JPWO2002066452A1 - Method for producing fluorinated cyclic ether and use thereof - Google Patents

Abstract

Provided is a method for producing useful fluorinated cyclic unsaturated ethers and fluorinated saturated cyclic ethers from inexpensive raw materials. Further, the present invention provides useful applications of fluorinated cyclic unsaturated ethers and fluorinated saturated cyclic ethers, and novel compounds useful as intermediates for producing them. That is, in the present invention, the following compound (5) is thermally decomposed to obtain one or more fluorinated unsaturated cyclic ethers selected from the following compound (6a) and the following compound (6b). Further, a reduction reaction of the fluorinated unsaturated cyclic ether is performed to obtain one or more fluorinated saturated cyclic ethers selected from the following compound (7a) and the following compound (7b). Here, AF represents a perfluorotetrahydrofuranyl group, X represents a fluorine atom or -OM + (where M + represents a counter ion). AFCOX (5)

Description

２．式（５）で表される化合物が、下式（５ａ）で表される化合物である前記１に記載の製造方法。

３．式（５）で表される化合物におけるＸがフッ素原子である下式（５ｆ）で表される化合物が、下式（１）で表される化合物と下式（２）で表される化合物を反応させて下式（３）で表される化合物とし、該式（３）で表される化合物をフッ素化して下式（４）で表される化合物とし、該式（４）で表される化合物のエステル結合を分解反応させて得た化合物である前記１または２に記載の製造方法。
ただし、Ａ^Ｆは前記と同じ意味を示す。Ｒ^Ｃは１価有機基を示す。Ｒ^ＣＦはＲ^Ｃと同一の１価有機基、または、Ｒ^Ｃがフッ素化された１価有機基を示す。Ｘ^１はハロゲン原子を示す。Ａは下式（１ａ）、下式（１ｂ）、下式（１ｃ）、および下式（１ｄ）から選ばれる式で表される基、または該選ばれる式中の水素原子の１個以上がフッ素原子に置換された式で表される基を示す。
ＡＣＨ_２ＯＨ （１）
Ｒ^ＣＣＯＸ^１ （２）
ＡＣＨ_２ＯＣＯＲ^Ｃ （３）
Ａ^ＦＣＦ_２ＯＣＯＲ^ＣＦ （４）
Ａ^ＦＣＯＦ （５ｆ）

４．式（１）で表される化合物が下式（１）で表される化合物であり、式（３）で表される化合物が下式（３）で表される化合物であり、式（４）で表される化合物におけるＡ^Ｆが２−ペルフルオロテトラヒドロフラニル基あり、式（５ｆ）で表される化合物が下式（５ａ）で表される化合物である前記３に記載の製造方法。
ただし、Ｒ^Ｃは前記と同じ意味を示す。Ａ^１は下式（１ａ−１）、下式（１ｂ−１）、下式（１ｃ−１）、および下式（１ｄ−１）から選ばれる式で表される基、または該選ばれる式中の水素原子の１個以上がフッ素原子に置換された式で表される基を示す。
Ａ^１ＣＨ_２ＯＨ （１）
Ａ^１ＣＨ_２ＯＣＯＲ^Ｃ （３）

５．式（３）で表される化合物が、式（４）で表される化合物のエステル結合を分解反応させた反応生成物から式（５）で表される化合物と下式（２ａ）で表される化合物を得て、該式（２ａ）で表される化合物を式（１）で表される化合物と反応させて得た化合物である前記３または４に記載の製造方法。
ただし、Ｒ^ＣＦは前記と同じ意味を示す。
Ｒ^ＣＦＣＯＦ （２ａ）
６．フッ素化を、液相中でフッ素と反応させることにより行う前記３、４、または５に記載の製造方法。
７．下式（５）で表される化合物を熱分解して下式（６ａ）で表される化合物および下式（６ｂ）で表される化合物から選ばれる１種以上の化合物を得て、つぎに該１種以上の化合物の還元反応を行って、式（６ａ）で表される化合物が還元された下式（７ａ）で表される化合物および式（６ｂ）で表される化合物が還元された式（７ｂ）で表される化合物から選ばれる１種以上のフッ素化飽和環状エーテルを得ることを特徴とするフッ素化飽和環状エーテルの製造方法。
ただし、Ａ^ＦおよびＸは、それぞれ前記と同じ意味を示す。
Ａ^ＦＣＯＸ （５）

