JPH0674252B2 - Process for producing pyrazine-N-oxides - Google Patents
Process for producing pyrazine-N-oxidesInfo
- Publication number
- JPH0674252B2 JPH0674252B2 JP61022531A JP2253186A JPH0674252B2 JP H0674252 B2 JPH0674252 B2 JP H0674252B2 JP 61022531 A JP61022531 A JP 61022531A JP 2253186 A JP2253186 A JP 2253186A JP H0674252 B2 JPH0674252 B2 JP H0674252B2
- Authority
- JP
- Japan
- Prior art keywords
- molybdenum
- pyrazine
- oxides
- pyrazines
- compound
- 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.)
- Expired - Lifetime
Links
Classifications
-
- 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
Landscapes
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Catalysts (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明はピラジン−Ｎ−オキサイド類の製造法に関す
る。TECHNICAL FIELD The present invention relates to a method for producing pyrazine-N-oxides.
従来の技術 ピラジン−Ｎ−オキサイド類は、ピラジン類と過酸化水
素を反応させて合成することができる。2. Description of the Related Art Pyrazine-N-oxides can be synthesized by reacting pyrazines with hydrogen peroxide.
従来のこの反応はピラジン類と過酸化水素水とを酢酸溶
媒中で加熱する方法（J.O.C.,23,1958,1603頁）が知ら
れているが、溶媒である酢酸を大量に使用しなければな
らず、ピラジン−Ｎ−オキサイド類の分離及び酢酸の回
収に複雑な工程を要する欠点があった。For this conventional reaction, a method of heating pyrazines and hydrogen peroxide in an acetic acid solvent is known (JOC, 23 , 1958, p. 1603), but a large amount of acetic acid must be used as the solvent. However, there is a drawback that complicated steps are required for the separation of pyrazine-N-oxides and the recovery of acetic acid.
又、タングステン酸ナトリウムを触媒とする方法（Che
m.Pharm.Bull.,22,1974,2097頁）もあるが、ピラジン−
Ｎ−オキサイドの収率が47％と低く実用的でなかった。Also, a method using sodium tungstate as a catalyst (Che
m.Pharm.Bull., 22 , 1974, p. 2097), but pyrazine-
The yield of N-oxide was as low as 47%, which was not practical.
一方、2,3,5,6−テトラメチルピラジンを５塩化モルブ
デン、又は、ヘキサカルボニルモリブデンの存在下ター
シャリーアミルハイドロパーオキサイドと反応させる方
法（Tetrahedron Letters,30,1971,2807頁）があるが、
工業的に得難い高価な過酸化物を用いる必要があり決し
て有利な方法ではなかった。On the other hand, there is a method of reacting 2,3,5,6-tetramethylpyrazine with morbutene pentachloride or tertiary amyl hydroperoxide in the presence of molybdenum hexacarbonyl (Tetrahedron Letters, 30 , 1971, page 2807). ,
This is not an advantageous method because it is necessary to use an expensive peroxide which is industrially difficult to obtain.
発明の目的及び構成 本発明者らはこれらの問題点を解決すべく鋭意検討を重
ねた結果、工業的に入手が容易な過酸化水素を酸化剤と
して用いた場合にモリブデン化合物が、ピラジン−Ｎ−
オキサイド類を合成する際の触媒として著しい効果があ
ることを発見し、本発明を完成するに至った。Objects and Structures of the Invention As a result of intensive studies made by the present inventors to solve these problems, when molybdenum which is industrially easily available is used as an oxidant, the molybdenum compound is pyrazine-N. −
They have found that they have a remarkable effect as a catalyst when synthesizing oxides, and completed the present invention.
本発明はピラジン類と過酸化水素とを反応させて、ピリ
ジン−Ｎ−オキサイド類を製造するに際し、モリブデン
化合物の存在下反応することを特徴とするものである。The present invention is characterized by reacting pyrazines with hydrogen peroxide to produce pyridine-N-oxides in the presence of a molybdenum compound.
