JP4310429B2 - Method for producing perfluoroheterocyclic compound - Google Patents

Description

（式中、ｍは０、ｎは３〜４の整数である。Ｙは以下の基から選ばれる置換基を表す。Ｒはアルキル基、Ｒｆはペルフルオロアルキル基を表す。）
【化５】

【化６】
一般式２

（ｍは０、ｎは３〜４の整数である。）
（２） 電解フッ素化反応を液体フッ化水素中で行うことを特徴とする上記（１）に記載のペルフロオロ複素環化合物の製造方法。
【０００８】
【発明の実施の形態】
本発明の電解フッ素化反応においては、原料として、前記一般式１で示される特定なオキソラン又はオキサン誘導体を用いることが重要である。
すなわち、ペルフルオロカルボン酸フルオリドの出発原料として対応するカルボン酸クロリドを用いた場合には、環式エーテル基置換−2−カルボニルクロリドを持つ場合には, 不安定な化合物であるために、電解フッ素化の原料としては適当でない。例えば、オキソラン-2-カルボニルクロリドはそれ自体室温で不安定な化合物｛A. Mooradian, C.J. Cavallito, A.J. Bergman, E.J. Lawson and G.M. Suter, J. Amer. Chem. Soc., 71, 3372 (1949)｝であり、無水フッ化水素酸中では脱カルボニル化反応が優先しておきるために、この化合物の電解フッ素化からは、目的とするペルフルオロオキソラン−2−カルボニルフロリドはほとんど得ることができない。本発明者らは、これを解決するために試行錯誤の結果、上記一般式（１）における、置換基Ｙとして、ヒドロキシルメチル基（−CH₂OH）や、これをカルボメトキシ基などのエステルに変換したもの更にはアルコキカルボニル等を選定し、このものを電解フッ素化すれば所望のペルフルオロオキソラン−2−カルボニルフルオリドが好収率で得られることを見いだした。
【０００９】
Ｙの具体例としては、たとえば以下のような基を挙げることができる。
【化７】

【００１０】
本発明で好ましく使用される一般式１で示される化合物を示せば以下のとおりである。
【化８】

【００１１】
特に、置換基として、ヒドロキシルメチル基（-CH₂OH）をカルボメトキシ基などのエステルに変換したものは、-CH₂OH基の脱水酸基反応を抑制する機能を有し、目的物を好収率で得ることができるので好ましく使用される。
【００１２】
本発明の原料である上記一般式１で示される化合物としては、例えば以下のものを例示することができる。
【化９】

【００１３】
本発明に係る電解フッ素化反応は、液体フッ化水素中で行なわれる。
また、前記原料であるオキソラン及びオキサン誘導体の濃度は、特に制限はないが、1〜80重量％の範囲で選定するのがよいが、濃度があまり高くなるとタール状化合物が生成し易くなるので、好ましくは3〜20重量％の濃度で選ばれる。
【００１４】
電解フッ素化の反応条件に特別な制約はないが、電流密度が高すぎると電解電圧が高くなりすぎて副反応が生じやすくなるで、電流密度は、0.01〜10A/dm²、好ましくは0.1〜5A/dm²の範囲で行うのが好ましい。電解温度は、−20〜50℃、好ましくは−10〜20℃の範囲とするのが好ましい。この電解温度が低すぎると電解電圧が高くなりやすく、一方高すぎるとフッ化水素の逃散が起こりやすくなるので望ましくない。
【００１５】
また、電解反応は通常常圧で行われるが、所望に応じ加圧下で行うこともできる。加圧下で行う場合は、フッ化水素の沸点が上昇するために、反応系の冷却を緩和しうる長所がある。また、該反応は連続法又はバッチ式のいずれの方法も用いることができるが、バッチ式で行う場合、反応を完結させるための電解時間は電流密度や原料の量に左右されるが、一般に電気量が理論電気量の80〜200％になるような時間を要して反応を行うのが好ましい。
【００１６】
また、上記電解フッ素化反応の条件は、使用する原料の種類によって異なるので、目的生成物の収率及び電流効率などを考慮して適宜選択することが望ましい。また、効率よく電解フッ素化を行い、目的生成物の収率を向上させるために、反応中電解液をかき混ぜることが望ましく、その為には機械的な強制攪拌や不活性ガスの導入によるかき混ぜなどの方法を用いることができる。
また、本発明方法における電解フッ素化反応においては、従来電解フッ素化反応で常用されている電解槽をそのまま適用することができる。
【００１７】
このようにして得られたペルフルオロ環式エーテル基置換カルボニルフルオリドは、ほとんどが揮発性の化合物として、冷却トラップに捕集されるが、一部は電解槽内に残留し、液体フッ化水素と分離して二層となるために、その下層を形成している該化合物を電解終了後にドレインして取り出すことができる。
このような電解フッ素化反応により、前記一般式２で表されるペルフルオロ環式エーテル基置換カルボニルフルオリドが得られる。
本発明の目的化合物である、前記一般式２で示される化合物としては、たとえば、以下のような化合物が例示される。
【００１８】
【化１０】

