度は９９．６％であった。
【００１９】
実施例４
温度計、還流冷却器、攪拌機を備えた１リットル容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン３９．０ｇと水７８０ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で８時間攪拌し、反応終了後、室温まで冷却した。その後、反応液を２リットル容の分液ロートに移し、２００ｍｌのトルエンで２回、１００ｍｌのトルエンで１回、抽出した。
トルエン層は水洗後、エバポレーター及び真空ポンプで濃縮してｏ−フタルアルデヒド２０．３ｇを得た。これは、仕込み原料に対して９４．７％の収率であった。このようにして得たｏ−フタルアルデヒドをガスクロマトグラフィーで分析した結果、純度は９９．５％であった。
【００２０】
実施例５
温度計、還流冷却器、攪拌機を備えた１リットル容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン３９．０ｇと水７８０ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で８時間攪拌し、反応終了後、室温まで冷却した。その後、反応液を２リットル容の分液ロートに移し、２００ｍｌのクロロベンゼンで２回、１００ｍｌのクロロベンゼンで１回、抽出した。
水層は水酸化ナトリウムで中和した後、再度１リットル容の４径フラスコに移し、α，α，α’，α’−テトラクロロ−ｏ−キシレン３９．０ｇを加えて窒素流通下、再びオイルバスにより還流温度（１００〜１０１℃）まで加熱した（繰り返し１回目）。この状態で１０時間攪拌し、反応終了後、室温まで冷却した。その後、反応液を２リットル容の分液ロートに移し、前記と同様クロロベンゼンで３回抽出した。
水層は水酸化ナトリウムで中和した後、再度１リットル容の４径フラスコに移し、α，α，α’，α’−テトラクロロ−ｏ−キシレン３９．０ｇを加えて窒素流通下、再びオイルバスにより還流温度（１００〜１０１℃）まで加熱した（繰り返し２回目）。前記と同様、１４時間攪拌し、反応終了後、室温まで冷却した。クロロベンゼンで３回抽出し、３回分のクロロベンゼンを合わせて水洗した。
クロロベンゼン層をエバポレーター及び真空ポンプで濃縮してｏ−フタルアルデヒド６１．３ｇを得た。これは、仕込み原料に対して９５．３％の収率であった。このようにして得たｏ−フタルアルデヒドをガスクロマトグラフィーで分析した結果、純度は９９．１％であった。
【００２１】
実施例６
温度計、還流冷却器、攪拌機を備えた３リットル容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン２４４ｇと水２４４０ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で１６時間攪拌し、反応終了後、室温まで冷却した。その後、反応液を５リットル容の分液ロートに移し、４００ｍｌのクロロベンゼンで２回、２００ｍｌのクロロベンゼンで１回、抽出した。
エバポレーターでクロロベンゼンを回収した後、内径１５ｍｍのガラス管に５ｍｍのガラスヘリッパクを１５ｃｍ充填した精留塔で減圧蒸留し、１１２．２ｇの精製ｏ−フタルアルデヒドを得た。これは、仕込み原料に対して８３．７％の収率であり、ガスクロマトグラフィーで分析した結果、ｏ−フタルアルデヒドの純度は９９．９％であった。
【００２２】
実施例７
温度計、還流冷却器、攪拌機を備えた２００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン１４．６ｇ及び炭酸カルシウム６．０ｇと水１４６ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。この状態で２４時間攪拌し、冷却後、反応液をエーテルで抽出し、ガスクロマトグラフィーで分析した。その結果、原料のα，α，α’，α’−テトラクロロ−ｏ−キシレンは完全に消失し、ｏ−フタルアルデヒドの純度は９９．２％であった。
【００２３】
比較例１
温度計、還流冷却器、攪拌機を備えた５００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン２４．４ｇと９０％硫酸２４４ｇを仕込み、窒素流通下、オイルバスにより８０℃まで加熱した。
この状態で２時間攪拌したところ、反応液が黒色となり、エーテル不溶物が多量に副生し、ｏ−フタルアルデヒドはほとんど生成していなかった。
【００２４】
比較例２
温度計、還流冷却器、攪拌機、水滴下装置を備えた１００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン１４．４ｇと塩化亜鉛０．７ｇを仕込み、窒素流通下、オイルバスにより１２０℃まで加熱した。昇温中に塩化水素の発生を伴いながらα，α，α’，α’−テトラクロロ−ｏ−キシレンの重合が起こったため、水を滴下する前に中断した。
【００２５】
比較例３
温度計、還流冷却器、攪拌機を備えた２００ｍｌ容の４径フラスコにα，α，α’，α’−テトラクロロ−ｏ−キシレン３６．６ｇと水１０９．８ｇとを仕込み、窒素流通下、オイルバスにより還流温度（９９〜１０１℃）まで加熱した。還流状態で４０時間攪拌し、冷却後、反応液をエーテルで抽出し、ガスクロマトグラフィーで分析した。その結果、原料のα，α，α’，α’−テトラクロロ−ｏ−キシレンが３．４％残存し、ｏ−フタルアルデヒドが６３．３％、フタリドが２９．８％生成していた。反応終了時点の塩酸濃度は、計算上１６．２％であった。
【００２６】
【発明の効果】
本発明の製造方法によれば、α，α，α’，α’−テトラハロゲノ−ｏ−キシレン化合物を出発原料とし、過剰な水を反応試剤及び反応溶媒として使用するため、副反応が抑制され、高収率かつ高純度で芳香族−ｏ−ジアルデヒド化合物を製造することができる。