本発明に於けるピラジン類は、ピラジン及びピラジン核
にアルキル基、アリール基、ハロゲン基、シアノ基のう
ち少なくとも１種以上の置換基を有するピラジン化合物
である。又、モリブデン化合物としては、二酸化モリブ
デン、三酸化モリブデン、モリブデン酸ナトリウム、モ
リブデン酸アンモリウム、モリブデン酸バリウム、４塩
化酸化モリブデン、二塩化二酸化モリブデン等のモリブ
デン酸化物、又は式MoXn（ＸはCl,Br,F,n＝２〜６）で
表わされるハロゲン化モリブデン、或はMo（CO）６の様
なモリブデン錯化合物である。The pyrazines in the present invention are pyrazines and pyrazine compounds having at least one substituent of an alkyl group, an aryl group, a halogen group and a cyano group in the pyrazine nucleus. Examples of molybdenum compounds include molybdenum dioxide, molybdenum trioxide, sodium molybdate, ammonium molybdate, barium molybdate, molybdenum tetrachloride, molybdenum dichloride, and other molybdenum oxides, or the formula MoXn (where X is Cl, Br. , F, n = 2 to 6), or a molybdenum complex compound such as molybdenum halide or Mo (CO) 6 .
なお過酸化水素の濃度は特に限定されないが、高濃度の
方が後処理工程に有利である。The concentration of hydrogen peroxide is not particularly limited, but a higher concentration is more advantageous for the post-treatment process.
本発明に於けるピラジン類と過酸化水素のモル比は、1:
0.2〜10であり好ましくは1:0.5〜３である。モリブデン
化合物の添加量は、ピラジン類に対して１〜20重量％の
割合で使用することができる。又、本発明に於ける反応
温度は、80℃〜100℃であり、好ましくは50℃〜90℃で
ある。The molar ratio of pyrazines to hydrogen peroxide in the present invention is 1:
It is 0.2 to 10, preferably 1: 0.5 to 3. The molybdenum compound may be added in an amount of 1 to 20% by weight based on the pyrazines. The reaction temperature in the present invention is 80 ° C to 100 ° C, preferably 50 ° C to 90 ° C.
本発明に於けるピラジン−Ｎ−オキサイド類はモノオキ
サイド化されたもの、ジオキサイド化されたものいずれ
をも含む。The pyrazine-N-oxides in the present invention include both monooxide and dioxide.
発明の効果 本発明を実施することにより、ピラジン類のＮ−オキサ
イド化を酢酸等の溶媒を用いることなく、安全に効率良
く行うことが出来るため、得られたＮ−オキサイド化合
物を容易に回収し得ると共に、溶媒の回収工程が不要で
ある。Effects of the Invention By carrying out the present invention, it is possible to safely and efficiently perform N-oxidation of pyrazines without using a solvent such as acetic acid, and thus the obtained N-oxide compound can be easily recovered. At the same time, no solvent recovery step is required.
したがってこれを工業的に実施するに於いて、酢酸溶媒
を用いる方法に比べ、より有利な条件で行うことが出来
る。Therefore, in carrying out this industrially, it can be carried out under more advantageous conditions than the method using an acetic acid solvent.
実施例 次に本発明をより詳しく説明するために、実施例を用い
て説明する。EXAMPLES Next, in order to describe the present invention in more detail, examples will be described.
実施例１ 撹拌機、温度計、滴下ロートの付いた300ml4つ口フラス
コに、水100g、ピラジン40g、三酸化モリブデン2gを入
れ80℃に加熱した。そこに35％過酸化水素水54gを１時
間で滴下し、滴下終了後さらに３時間撹拌し、その後水
酸化ナトリウム1gを加えて未反応の過酸化水素を分解し
た。次にこの反応液を濃縮乾固した後、ベンゼン200gで
熱抽出し、抽出液よりベンゼンを留去したところ、淡黄
色結晶39.5gを得た。得られた結晶を高速液体クロマト
グラフにより分析したところ、ピラジン−１−オキサイ
ド純度96.4％であった。（mp.113〜115.5℃）収率は79.