【００１９】
【実施例】
以下、本発明のペルフルオロ環式エーテル基置換カルボニルフルオリドの製造方法を実施例を挙げて更に詳細に説明する。
なお、電解槽は、モネルメタル製のものを、電極にはニッケル板製の陽極７枚と陰極８枚とを極間距離２mmで交互に配列した、有効面積が7.5dm²のものを使用した。
【００２０】
実施例１
容量450mlの無水フッ化水素酸にテトラヒドロフルフリルアルコールの酢酸エステル（一般式１において、m=0, n=3, Y=−CH₂OC(O)CH₃）(20.2g)を溶解し、この溶液を、5.2〜5.8Vで100Ahr電解した。
生成ガスはフッ化ナトリウム管を通じて随伴するフッ化水素を除いた後、ドライアイスエタノール浴で−78℃に冷却したトラップで補集した。冷却トラップ中にはフルオロカーボン混合物11.5gが捕集された。また、電解終了後、電解槽下部のドレインコックを開き、フルオロカーボン混合物（セルドレイン化合物）6.4gを抜き出した。
これらのフルオロカーボン混合物を、ガスクロマトグラフィー[キャリアー：He、液相：Fomblin YR 25%、坦体：60〜80メッシュ クロモソーブPAW]、IR、¹⁹F-NMR、Mass、元素分析などにより分析したところ、目的物のペルフルオロ(オキソラン−2−カルボニルフルオロリド)が3.2g（収率9.4モル%）が得られた。
このペルフルオロ(オキソラン−2−カルボニルフルオリド)の赤外吸収スペクトルデータは以下のとおりであった。
【００２１】
IR(gas): 1888 ν(C=O) (ms), 1381 (w), 1346 (ms), 1270 (ms, sh), 1227 (s), 1181 (ms), 1161 (ms), 1109 (vs), 1080 (s, sh), 1007 (ms), 910 (ms), 698 (w), 571 (w).
【００２２】
ペルフルオロ（オキソラン−2−カルボニルフルオリド)は、更に対応するメチルエステルに誘導して、その物性を測定した。
メチルエステルとしての物性値は、沸点 103.5〜104.5℃（文献値：106℃）, 密度がd₄ ²⁰1.5654, 屈折率がn_D ²⁰ 1.3158でありその分光学的データ(IR, Mass)は次のようであった。
【００２３】
IR (capillary film): 2968 ν(CH) (w), 1792 ν(C=O) (s), 1445 (ms), 1375 (ms), 1352 (ms), 1301 (ms), 1217 (vs), 1176 (s), 1157 (s), 1126 (s), 1082 (s), 1007 (s), 962 (ms), 905 (ms), 816 (w), 777 (ms), 569 (w).
【００２４】
Mass (796-3): 197 [M-C(O)OCH₃]⁺ (1.8), 181 C₄F₇ ⁺ (2.2), 169 C₃F₇ ⁺ (8.2), 131 C₃F₅ ⁺ (5.1), 119 C₂F₅ ⁺ (7.8), 109 CF₂C(O)OCH₃ ⁺ (5.7), 100 C₂F₄ ⁺ (13.8), 81 C₂F₃ ⁺ (5.9), 69 CF₃ ⁺ (46.0), 59 C(O)OCH₃ ⁺ (100), 47 C(O)F⁺ (4.6).
【００２５】
¹⁹F NMR:
【化１１】