さらに、原料以外の有機溶媒および有機酸類をまったく必要としないため、それらの回収作業が不必要であり、本発明方法は、経済性においても、また作業性においても優れ、工業的に実施する方法として好適である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an aromatic-o-dialdehyde compound. Aromatic o-dialdehyde compounds are compounds widely used as raw materials and intermediates for agricultural drugs and chemical products, and are particularly useful as industrial fungicides.
[0002]
[Prior art]
As a method for producing aromatic-o-dialdehydes, for example, a method in which a corresponding carboxylic acid derivative is reduced with lithium aluminum hydride to produce o-phthalaldehyde, and o-phthalalcohol is oxidized to o- Although methods for producing phthalaldehyde are known, neither method is suitable for industrial implementation because expensive reaction reagents and raw materials are used.
[0003]
A method of hydrolyzing α, α, α ′, α′-tetrabromo-o-xylenes with a stoichiometric amount of water is described in, for example, Org. Synth. , IV, 807 (1963). Although this method is a method of hydrolysis using 50% ethanol and potassium oxalate, it is economical because potassium oxalate and a large excess of ethanol, which are not inexpensive, must be used, and the reaction time is long. This is not an advantageous method.
Known methods for producing aromatic aldehydes by hydrolysis of dihalogenomethylbenzenes include a method of reacting with water in the presence of a Lewis acid such as zinc chloride and iron chloride, and a method of heating with concentrated sulfuric acid. However, in the case of α, α, α ′, α′-tetrahalogeno-o-xylenes, each dihalogenomethyl group is present at the o-position of the aromatic ring, so that it becomes very unstable, and the Lewis acid has a catalytic amount. When it is added and heated, it immediately polymerizes with generation of hydrogen halide. Similarly, when heated with concentrated sulfuric acid, the reaction solution turns black and almost no desired product can be obtained. Therefore, various ideas have been devised when hydrolyzing α, α, α ′, α′-tetrahalogeno-o-xylenes.
[0004]
Further, in US Pat. No. 5,107,032, o-phthalaldehyde is added by adding α, α, α ′, α′-tetrachloro-o-xylene in an acetic acid solvent and an aqueous sodium hydroxide solution little by little. It has gained. However, since a large excess of acetic acid is used in this method, the treatment after the reaction becomes complicated, and it is not an economically preferable method. Furthermore, in order to obtain o-phthalaldehyde with a relatively high yield, it is necessary to carry out a reaction under pressure by an autoclave, and it cannot be said that this is a general production method suitable for industrial implementation.