3％であった。Example 1 100 g of water, 40 g of pyrazine and 2 g of molybdenum trioxide were placed in a 300 ml four-necked flask equipped with a stirrer, a thermometer and a dropping funnel, and heated to 80 ° C. 54 g of 35% hydrogen peroxide solution was added dropwise thereto over 1 hour, and after the addition was completed, the mixture was stirred for 3 hours, and then 1 g of sodium hydroxide was added to decompose unreacted hydrogen peroxide. Next, the reaction solution was concentrated to dryness, and then heat-extracted with 200 g of benzene, and benzene was distilled off from the extract to obtain 39.5 g of pale yellow crystals. When the obtained crystals were analyzed by high performance liquid chromatography, the purity of pyrazine-1-oxide was 96.4%. (Mp.113 ~ 115.5 ℃) Yield 79.
It was 3%.
実施例２ 実施例１と同様の装置に、水100g、２−メチルピラジン
47g、三酸化モリブデン4gを入れ、90℃で35％過酸化水
素水120gを２時間かけて滴下し、その後４時間撹拌し
た。次に実施例１と同様の処理をして、黄色結晶42.3g
を得た。高速液体クロマトグラフ分析の結果、生成物は
２−メチルピラジン−１−オキサイド15.7％、３−メチ
ルピラジン−１−オキサイド18.6％、２−メチルピラジ
ン−1,4−ジオキサイド63.2％の組成であった。収率は
それぞれ12％、14.4％、48.5％であった。Example 2 The same apparatus as in Example 1 was charged with 100 g of water and 2-methylpyrazine.
47 g and 4 g of molybdenum trioxide were added, 120 g of 35% hydrogen peroxide solution was added dropwise at 90 ° C. over 2 hours, and then stirred for 4 hours. Then, the same treatment as in Example 1 was performed to obtain 42.3 g of yellow crystals.
Got As a result of high performance liquid chromatography analysis, the product had a composition of 2-methylpyrazine-1-oxide 15.7%, 3-methylpyrazine-1-oxide 18.6%, and 2-methylpyrazine-1,4-dioxide 63.2%. It was The yields were 12%, 14.4% and 48.5%, respectively.
実施例３ 実施例１に於いて、ピラジンに代って2,5−ジメチルピ
ラジン54gを用いて反応した結果、黄褐色結晶42.5gを得
た。高速液体クロマトグラフ分析の結果、2,5−ジメチ
ルピラジン−１−オキサイドの純度97.4％で（mp.109〜
112℃）、収率は66.8％であった。Example 3 As a result of reacting with 54 g of 2,5-dimethylpyrazine in place of pyrazine in Example 1, 42.5 g of yellowish brown crystals were obtained. As a result of high-performance liquid chromatographic analysis, the purity of 2,5-dimethylpyrazine-1-oxide was 97.4% (mp.
The yield was 66.8%.
実施例４ 実施例１に於いて、触媒にモリブデン酸ナトリウム4gを
用いて同様の反応をした結果、結晶36.0gを得た。高速
液体クロマトグラフ分析の結果、ピラジン−１−オキサ
イドの収率は67.4％であった。Example 4 The same reaction as in Example 1 was carried out using 4 g of sodium molybdate to obtain 36.0 g of crystals. As a result of high performance liquid chromatography analysis, the yield of pyrazine-1-oxide was 67.4%.
実施例５ 実施例４で、触媒に４臭化モリブデン3.2gを用い同様の
反応をした結果、結晶29.8gを得た。高速液体クロマト
グラフ分析の結果、ピラジン−１−オキサイドの収率は
54.7％であった。Example 5 The same reaction as in Example 4 was carried out using 3.2 g of molybdenum tetrabromide as a catalyst, and as a result, 29.8 g of crystals was obtained. As a result of high performance liquid chromatography analysis, the yield of pyrazine-1-oxide was
It was 54.7%.