【００２６】
実施例 ２
原料としてテトラヒドロフルフリルアルコールとテトラヒドロフラン−2−カルボン酸とのエステル（一般式１において、m=0, n=3, Y=−CH₂OC(O)−c−C₄H₇Oのもの）(22.1g, 0.11mol)を用い、電解電圧は、5.5〜6.8Vで98Ahr電解した以外は実施例１と同様にして実験を行った。電解終了後、冷却トラップ中にはフルオロカーボン混合物18.1gが得られたが、この場合には、電解槽下部よりのセルドレイン化合物は得られなかった。目的物のペルフルオロ（オキソラン−2−カルボニルフルオリド）が5.3g得られた。仕込んだ原料を基にするとペルフルオロ（オキソラン−2−カルボニルフルオリド）の収率は19.5モル%であった。
【００２７】
実施例 ３
原料としてテトラヒドロピラン−2−メタノールとトリフルオロ酢酸のエステル（一般式１にいて、m=0, n=4, Y=−CH₂OC(O)CF₃）のもの）(27.9g, 0.131mol)を用い、電解電圧は、5.1〜5.6Vで88Ahr電解した以外は実施例１と同様にして実験を行った。電解終了後、冷却トラップ中にはフルオロカーボン混合物7.0gと電解槽下部よりセルドレイン化合物が9.6g捕集された。これらの生成物を分析したところ、目的物のペルフルオロ（オキサン−2−カルボニルフルオリド）が3.0g得られた。仕込んだ原料を基にするとペルフルオロ（オキサン−2−カルボニルフルオリド）の収率は6．9モル%であった。
ペルフルオロ(オキサン−2−カルボニルフルオリド)の赤外吸収スペクトルデータは以下のとおりであった。
【００２８】
IR (gas): 1886 ν(C=O) (s), 1355 (w), 1340 (w), 1286 (ms), 1253 (ms, sh), 1207 (s), 1140 (vs), 1055 (ms), 986 (ms), 1011 (w), 899 (ms), 802 (w), 721 (w), 644 (w), 611 (w).
【００２９】
ペルフルオロ(オキサン−2−カルボニルフルオリド)の物性値は対応するメチルエステルに誘導化して測定した。
そのメチルエステルとしての物性値は、沸点116.5〜117.5℃、密度 d₄ ²⁰1.6579、屈折率 n_D ²⁰ 1.3211でありその分光学的データは次のようである。
【００３０】
IR (capillary film): 2968 ν(CH) (w), 1788 ν(C=O) (s), 1443 (w), 1352 (ms), 1312 (ms), 1285 (ms), 1263 (s), 1227 (s), 1198 (vs), 1151 (s), 1134 (s), 1057 (ms), 988 (s), 957 (ms), 895 (w), 779 (ms), 642 (w), 613 (w), 552 (w).
【００３１】
Mass: 247 [M-C(O)OCH₃]⁺ (1.4), 231 C₅F₉ ⁺ (1.8), 219 C₄F₉ ⁺ (2.9), 181 C₄F₇ ⁺ (2.1), 169 C₃F₇ ⁺ (3.7), 140 C₂F₃C(O)OCH₃ ⁺ (2.6), 131 C₃F₅ ⁺ (17.7), 119 Ｃ₂F₅ ⁺ (6.5), 109 CF₂C(O)OCH₃ ⁺ (4.3), 100 C₂F₄ ⁺ (18.5), 81 C₂F₃ ⁺ (5.9), 69 CF₃ ⁺ (41.3), 59 C(O)OCH₃ ⁺ (100) 47 C(O)F⁺ (4.0).
【００３２】
¹⁹F NMR:
【化１２】