Japanese Patent Laid-Open No. 9-124538 discloses α, α, α ′, α′-tetrabromo-o-xylene, an alkali metal salt or an alkaline earth metal salt as a neutralizing agent, a phase transfer catalyst and a water-soluble catalyst. A process for hydrolysis in the presence of an alcohol or ether solvent is described. However, since this method also uses a water-soluble solvent having a boiling point higher than that of water, complicated processing such as solvent recovery is necessary, and this method is not industrially preferable. In a method using a lower fatty acid, an alcohol or an ether solvent other than such raw materials, they may be mixed into the target aromatic-o-dialdehyde, which may cause a decrease in stability and purity.
[0005]
[Problems to be solved by the invention]
In view of these facts, the object of the present invention is to hydrolyze an α, α, α ′, α′-tetrahalogeno-o-xylene compound to obtain a corresponding aromatic-o-dialdehyde compound in a high yield. It is to provide a method that can be manufactured at low cost.
Another object of the present invention is to provide a method capable of producing a desired aromatic-o-dialdehyde compound with high purity without suppressing side reactions and without performing a special purification step.
[0006]
[Means for Solving the Problems]
In order to overcome the drawbacks of the conventional methods described above, the present inventor has conducted extensive studies on a method for producing an aromatic-o-dialdehyde compound, and as a result, α, α, α ′, α′-tetrahalogeno-o-xylene. Aromatic-o-dialdehyde compounds are produced in high yield, high purity and at low cost by hydrolyzing the compounds in the presence of a large excess of water without using Lewis acids or phase transfer catalysts. Based on this finding, the present inventors have made the present invention. That is, the present invention
(1) Reactions other than these in the presence of 4 to 20 times the amount of water by weight of the α, α, α ′, α′-tetrahalogeno-o-xylene compound represented by the general formula (1) A process for producing an aromatic-o-dialdehyde compound, characterized by hydrolysis without using a reagent;
General formula (1)
[0007]
[Chemical formula 2]

[0008]
(Wherein R ₁ represents an alkyl group, a hydroxyl group, an alkoxy group, a nitro group, a cyano group, a halogen atom or a carboxyl group, n represents an integer of 0 to 4, and when n is 2 or more, R ₁ They may be the same or different, and X represents a halogen atom.)
And ( 2 ) A method for producing an aromatic-o-dialdehyde compound according to (1), which contains substantially no solvent other than water.
In the present invention, when an excessive amount of water is present, the excess amount of water that exceeds the stoichiometric amount required for the reaction acts as a solvent.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
In the general formula (1), R ₁ will be described. The alkyl group preferably has 1 to 5 carbon atoms (for example, methyl, ethyl, propyl, amyl), and the alkoxy group preferably has 1 to 5 carbon atoms. (For example, methoxy, ethoxy, propoxy, butoxy), a halogen atom represents a chlorine, bromine, iodine or fluorine atom. Here, the alkyl group and the alkoxy group include those further substituted with a halogen atom (chlorine, bromine, fluorine atom, etc.), a hydroxyl group or the like. n is preferably 0 or 1-2. Examples of the halogen atom for X include chlorine, bromine and iodine atoms, with chlorine and bromine atoms being preferred. Particularly preferably, n is 0 or 1, and R ₁ is a lower alkyl group, a halogen atom or a cyano group.
[0010]
The α, α, α ′, α′-tetrahalogeno-o-xylene compounds used in the present invention are known per se and can be produced by ordinary techniques. For example, α, α, α ′, α′-tetrachloro-o-xylene is produced by chlorinating o-xylene under ultraviolet irradiation. The obtained α, α, α ′, α′-tetrachloro-o-xylene may be used as it is, but is usually recrystallized with a solvent such as toluene or xylene.