８．式（５）で表される化合物が下式（５ａ）で表される化合物である前記７に記載の製造方法。

９．下式で表されるいずれかの化合物。

ただし、Ｒ^Ｃ１およびＲ^ＣＦ１は、ペルフルオロアルキル基、ペルフルオロ（部分クロロアルキル）基、ペルフルオロ（エーテル性酸素原子含有アルキル）基、ペルフルオロ（部分クロロ（エーテル性酸素原子含有アルキル））基、またはペルフルオロテトラヒドロフラニル基を示す。
１０．下式（６ａ）で表される化合物および下式（６ｂ）で表される化合物から選ばれる１種以上のフッ素化不飽和環状エーテル、または、下式（７ａ）で表される化合物および下式（７ｂ）で表される化合物から選ばれる１種以上のフッ素化飽和環状エーテルを含む機能剤。

１１．下式（７ａ）で表される化合物を含む機能剤。

１２．水切り乾燥溶剤、ドライエッチング剤、または洗浄剤である前記１０または１１に記載の機能剤。
＜発明を実施するための最良の形態＞
本明細書の以下の説明においては、式（５）で表される化合物を化合物（５）のように記す。他の式で表される化合物においても同様に記す。
本発明においては、下記化合物（５）を熱分解して下記化合物（６ａ）および下記化合物（６ｂ）から選ばれる１種以上のフッ素化不飽和環状エーテルを得る。
Ａ^ＦＣＯＸ （５）

式（５）中のＡ^Ｆはペルフルオロテトラヒドロフラニル基を示す。化合物（５）中の−ＣＯＸ基は、ペルフルオロテトラヒドロフラニル基（Ａ^Ｆ）の２位に結合していても３位に結合していてもよく、２位に結合しているのが好ましい。すなわち、Ａ^Ｆとしては２−ペルフルオロテトラヒドロフラニル基が好ましく、化合物（５）としては、下記化合物（５ａ）が好ましい。

Ｘはフッ素原子または−Ｏ⁻Ｍ^＋を示す。Ｍ^＋はカルボン酸と塩を形成しうる陽イオンから選択され、アルカリ金属カチオンが好ましく、Ｋ^＋、Ｎａ^＋が特に好ましい。化合物（５）におけるＸが−Ｏ⁻Ｍ^＋である化合物の製造方法としては、化合物（５）のＸがフッ素原子である化合物（５ｆ）の−ＣＯＦ基を、−ＣＯＯＨに変換した後に塩を形成させる方法、または該化合物（５ｆ）に２倍モル以上のＭＯＨ（Ｍは、陽イオンが前記Ｍ^＋であるものであり、アルカリ金属原子が好ましい。）を反応させた後に、減圧下に加熱乾燥させる方法によるのが好ましい。
熱分解反応の基質である化合物（５）のうち、Ｘがフッ素原子である下記化合物（５ｆ）は、化合物（１）と化合物（２）を反応させて化合物（３）とし、該化合物（３）をフッ素化して化合物（４）とし、該化合物（４）のエステル結合を分解反応させて得た化合物であることが好ましい。ただし、Ａ^Ｆは前記と同じ意味を示す。Ｒ^Ｃは１価有機基を示す。Ｒ^ＣＦはＲ^Ｃと同一の１価有機基、または、Ｒ^Ｃがフッ素化された１価有機基を示す。Ｘ^１はハロゲン原子を示す。Ａは下式（１ａ）、下式（１ｂ）、下式（１ｃ）、および下式（１ｄ）から選ばれる式で表される基、または該選ばれる式中の水素原子の１個以上がフッ素原子に置換された式で表される基を示す。
ＡＣＨ_２ＯＨ （１）
Ｒ^ＣＣＯＸ^１ （２）
ＡＣＨ_２ＯＣＯＲ^Ｃ （３）
Ａ^ＦＣＦ_２ＯＣＯＲ^ＣＦ （４）
Ａ^ＦＣＯＦ （５ｆ）