【００３３】
実施例 ４
原料としてテトラヒドロフルフリルアルコールとメタンスルホン酸とのエステル（一般式１において、m=0, n=4, Y=−CH₂OS(O)₂OCH₃）(21.0g, 0.116mol)を用いて、電解電圧は5.6〜7.0Vで71Ahr電解を行い、また冷却トラップに、それぞれドライアイス(−78℃)と液体窒素で冷却したトラップを用いた以外は実施例１と同様にして実験を行った。電解終了後、液体窒素で冷却したトラップ中にはフルオロカーボン混合物12.6gが得られたが、主成分はテトラフルオロメタン、スルフリルフルオリド、及びトリフルオロメタンスルホニルフルオリドであった。またドライアイスで冷却したトラップには4.7gのフルオロカーボン混合物が得られた。これを、GC, IRなどにより分析したところ、目的物のペルフルオロ（オキソラン−2−カルボニルフルオリド）が0.7g得られた。仕込んだ原料を基にするとペルフルオロ（オキソラン−2−カルボニルフルオリド）の収率は2.5モル%であった。
【００３４】
【発明の効果】
本発明の製造方法によれば、各種フッ素化合物の合成中間体として有用なペルフルオロ環式エーテル基置換-2-カルボニルフルオリドを、容易に入手しうる原料を用い、かつ簡便な電解処理工程により好収率で製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing perfluoroheterocyclic compounds useful as synthetic intermediates for fluorine-containing products such as surfactants, agricultural chemicals and pharmaceuticals, and fluorine-containing polymer monomers.
[0002]
[Prior art]
Perfluorocarboxylic acids having a perfluoroheterocycle with oxygen or nitrogen as a heteroatom can be expected to exhibit various functions by skillfully utilizing their molecular structure, and are therefore attracting attention as intermediates for the synthesis of functional fluorine compounds. Has been.
For example, in order to produce a meltable fluororesin (PFA resin) that can be injection molded, perfluorovinyl ether and tetrafluoroethylene are used for the purpose of increasing the amorphous property of polytetrafluoroethylene polymer (that is, lowering the crystallinity). Used as a comonomer. The perfluorovinyl ether is synthesized by several steps of reaction using perfluorocarboxylic acid fluoride and hexafluoropropene as raw materials.
In this case, as the perfluorovinyl ether serving as a comonomer, a larger effect can be expected with a smaller amount of the perfluoroalkoxy group of the side chain group, but a perfluoro cyclic ether group composed of a bulky 5-membered or 6-membered ring. Substituted carbonyl fluorides can be said to be excellent compounds that meet the basic requirements for the production of the indicated comonomer, perfluorovinyl ether.
[0003]
Conventionally, these perfluoroheterocyclic compounds, for example, (1) 6-membered ring perfluorooxan-2-carbonyl fluoride are obtained by subjecting adipic acid to an electrofluorination reaction to form perfluorooxo which is a 5-membered ring isomer. It is obtained as a side reaction product (cyclization reaction product) together with lan-2-acetyl fluoride (Patent Document 1) and (2) 5-membered ring perfluorooxolane-2-carbonyl fluoride is obtained by After several steps of reaction using lan-2-acetyl fluoride as a raw material, 2-difluoromethyl-heptafluorooxolane was synthesized as an intermediate. In the final reaction, 2-difluoromethyl-heptafluorooxolane was synthesized. It is synthesized by oxidizing the side chain group at the 2-position (-CF ₂ H) with a mixed gas of chlorine and nitric oxide at a high temperature (500 ° C) and converting it to a carboxyl group. (Non-Patent Document 2).
[0004]
However, in the synthesis method (1) by electrolytic fluorination reaction of dibasic carboxylic acid (adipic acid), perfluorooxane-2-carbonyl fluoride is produced as a side reaction with perfluorooxolane-2-acetyl fluoride. It is only produced as a product (cyclization reaction product), and there is a problem that the yield is extremely low. In addition, the synthesis method (2) uses a side reaction product (cyclization reaction product) as a production raw material. Perfluorooxolane-2-acetyl fluoride, which requires a multi-stage reaction and a reaction under harsh conditions in order to obtain the desired product.
[0005]
[Non-Patent Document 1]
T. Abe and S. Nagase, in "Preparation, Properties, and Industrial Applications of Organofluorine Compounds", ed. RE Banks, Ellis Horwood Limited, Chichester, 1982, P.31
[Non-Patent Document 2]
B. Zapevalova, VS Plashkin, BN Selishchev, KN Bil'dinov, MS Shcherbakova, J. Org. Chem. USSR (Engl, Transl.), Vol. 13, 2389-2391 (1977)
[0006]
[Problems to be solved by the invention]
The present invention overcomes these problems and uses perfluorocyclic ether group-substituted 2-carbonyl fluoride useful as a synthetic intermediate for various fluorine compounds in a simple process using readily available raw materials. An object of the present invention is to provide an industrially advantageous production method that can be obtained in good yield.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that when a specific cyclic ether compound is electrolytically fluorinated in liquid hydrogen fluoride or the like, the corresponding perfluorocyclic ether group-substituted carbonyl fluoride is obtained. Knowing that it can be obtained simply and with good yield, the present invention has been completed.
That is, according to the present invention, the following inventions are provided.
(1) A method for producing a perfluoroheterocyclic compound represented by the following general formula 2, wherein the compound represented by the following general formula 1 is electrolytically fluorinated.
[Formula 4]
General formula 1