[0011]
The water used in the hydrolysis reaction carried out in the present invention is not particularly limited as long as it is ordinary water. However, when there is turbidity or dirt such as iron rust, it is preferably filtered before use.
The water used for the hydrolysis reaction in the present invention is 4 to 20 times by weight with respect to the α, α, α ′, α′-tetrahalogeno-o-xylene compound. If the amount of water is not excessive as described above, the reaction rate is slow without a catalyst, and the concentration of hydrochloric acid in the reaction solution is increased by hydrogen chloride generated by the reaction, and impurities phthalides are produced as a by-product. Although the formation mechanism is not clear, the aromatic-o-dialdehyde compound is changed to phthalides by heating in the presence of concentrated hydrochloric acid, and the reaction is remarkably accelerated particularly when the hydrochloric acid concentration exceeds 15% .
[0012]
There is no restriction | limiting in particular about the addition method of the water used for a hydrolysis. The whole amount may be added at the start of the reaction, or a part thereof may be added during the reaction. There is no restriction | limiting in particular also about the reaction method, Either a batch type or a continuous type can be employ | adopted. In addition, the reaction can be carried out at normal pressure or increased pressure.
In the present invention, water is used as reaction components and reaction solvent, no use reactants otherwise, for example, concentrated sulfuric acid or a Lewis acid such as zinc chloride.
Further, in the present invention substantially free of solvents other than water, preferably in an amount of 10% or less, not particularly preferred that it contains no. As the solvent which may be contained other than water, any solvent may be used as long as it does not adversely influence the reaction. Examples thereof include toluene, xylene, chlorobenzene and the like.
[0013]
The reaction temperature in the present invention is not particularly limited as long as the hydrolysis reaction proceeds. Usually, the reaction temperature is 80 ° C. or higher, preferably at the reflux temperature of water, and the reflux is performed at normal pressure. In the case of 99 to 101 ° C, the reaction temperature increases in accordance with the pressure in the case of pressurization.
The reaction time varies depending on the reaction temperature, the amount of water, etc., but usually 24 hours is sufficient, and preferably 8 to 24 hours.
[0014]
As described above, the hydrogen halide produced by the hydrolysis promotes by-product formation of undesirable impurities such as phthalides. Therefore, it is possible to react while neutralizing the by-produced acid.
The neutralizing agent used in this case is preferably an alkali metal salt or an alkaline earth metal salt, and specific examples thereof include sodium hydrogen carbonate and calcium carbonate. In addition, the water used in the reaction is extracted with the target aromatic-o-dialdehyde compound with an organic solvent, then neutralized with an alkali such as sodium hydroxide, and again subjected to the next hydrolysis reaction. It can also be used.
[0015]
Separation of the aromatic-o-dialdehyde compound produced by the hydrolysis reaction can be performed by extracting with an organic solvent immiscible with water, such as toluene, xylene, chlorobenzene, etc., and recovering the solvent. Usually, it has sufficient purity even if it is as it is, and can be a product, but if a higher purity product is required, it may be purified by recrystallization or distillation.
Although the reaction can be carried out in an open system in the present invention, it is desirable to carry out in an atmosphere of an inert gas such as nitrogen or argon in order to suppress the oxidation reaction of the aromatic-o-dialdehyde compound.
The aromatic-o-dialdehyde compound obtained by such a method does not use organic substances such as lower fatty acids at all, and uses only water as a reaction reagent and a reaction solvent. Even if it does not go through, it is sufficiently high purity and excellent in stability.
[0016]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited by these Examples.
Example 1
A 500 ml 4-diameter flask equipped with a thermometer, reflux condenser, and stirrer was charged with 12.2 g of α, α, α ′, α′-tetrachloro-o-xylene and 244 g of water, and an oil bath under nitrogen flow To reflux temperature (99-101 ° C.). After stirring in this state for 8 hours and cooling, the reaction solution was extracted with ether and analyzed by gas chromatography. As a result, the raw material α, α, α ′, α′-tetrachloro-o-xylene disappeared completely, and the purity of o-phthalaldehyde was 99.3%.