実施例６ 実施例２で２−メチルピラジンの代りに２−シアノピラ
ジン10gを用い、三酸化モモリブデン0.3g、35％過酸化
水素水10gと反応した。反応液を高速液体クロロマトグ
ラフ分析にかけた結果、２−シアノピラジン−１−オキ
サイド、３−シアノピラジン−１−オキサイドの生成比
率は1:1.7で未反応原料ピークより計算した収率は、そ
れぞれ29.6％と50.3％であった。物質確認は、分取した
サンプルをNMRにより同定した。Example 6 In Example 2, 10 g of 2-cyanopyrazine was used instead of 2-methylpyrazine, and reacted with 0.3 g of molybdenum trioxide and 10 g of 35% hydrogen peroxide solution. As a result of subjecting the reaction solution to high performance liquid chromatograph analysis, the production ratio of 2-cyanopyrazine-1-oxide and 3-cyanopyrazine-1-oxide was 1: 1.7, and the yields calculated from the unreacted raw material peaks were 29.6%, respectively. % And 50.3%. For substance confirmation, the collected sample was identified by NMR.
実施例７ 実施例６において、２−シアノピラジンの代りに２−ク
ロルピラジン11.5gを用いて、同様に処理した結果、２
−クロルピラジン−１−オキサイド、３−クロルピラジ
ン−１−オキサイドをそれぞれ収率32％と52％で得た。Example 7 In the same manner as in Example 6, except that 11.5 g of 2-chloropyrazine was used instead of 2-cyanopyrazine, the result of the same treatment was 2
-Chlorpyrazine-1-oxide and 3-chloropyrazine-1-oxide were obtained in yields of 32% and 52%, respectively.
Claims (3)
ラジン−Ｎ−オキサイド類を製造するに際し、モリブデ
ン化合物の存在下反応することを特徴とするピラジン−
Ｎ−オキサイド類の製造法。1. When pyrazines are reacted with hydrogen peroxide to produce pyrazine-N-oxides, the reaction is carried out in the presence of a molybdenum compound.
Process for producing N-oxides.
ルキル基、アリール基、ハロゲン基、シアノ基のうち少
なくとも１種以上の置換基を有するピラジン化合物であ
る特許請求の範囲第１項記載の方法。2. The method according to claim 1, wherein the pyrazines are pyrazine and a pyrazine compound having at least one substituent of an alkyl group, an aryl group, a halogen group and a cyano group in the pyrazine nucleus.
酸化モリブデン、モリブデン酸ナトリウム、モリブデン
酸アンモニウム、モリブデン酸バリウム、４塩化酸化モ
リブデン、二塩化二酸化モリブデン、又は式MoXn（Ｘは
Cl,Br,F,n＝２〜６）で表わされるハロゲン化モリブデ
ンである特許請求の範囲第１項記載の方法。3. The molybdenum compound is molybdenum dioxide, molybdenum trioxide, sodium molybdate, ammonium molybdate, barium molybdate, molybdenum dichloride, molybdenum dichloride, or the formula MoXn (where X is
The method according to claim 1, which is a molybdenum halide represented by Cl, Br, F, n = 2 to 6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61022531A JPH0674252B2 (en) | 1986-02-04 | 1986-02-04 | Process for producing pyrazine-N-oxides |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61022531A JPH0674252B2 (en) | 1986-02-04 | 1986-02-04 | Process for producing pyrazine-N-oxides |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62181268A JPS62181268A (en) | 1987-08-08 |
| JPH0674252B2 true JPH0674252B2 (en) | 1994-09-21 |
Family
ID=12085381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61022531A Expired - Lifetime JPH0674252B2 (en) | 1986-02-04 | 1986-02-04 | Process for producing pyrazine-N-oxides |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0674252B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0722932B1 (en) * | 1995-01-23 | 1999-05-12 | Koei Chemical Co., Ltd. | Process for preparing tertiary amine-N-oxide |
-
1986
- 1986-02-04 JP JP61022531A patent/JPH0674252B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62181268A (en) | 1987-08-08 |
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