(In the formula, m is 0 and n is an integer of 3 to 4. Y represents a substituent selected from the following groups . R represents an alkyl group, and Rf represents a perfluoroalkyl group.)
[Chemical formula 5]

[Chemical 6]
General formula 2

( M is 0, n is an integer of 3-4. )
(2) The method for producing a perfluoroheterocyclic compound as described in (1) above, wherein the electrolytic fluorination reaction is carried out in liquid hydrogen fluoride.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the electrolytic fluorination reaction of the present invention, it is important to use a specific oxolane or oxane derivative represented by the general formula 1 as a raw material.
In other words, when the corresponding carboxylic acid chloride is used as a starting material for perfluorocarboxylic acid fluoride, it has a cyclic ether group-substituted 2-carbonyl chloride. It is not suitable as a raw material. For example, oxolane-2-carbonyl chloride itself is a compound that is unstable at room temperature {A. Mooradian, CJ Cavallito, AJ Bergman, EJ Lawson and GM Suter, J. Amer. Chem. Soc., 71, 3372 (1949)}. Since the decarbonylation reaction is given priority in anhydrous hydrofluoric acid, the target perfluorooxolane-2-carbonyl fluoride can hardly be obtained from the electrolytic fluorination of this compound. As a result of trial and error in order to solve this problem, the present inventors have converted the hydroxyl group (—CH ₂ OH) into an ester such as a carbomethoxy group as the substituent Y in the general formula (1). It was found that the desired perfluorooxolane-2-carbonyl fluoride can be obtained in good yield by selecting the converted one and further alkoxycarbonyl and the like and subjecting this to electrolytic fluorination.
[0009]
Specific examples of Y include the following groups.
[Chemical 7]

[0010]
The compound represented by the general formula 1 preferably used in the present invention is as follows.
[Chemical 8]

[0011]
In particular, as a substituent, a hydroxylmethyl group (—CH ₂ OH) converted to an ester such as a carbomethoxy group has a function of suppressing the dehydroxylation reaction of the —CH ₂ OH group, and the target product is well received. Since it can be obtained at a rate, it is preferably used.
[0012]
As a compound shown by the said General formula 1 which is a raw material of this invention, the following can be illustrated, for example.
[Chemical 9]