[0017]
Example 2
Α, α, α ′, α′-Tetrachloro-o-xylene 24.4 g and water 244 g were charged into a 500 ml 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. To reflux temperature (99-101 ° C.). After stirring in this state for 16 hours and cooling, the reaction solution was extracted with ether and analyzed by gas chromatography. As a result, the raw material α, α, α ′, α′-tetrachloro-o-xylene disappeared completely, and the purity of o-phthalaldehyde was 98.4%.
[0018]
Example 3
Α, α, α ′, α′-Tetrabromo-o-xylene (16.9 g) and water (169 g) were charged into a 200 ml 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. Heated to reflux temperature (99-101 ° C.). After stirring in this state for 12 hours and cooling, the reaction solution was extracted with ether and analyzed by gas chromatography. As a result, the raw material α, α, α ′, α′-tetrabromo-o-xylene disappeared completely, and the purity of o-phthalaldehyde was 99.6%.
[0019]
Example 4
Α, α, α ′, α′-Tetrachloro-o-xylene 39.0 g and water 780 g were charged into a 1 liter 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. Heated to reflux temperature (99-101 ° C.) by bath. The mixture was stirred for 8 hours in this state, and cooled to room temperature after completion of the reaction. Thereafter, the reaction solution was transferred to a 2 liter separatory funnel and extracted twice with 200 ml of toluene and once with 100 ml of toluene.
The toluene layer was washed with water and then concentrated with an evaporator and a vacuum pump to obtain 20.3 g of o-phthalaldehyde. This was a 94.7% yield based on the raw materials charged. The o-phthalaldehyde thus obtained was analyzed by gas chromatography. As a result, the purity was 99.5%.
[0020]
Example 5
Α, α, α ′, α′-Tetrachloro-o-xylene 39.0 g and water 780 g were charged into a 1 liter 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. Heated to reflux temperature (99-101 ° C.) by bath. The mixture was stirred for 8 hours in this state, and cooled to room temperature after completion of the reaction. Thereafter, the reaction solution was transferred to a 2 liter separatory funnel and extracted twice with 200 ml of chlorobenzene and once with 100 ml of chlorobenzene.
The aqueous layer was neutralized with sodium hydroxide, then transferred again to a 1 liter 4-diameter flask, added with 39.0 g of α, α, α ′, α′-tetrachloro-o-xylene and again under nitrogen flow. It heated to the recirculation | reflux temperature (100-101 degreeC) with the oil bath (repetition 1st time). The mixture was stirred for 10 hours in this state, and cooled to room temperature after completion of the reaction. Thereafter, the reaction solution was transferred to a 2 liter separating funnel and extracted three times with chlorobenzene as described above.
The aqueous layer was neutralized with sodium hydroxide, then transferred again to a 1 liter 4-diameter flask, added with 39.0 g of α, α, α ′, α′-tetrachloro-o-xylene and again under nitrogen flow. It heated to the reflux temperature (100-101 degreeC) with the oil bath (repetition 2nd time). As above, the mixture was stirred for 14 hours, and cooled to room temperature after completion of the reaction. Extraction was performed 3 times with chlorobenzene, and 3 portions of chlorobenzene were combined and washed with water.
The chlorobenzene layer was concentrated with an evaporator and a vacuum pump to obtain 61.3 g of o-phthalaldehyde. This was a 95.3% yield based on the raw materials charged. The o-phthalaldehyde thus obtained was analyzed by gas chromatography. As a result, the purity was 99.1%.
[0021]
Example 6
Α, α, α ′, α′-tetrachloro-o-xylene and 244 g of water and 2440 g of water were charged into a 3 liter four-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. Heated to reflux temperature (99-101 ° C.). The mixture was stirred for 16 hours in this state, and cooled to room temperature after completion of the reaction. Thereafter, the reaction solution was transferred to a 5 liter separatory funnel and extracted twice with 400 ml of chlorobenzene and once with 200 ml of chlorobenzene.