また、化合物（５）のＸが−Ｏ⁻Ｍ^＋である化合物は、該化合物（５ｆ）から前記の方法で製造できる。
化合物（１）と化合物（２）とのエステル化反応、化合物（３）のフッ素化反応、および化合物（４）のエステル結合分解反応は、本発明者らによるＷＯ００／５６６９４に記載される各反応の方法と同様の手法および条件で実施できる。該方法によれば、化合物（５）を、安価な化合物（１）および化合物（２）から極めて効率的かつ工業的に製造できる。
上記の式（１ａ）〜式（１ｄ）において、環から伸びる線は結合手であり（結合手が結合する５員環の炭素原子の位置は限定されない。）、かつ、これらの基が１価の基であることを示す。すなわち、化合物（１）は、−ＣＨ_２ＯＨ基が式（１ａ）〜式（１ｃ）で表される基の２位または３位に結合した化合物、または、−ＣＨ_２ＯＨ基が式（１ｄ）で表されるの基の２位〜５位のいずれかに結合した化合物を示す。
Ａは、２位に−ＣＨ_２ＯＨとの結合手を有する基、すなわち、下式（１ａ−１）、下式（１ａ−２）、下式（１ａ−３）、および下式（１ａ−４）から選ばれる式で表される基、または、該選ばれる式中の水素原子の１個以上がフッ素原子に置換された式で表される基（Ａ^１）が好ましい。

Ａはフッ素原子を有しない基、すなわち、式（１ａ）、式（１ｂ）、式（１ｃ）、および式（１ｄ）から選ばれる式で表される基が好ましく、特に、式（１ａ）で表される基または式（１ｂ）で表される基が好ましく、とりわけ式（１ａ−１）で表される基または式（１ａ−２）で表される基が好ましい。
化合物（１）の具体例としては、下記化合物が挙げられる。