[0013]
The electrolytic fluorination reaction according to the present invention is performed in liquid hydrogen fluoride.
Further, the concentration of the oxolane and oxane derivative as the raw material is not particularly limited, but it is preferable to select the concentration within the range of 1 to 80% by weight. However, if the concentration is too high, a tar-like compound is easily generated. It is preferably selected at a concentration of 3 to 20% by weight.
[0014]
There are no particular restrictions on the reaction conditions for electrolytic fluorination, but if the current density is too high, the electrolysis voltage becomes too high and side reactions are likely to occur, and the current density is 0.01 to 10 A / dm ² , preferably 0.1 to It is preferable to carry out within the range of 5 A / dm ² . The electrolysis temperature is −20 to 50 ° C., preferably −10 to 20 ° C. If the electrolysis temperature is too low, the electrolysis voltage tends to be high, while if it is too high, escape of hydrogen fluoride tends to occur, which is not desirable.
[0015]
The electrolytic reaction is usually performed at normal pressure, but can be performed under pressure as desired. When carried out under pressure, since the boiling point of hydrogen fluoride increases, there is an advantage that cooling of the reaction system can be relaxed. In addition, the reaction can be carried out by either a continuous method or a batch method, but in the case of a batch method, the electrolysis time for completing the reaction depends on the current density and the amount of raw material, but generally electric It is preferable to carry out the reaction in such a time that the amount is 80 to 200% of the theoretical electricity amount.
[0016]
The conditions for the electrolytic fluorination reaction vary depending on the types of raw materials used, and therefore it is desirable to select them appropriately in consideration of the yield of the target product and current efficiency. In addition, it is desirable to stir the electrolyte during the reaction in order to efficiently perform electrolytic fluorination and improve the yield of the target product. For this purpose, mechanical agitation or stirring by introducing an inert gas, etc. This method can be used.
Moreover, in the electrolytic fluorination reaction in the method of the present invention, an electrolytic cell conventionally used in an electrolytic fluorination reaction can be applied as it is.
[0017]
The perfluorocyclic ether group-substituted carbonyl fluoride thus obtained is mostly collected as a volatile compound in the cooling trap, but a part of it remains in the electrolytic cell, and liquid hydrogen fluoride and Since it is separated into two layers, the compound forming the lower layer can be drained and taken out after electrolysis.
By such electrolytic fluorination reaction, the perfluoro cyclic ether group-substituted carbonyl fluoride represented by the general formula 2 is obtained.
Examples of the compound represented by the general formula 2, which is the target compound of the present invention, include the following compounds.
[0018]
[Chemical Formula 10]