After recovering chlorobenzene with an evaporator, it was distilled under reduced pressure in a rectification column in which a glass tube with an inner diameter of 15 mm was filled with 15 cm of 5 mm glass helicac to obtain 112.2 g of purified o-phthalaldehyde. This was a yield of 83.7% based on the charged raw materials, and as a result of analysis by gas chromatography, the purity of o-phthalaldehyde was 99.9%.
[0022]
Example 7
Α, α, α ′, α′-tetrachloro-o-xylene (14.6 g) and calcium carbonate (6.0 g) and water (146 g) were charged into a 200 ml 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. The mixture was heated to a reflux temperature (99 to 101 ° C.) with an oil bath under a nitrogen flow. After stirring in this state for 24 hours and cooling, the reaction solution was extracted with ether and analyzed by gas chromatography. As a result, the raw material α, α, α ′, α′-tetrachloro-o-xylene disappeared completely, and the purity of o-phthalaldehyde was 99.2%.
[0023]
Comparative Example 1
Into a 500 ml 4-diameter flask equipped with a thermometer, reflux condenser, and stirrer was charged 24.4 g of α, α, α ′, α′-tetrachloro-o-xylene and 244 g of 90% sulfuric acid, and the oil was supplied under nitrogen flow. Heated to 80 ° C. by bath.
When stirred for 2 hours in this state, the reaction solution turned black, a large amount of ether insolubles was by-produced, and o-phthalaldehyde was hardly produced.
[0024]
Comparative Example 2
Α, α, α ′, α′-tetrachloro-o-xylene (14.4 g) and zinc chloride (0.7 g) were charged into a 100 ml 4-diameter flask equipped with a thermometer, reflux condenser, stirrer, and water dropping device, It heated to 120 degreeC with the oil bath under nitrogen circulation. Since the polymerization of α, α, α ′, α′-tetrachloro-o-xylene occurred with the generation of hydrogen chloride during the temperature increase, the polymerization was interrupted before dropping water.
[0025]
Comparative Example 3
Α, α, α ′, α′-tetrachloro-o-xylene (36.6 g) and water (109.8 g) were charged into a 200 ml 4-diameter flask equipped with a thermometer, a reflux condenser, and a stirrer. The mixture was heated to the reflux temperature (99 to 101 ° C.) with an oil bath. The mixture was stirred at reflux for 40 hours, and after cooling, the reaction solution was extracted with ether and analyzed by gas chromatography. As a result, 3.4% of the raw material α, α, α ′, α′-tetrachloro-o-xylene remained, 63.3% of o-phthalaldehyde, and 29.8% of phthalide were produced. The hydrochloric acid concentration at the end of the reaction was calculated to be 16.2%.
[0026]
【Effect of the invention】
According to the production method of the present invention, side reactions are suppressed because an α, α, α ′, α′-tetrahalogeno-o-xylene compound is used as a starting material and excess water is used as a reaction reagent and a reaction solvent. An aromatic-o-dialdehyde compound can be produced with high yield and high purity.
Furthermore, since organic solvents and organic acids other than raw materials are not required at all, their recovery work is unnecessary, and the method of the present invention is excellent in terms of economy and workability, and is an industrially implemented method. It is suitable as.

Claims (2)

The reaction reagent other than these is used in the presence of 4 to 20 times by weight of water of the α, α, α ′, α′-tetrahalogeno-o-xylene compound represented by the general formula (1). A process for producing an aromatic-o-dialdehyde compound, characterized in that the hydrolysis is carried out without hydrolysis.
General formula (1)

(Wherein R ₁ represents an alkyl group, a hydroxyl group, an alkoxy group, a nitro group, a cyano group, a halogen atom or a carboxyl group, n represents an integer of 0 to 4, and when n is 2 or more, R ₁ They may be the same or different, and X represents a halogen atom.)   The method for producing an aromatic-o-dialdehyde compound according to claim 1, wherein the amount of the solvent other than water is 10% or less.