化合物（１）と反応させる化合物（２）において、Ｒ^Ｃは１価有機基を示す。Ｒ^Ｃとしては、フッ素化反応時に用いる液相への溶解性の観点から、その炭素数が１〜２０である基が好ましく、特に炭素数が１〜１０である基が好ましい。さらにＲ^Ｃとしてはフッ素原子を含む基（すなわち、フルオロ１価有機基）であるのが好ましく、フルオロアルキル基、フルオロ（部分クロロアルキル）基、フルオロ（エーテル性酸素原子含有アルキル）基、フルオロ（部分クロロ（エーテル性酸素原子含有アルキル））基、または後述するＡ^Ｆが好ましい。さらに、Ｒ^Ｃはペルフルオロ１価有機基であるのが好ましく、ペルフルオロアルキル基、ペルフルオロ（部分クロロアルキル）基、ペルフルオロ（エーテル性酸素原子含有アルキル）基、ペルフルオロ（部分クロロ（エーテル性酸素原子含有アルキル））基、または後述するＡ^Ｆが特に好ましい。ただし、部分クロロ化された基とは、水素原子が残る程度に塩素置換された基をいう。
化合物（２）の具体例としては、下記化合物が挙げられる。ただし、Ａ^Ｆは、ペルフルオロテトラヒロドフラニル基を示し、ペルフルオロ（２−テトラヒドロフラニル）基が好ましい。
ＣＦ_３ＣＦ_２ＣＯＦ、
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＦ、
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＦ、
Ａ^ＦＣＯＦ
化合物（２）は、市販品を用いてもよいが、後述する化合物（４）のエステル結合の分解反応において化合物（５）とともに生成しうる化合物である化合物（２ａ）（Ｒ^ＣＦＣＯＦ（２ａ））を用いてもよい。化合物（２）として化合物（２ａ）を用いる方法は、連続的な製造方法となりうるため、特に好ましい。すなわち、化合物（２）中のＲ^ＣはＲ^ＣＦと同一の基であるのが好ましく、特にＲ^Ｃがペルフルオロ１価有機基であるのが好ましい。該ペルフルオロ１価有機基の好ましい態様は前記のとおりである。
また、化合物（２）におけるＲ^ＣがＡ^Ｆである場合、すなわち化合物（２）として化合物（５）を用いた場合には、化合物（４）のエステル結合の分解反応による生成物が化合物（５）のみになって、生成物を分離する工程が不要となる利点があり好ましい。
化合物（１）と化合物（２）とのエステル化反応は、溶媒の存在下に実施してもよいが、溶媒の不存在下に実施するのが容積効率の点から好ましい。また、化合物（１）と化合物（２）との反応では、ＨＦが発生するため、ＨＦの捕捉剤としてアルカリ金属フッ化物（ＮａＦ、ＫＦ等が好ましい）やトリアルキルアミン等を反応系中に存在させてもよく、ＨＦの捕捉剤を存在させるのが好ましい。また、ＨＦの捕捉剤を使用しない場合には、ＨＦを窒素気流に同伴させて反応系外に排出するのが好ましい。アルカリ金属フッ化物を用いる場合の量は、化合物（２）に対して１〜１０倍モルを使用するのが好ましい。
化合物（１）と化合物（２）との反応温度は、−５０℃〜＋１００℃が好ましい。また、該反応の反応時間は原料の供給速度と反応に用いる化合物量に応じて適宜変更されうる。反応圧力（ゲージ圧、以下同様。）は０〜２ＭＰａが好ましい。
化合物（１）と化合物（２）の量比は、化合物（１）に対する化合物（２）の量を０．５〜５倍モルとするのが好ましく、特に１〜２倍モルとするのが好ましい。
化合物（１）と化合物（２）との反応で生成した化合物（３）を含む粗生成物は、目的に応じて精製を行っても、そのまま、つぎの反応等に用いてもよく、次の工程におけるフッ素化反応を安定に行う観点から、該粗生成物中の化合物（３）を分離精製するのが望ましい。
該粗生成物の精製方法としては、粗生成物をそのまま蒸留する方法、粗生成物を希アルカリ水などで処理して分液する方法、粗生成物を適当な有機溶媒で抽出した後に蒸留する方法、シリカゲルカラムクロマトグラフィ等が挙げられる。
化合物（３）の具体例としては、下記化合物が挙げられる。ただし、Ａ^１およびＡ^Ｆは前記と同じ意味を示す。