[0019]
【Example】
EXAMPLES Hereinafter, the manufacturing method of the perfluoro cyclic ether group substituted carbonyl fluoride of this invention is demonstrated in detail with an Example.
The electrolytic cell was made of Monel Metal, and the electrode used was an electrode having an effective area of 7.5 dm ² in which 7 nickel plate anodes and 8 cathodes were alternately arranged with a distance of 2 mm between the electrodes.
[0020]
Example 1
(In general formula 1, m = 0, n = 3, Y = -CH 2 OC (O) CH 3) tetrahydrofurfuryl alcohol acetates in anhydrous hydrofluoric acid capacity 450ml was dissolved (20.2 g), This solution was electrolyzed at 5.2 to 5.8 V for 100 Ahr.
The generated gas was collected by a trap cooled to −78 ° C. in a dry ice ethanol bath after removing the accompanying hydrogen fluoride through a sodium fluoride tube. 11.5 g of fluorocarbon mixture was collected in the cold trap. Further, after completion of electrolysis, the drain cock at the bottom of the electrolytic cell was opened, and 6.4 g of a fluorocarbon mixture (cell drain compound) was extracted.
When these fluorocarbon mixtures were analyzed by gas chromatography [carrier: He, liquid phase: Fomblin YR 25%, carrier: 60-80 mesh chromosorb PAW], IR, ¹⁹ F-NMR, Mass, elemental analysis, etc., As a result, 3.2 g (yield: 9.4 mol%) of perfluoro (oxolane-2-carbonylfluoride) as a target product was obtained.
The infrared absorption spectrum data of this perfluoro (oxolane-2-carbonyl fluoride) was as follows.
[0021]
IR (gas): 1888 ν (C = O) (ms), 1381 (w), 1346 (ms), 1270 (ms, sh), 1227 (s), 1181 (ms), 1161 (ms), 1109 ( vs), 1080 (s, sh), 1007 (ms), 910 (ms), 698 (w), 571 (w).
[0022]
Perfluoro (oxolane-2-carbonyl fluoride) was further derivatized to the corresponding methyl ester and its physical properties were measured.
The physical properties of the methyl ester are as follows: Boiling point: 103.5-104.5 ° C (Reference value: 106 ° C), Density: d ₄ ²⁰ 1.5654, Refractive index: n _D ²⁰ 1.3158 The spectroscopic data (IR, Mass) are It seemed.
[0023]
IR (capillary film): 2968 ν (CH) (w), 1792 ν (C = O) (s), 1445 (ms), 1375 (ms), 1352 (ms), 1301 (ms), 1217 (vs) , 1176 (s), 1157 (s), 1126 (s), 1082 (s), 1007 (s), 962 (ms), 905 (ms), 816 (w), 777 (ms), 569 (w) .
[0024]
Mass (796-3): 197 [MC (O) OCH ₃ ] ⁺ (1.8), 181 C ₄ F ₇ ⁺ (2.2), 169 C ₃ F ₇ ⁺ (8.2), 131 C ₃ F ₅ ⁺ (5.1) , 119 C ₂ F ₅ ⁺ (7.8), 109 CF ₂ C (O) OCH ₃ ⁺ (5.7), 100 C ₂ F ₄ ⁺ (13.8), 81 C ₂ F ₃ ⁺ (5.9), 69 CF ₃ ⁺ ( 46.0), 59 C (O) OCH ₃ ⁺ (100), 47 C (O) F ⁺ (4.6).
[0025]
¹⁹ F NMR:
Embedded image

[0026]
Example 2
Esters of tetrahydrofurfuryl alcohol and tetrahydrofuran-2-carboxylic acid as a raw material (in general formula 1, m = 0, n = 3, Y = -CH 2 OC (O) -c-C 4 H 7 O ones) (22.1 g, 0.11 mol) was used, and the experiment was performed in the same manner as in Example 1 except that the electrolysis voltage was 98 Ahr at 5.5 to 6.8 V. After completion of the electrolysis, 18.1 g of the fluorocarbon mixture was obtained in the cooling trap, but in this case, the cell drain compound from the lower part of the electrolytic cell was not obtained. 5.3 g of the desired perfluoro (oxolane-2-carbonyl fluoride) was obtained. Based on the raw materials charged, the yield of perfluoro (oxolane-2-carbonyl fluoride) was 19.5 mol%.
[0027]
Example 3
Esters of tetrahydropyran-2-methanol and trifluoroacetic acid as the starting material (Formula 1 Niite, m = 0, n = 4 , Y = -CH 2 OC (O) CF 3) ones) (27.9 g, 0.131 mol ) And the electrolysis voltage was 5.1 to 5.6 V, and the experiment was performed in the same manner as in Example 1 except that electrolysis was performed for 88 Ahr. After completion of electrolysis, 7.0 g of fluorocarbon mixture and 9.6 g of cell drain compound were collected from the bottom of the electrolytic cell in the cooling trap. When these products were analyzed, 3.0 g of the desired perfluoro (oxane-2-carbonyl fluoride) was obtained. Based on the raw materials charged, the yield of perfluoro (oxane-2-carbonyl fluoride) was 6.9 mol%.
The infrared absorption spectrum data of perfluoro (oxane-2-carbonyl fluoride) was as follows.
[0028]
IR (gas): 1886 ν (C = O) (s), 1355 (w), 1340 (w), 1286 (ms), 1253 (ms, sh), 1207 (s), 1140 (vs), 1055 ( ms), 986 (ms), 1011 (w), 899 (ms), 802 (w), 721 (w), 644 (w), 611 (w).
[0029]
The physical properties of perfluoro (oxan-2-carbonyl fluoride) were measured by derivatization to the corresponding methyl ester.
The physical properties of the methyl ester are as follows: boiling point 116.5-117.5 ° C., density d ₄ ²⁰ 1.6579, refractive index n _D ²⁰ 1.3211, and the spectroscopic data are as follows.
[0030]
IR (capillary film): 2968 ν (CH) (w), 1788 ν (C = O) (s), 1443 (w), 1352 (ms), 1312 (ms), 1285 (ms), 1263 (s) , 1227 (s), 1198 (vs), 1151 (s), 1134 (s), 1057 (ms), 988 (s), 957 (ms), 895 (w), 779 (ms), 642 (w) , 613 (w), 552 (w).
[0031]
Mass: 247 [MC (O) OCH ₃ ] ⁺ (1.4), 231 C ₅ F ₉ ⁺ (1.8), 219 C ₄ F ₉ ⁺ (2.9), 181 C ₄ F ₇ ⁺ (2.1), 169 C ₃ F ₇ ⁺ (3.7), 140 C ₂ F ₃ C (O) OCH ₃ ⁺ (2.6), 131 C ₃ F ₅ ⁺ (17.7), 119 C ₂ F ₅ ⁺ (6.5), 109 CF ₂ C (O) OCH ₃ ⁺ (4.3), 100 C ₂ F ₄ ⁺ (18.5), 81 C ₂ F ₃ ⁺ (5.9), 69 CF ₃ ⁺ (41.3), 59 C (O) OCH ₃ ⁺ (100) 47 C (O) F ⁺ (4.0).
[0032]
¹⁹ F NMR:
Embedded image

[0033]
Example 4
Using an ester of tetrahydrofurfuryl alcohol and methanesulfonic acid as a raw material (in formula 1, m = 0, n = 4, Y = —CH ₂ OS (O) ₂ OCH ₃ ) (21.0 g, 0.116 mol) The experiment was carried out in the same manner as in Example 1 except that the electrolysis voltage was 5.6 to 7.0 V and 71 Ahr electrolysis was performed, and a trap cooled with dry ice (−78 ° C.) and liquid nitrogen was used as the cooling trap. . After the electrolysis, 12.6 g of a fluorocarbon mixture was obtained in a trap cooled with liquid nitrogen, and the main components were tetrafluoromethane, sulfuryl fluoride, and trifluoromethanesulfonyl fluoride. Moreover, 4.7 g of fluorocarbon mixture was obtained in the trap cooled with dry ice. When this was analyzed by GC, IR, etc., 0.7 g of the desired product perfluoro (oxolane-2-carbonyl fluoride) was obtained. Based on the raw materials charged, the yield of perfluoro (oxolane-2-carbonyl fluoride) was 2.5 mol%.
[0034]
【The invention's effect】
According to the production method of the present invention, perfluorocyclic ether group-substituted 2-carbonyl fluoride, which is useful as an intermediate for synthesis of various fluorine compounds, is preferably obtained by using a readily available raw material and by a simple electrolytic treatment process. It can be produced in a yield.

Claims (2)

A method for producing a perfluoroheterocyclic compound represented by the following general formula 2, which comprises subjecting a compound represented by the following general formula 1 to electrolytic fluorination.
[Chemical 1]
General formula 1

(In the formula, m is 0 and n is an integer of 3 to 4. Y represents a substituent selected from the following groups . R represents an alkyl group, and Rf represents a perfluoroalkyl group.)

[Chemical 3]
General formula 2

( M is 0, n is an integer of 3-4. )   The method for producing a perfluoroheterocyclic compound according to claim 1, wherein the electrolytic fluorination reaction is performed in liquid hydrogen fluoride.