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＯＣＨ_２Ａ^１、
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＯＣＨ_２Ａ^１、
Ａ^ＦＣＯＯＣＨ_２Ａ^１
本発明においては、化合物（３）をフッ素化する。フッ素化反応の方法としては、ＣｏＦ_３を用いて行う方法、ＥＣＦ法、またはフッ素ガスを用いる方法が挙げられ、液相中にフッ素ガスを導入することにより行う液相フッ素化法によるのが好ましい。フッ素化反応では、化合物（３）の分子中にフッ素原子が１原子以上結合する。以下、フッ素化反応を液相フッ素化反応によって実施する態様を例に挙げて説明する。
液相フッ素化反応におけるフッ素ガスは、そのままを用いても、窒素ガス等の不活性ガスで希釈されたフッ素ガスを用いてもよい。希釈されたフッ素ガスを用いる場合のフッ素ガス濃度は、１０ｖｏｌ％以上とするのが好ましく、２０ｖｏｌ％以上とするのが特に好ましい。
液相としてはフッ素（Ｆ_２）を溶解し得る溶媒から形成されるのが好ましい。また溶媒は、化合物（３）の溶解性が高い溶媒を用いるのが好ましく、特に化合物（３）を１質量％以上溶解しうる溶媒、特には５質量％以上溶解しうる溶媒を用いるのが好ましい。溶媒量は、化合物（３）に対して、５倍質量以上が好ましく、特に１０〜１００倍質量が好ましい。
液相フッ素化に用いうる溶媒の例としては、ペルフルオロアルカン類、ペルフルオロエーテル類、ペルフルオロポリエーテル類、クロロフルオロカーボン類、クロロフルオロポリエーテル類、ペルフルオロアルキルアミン、不活性流体等が挙げられるが、後述する化合物（４）、化合物（５）または化合物（２ａ）を用いると、反応後の後処理が容易になる利点があることから特に好ましい。
化合物（３）のフッ素含有量（フッ素含有量とは、分子量に対するフッ素原子の質量の割合）は１０質量％以上であるのが好ましく、特に１０〜８６質量％であるのが好ましい。フッ素含有量が少なすぎると液相中への溶解性が極端に低くなり、フッ素化反応の反応系が不均一になる、連続反応で実施するときに化合物（３）をうまく反応系中にフィードすることができない等の問題がある。また、フッ素含有量の上限は限定されないが、あまりに高すぎるものは、化合物（３）の入手が困難であり、価格が高く、経済的ではない問題がある。
さらに、化合物（３）の分子量は２００〜１０００であるのが、気相中での好ましくないフッ素化反応を防止し、液相フッ素化反応を円滑に行いうる点で好ましい。分子量が小さすぎると化合物（３）が気化しやすくなるため、液相でのフッ素化反応時に気相中で分解反応が起こるおそれがある。一方、分子量が大きすぎると化合物（３）の精製が困難になるおそれがある。
フッ素化反応の反応形式は、バッチ方式であっても連続方式であってもよい。特に、反応収率と選択率の点から、連続方式が好ましい。またフッ素ガスは、バッチ方式で実施する場合においても、連続方式で実施する場合においても、窒素ガス等の不活性ガスで希釈したものを使用してもよい。
フッ素化反応においては、化合物（３）中の水素原子に対して、フッ素の量が常に過剰当量となるようにフッ素ガスを仕込むのが好ましく、特に１．５倍当量以上（すなわち、１．５倍モル以上）となるようにフッ素ガスを使用するのが選択率の点から好ましい。フッ素ガスは、反応の開始時点から終了時点まで常に過剰当量を保つのが好ましい。そのためには、フッ素を溶解させた液相に、化合物（３）を導入するのが好ましい。
液相フッ素化反応の反応温度は、通常は−６０℃以上かつ化合物（３）の沸点以下が好ましく、反応収率、選択率、および工業的実施のしやすさの点から−５０℃〜＋１００℃が特に好ましく、−２０℃〜＋５０℃がとりわけ好ましい。フッ素化反応の反応圧力は、０〜２ＭＰａが、反応収率、選択率、工業的な実施のしやすさの観点から特に好ましい。
さらに、液相フッ素化反応においてはフッ素化を効率的に進行させるために、反応系中にＣ−Ｈ結合含有化合物を添加する、または、紫外線照射を行う、のが好ましい。
Ｃ−Ｈ結合含有化合物としては、芳香族炭化水素が好ましく、とりわけベンゼン、トルエン等が好ましい。該Ｃ−Ｈ結合含有化合物の添加量は、化合物（３）中の水素原子に対して０．１〜１０モル％であるのが好ましく、特に０．１〜５モル％であるのが好ましい。Ｃ−Ｈ結合含有化合物は、反応系中にフッ素ガスが存在する状態で添加するのが好ましい。さらに、Ｃ−Ｈ結合含有化合物を加えた場合には、反応系を加圧するのが好ましい。加圧時の圧力としては、０．０１〜５ＭＰａが好ましい。
フッ素化反応においては、ＨＦが副生するため、副生したＨＦを除去する目的で反応系中にＨＦの捕捉剤を共存させる、または反応器ガス出口でＨＦ捕捉剤と出口ガスを接触させるのが好ましい。該ＨＦ捕捉剤としては、前述のものと同様の例が挙げられ、ＮａＦが好ましい。
反応系中にＨＦ捕捉剤を共存させる場合の量は、化合物（３）中に存在する全水素原子量に対して１〜２０倍モルが好ましく、１〜５倍モルが好ましい。
フッ素化反応で得た化合物（４）を含む粗生成物は、そのまま次の工程に用いてもよく、精製して高純度のものにしてもよい。精製方法としては、粗生成物をそのまま常圧または減圧下に蒸留する方法等が挙げられる。
化合物（４）は、化合物（３）がフッ素化された化合物であり、化合物（３）がペルフルオロ化された化合物であるのが好ましい。
フッ素反応ではＣ−ＨがＣ−Ｆに変換される反応や不飽和結合にフッ素が付加する反応がおこる。生成する化合物（４）中のＡ^ＦはＡに対応する基であり、Ｒ^ＣＦはＲ^Ｃに対応する基であり、これらの基においてはフッ素化反応の前後で炭素原子の並び方に変更はなく、化合物（３）に対応する化合物が得られる。ただし、化合物（３）中に炭素−炭素不飽和結合がある場合には、不飽和結合の１個以上にフッ素原子が付加して結合状態が変化していてもよい。Ｒ^ＣＦとしては、前記Ｒ^Ｃと同様の基が好ましく、ペルフルオロ１価有機基が特に好ましく、ペルフルオロアルキル基、ペルフルオロ（部分クロロアルキル）基、ペルフルオロ（エーテル性酸素原子含有アルキル）基、ペルフルオロ（部分クロロ（エーテル性酸素原子含有アルキル））基、またはペルフルオロテトラヒドロフラニル基、がとりわけ好ましい。化合物（４）の具体例としては、下記化合物が挙げられる。ただし、Ａ^Ｆは前記と同じ意味を示す。
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＯＣＦ_２Ａ^Ｆ、
ＣＦ_３ＣＦ_２ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＦ_２ＯＣＦ（ＣＦ_３）ＣＯＯＣＦ_２Ａ^Ｆ、
Ａ^ＦＣＯＯＣＦ_２Ａ^Ｆ。
化合物（４）は、エステル結合の分解反応によって、Ｘがフッ素原子である化合物（５）に変換される。エステル結合の分解反応は、加熱する方法、または、求核剤の存在下もしくは求電子剤と反応させることにより実施できる。加熱する方法でエステル結合の分解反応を行う場合には、化合物（４）の沸点と安定性により反応の形式を選択できる。
化合物（４）が気化しやすい化合物である場合には、気相で連続的に分解させて、得られた化合物（５）を含む出口ガスを凝縮、回収する気相法で実施するのが好ましい。気相法の反応温度は５０〜３５０℃が好ましく、５０〜３００℃が特に好ましく、とりわけ１５０〜２５０℃が好ましい。また、気相法においては、直接は関与しない不活性ガスを反応系中に共存させてもよい。不活性ガスとしては、窒素ガス、二酸化炭素ガス等が挙げられる。不活性ガスの量は化合物（４）に対して０．０１〜５０％程度が好ましい。不活性ガスの量が多いと、生成物の回収量が低減することがある。
エステル結合の分解反応を気相法で行う場合には、管型反応器を用いるのが好ましい。管型反応器を用いる場合は、滞留時間を空塔基準で０．１秒〜１０分程度にするのが好ましい。管型反応器を用いた気相反応においては、反応を促進させる目的で、反応管中にガラス、アルカリ金属の塩、またはアルカリ土類金属の塩を充填するのが好ましい。反応圧力は特に限定されないが、化合物（４）が高沸点化合物の場合には、減圧下で反応を行うのが好ましい。一方化合物（４）が低沸点化合物である場合には、生成物の分解が抑制され、かつ反応率が高くなることから、加圧下で反応を実施するのが好ましい。
一方、化合物（４）が気化しにくい化合物である場合には、反応器内で液のまま加熱する液相法を採用するのが好ましい。該方法の反応圧力は限定されない。フッ素化環状エーテル（５）を含む生成物は、加熱終了後に反応器中から一括して抜き出してもよいが、フッ素化環状エーテル（５）は化合物（４）よりも低沸点になることから、気化させて連続的に抜き出す方法によるのが好ましい。液相法の反応温度は５０〜３００℃が好ましく、特に１００〜２５０℃が好ましい。また、液相法は、溶媒を存在させてもさせなくてもよく、溶媒を存在させないのが容積効率や副生物抑制の観点から好ましい。
エステル結合の分解反応を液相中で求核剤または求電子剤と反応させる方法で行う場合には、該反応には溶媒を存在させても存在させなくてもよく、溶媒を存在させないのが、容積効率や副生物抑制の観点から好ましい。求核剤としてはフッ素アニオン（Ｆ⁻）が好ましく、特にアルカリ金属フッ化物由来のフッ素アニオンが好ましい。アルカリ金属フッ化物としては、ＮａＦ、ＫＦ、ＣｓＦが好ましく、経済性の面からＮａＦが特に好ましい。求核剤は触媒量を用いても、過剰を用いてもよい。求核剤の量は化合物（４）に対して１〜５００モル％が好ましく、１０〜１００モル％が特に好ましく、とりわけ５〜５０モル％が好ましい。反応温度の下限は−３０℃が好ましく、上限は溶媒の沸点または化合物（４）の沸点が好ましい。通常の反応温度は−２０℃〜２５０℃が特に好ましい。この方法においても、生成する化合物（５）を連続的に取り出しながら反応を実施するのが好ましい。
エステル分解反応の反応生成物中には、化合物（５）とともに化合物（２ａ）が含まれる。化合物（２ａ）が化合物（５）とが異なる化合物である場合には、化合物（２ａ）は化合物（５）から分離して、他の用途に用いることができる。化合物（２ａ）は、他の有用な化合物に変換しうる有用な中間体である。
また、化合物（２ａ）を、化合物（１）とエステル化反応させる化合物（２）に用いてエステル化反応を行ったときには、化合物（３）が製造でき、該化合物（３）からは前述の方法により化合物（５）が製造できる。たとえば、化合物（２ａ）は化合物（２）におけるＲ^ＣがＲ^ＣＦであり、Ｘがフッ素原子である化合物である。この化合物（２ａ）を化合物（２）として再利用することにより、化合物（５）を製造できる。
本発明においては、化合物（５）を熱分解する。熱分解の反応条件は特に制限されない。たとえば、熱分解反応は、気相での熱分解反応により実施するのが好ましい。
化合物（５）のＸがフッ素原子である場合には、気相熱分解反応の反応温度は、２５０〜４００℃が好ましく、２８０〜３５０℃がより好ましい。また、Ｘが−Ｏ⁻Ｍ^＋である場合には、気相熱分解反応における反応温度は、１５０〜３００℃が好ましく、２００〜２８０℃がより好ましい。気相熱分解反応における反応温度が低すぎると、変換率が低くなる傾向がある。一方、気相熱分解反応における反応温度が高すぎると、目的とする化合物以外の生成量が増加する傾向がある。
化合物（５）の熱分解反応では、脱ＣＯＦＸ反応が起こり、フラン環中に二重結合が形成し、化合物（６ａ）または化合物（６ｂ）が生成する。さらにこれらの化合物において、さらに二重結合の転移反応が起こり化合物（６ａ）からは化合物（６ｂ）が、化合物（６ｂ）からは化合物（６ａ）が生成しうる。たとえば、２位に−ＣＯＦが結合する化合物（５）の熱分解反応においては、化合物（６ａ）が生成し、また３位に−ＣＯＦが結合する化合物（５）の熱分解反応では、化合物（６ｂ）が生成する。さらに生成物の一部において二重結合の転移反応が起こると、生成物は化合物（６ａ）と化合物（６ｂ）の２種になりうる。また、熱分解反応では、通常は２種の化合物が生成する。特にＸが−Ｏ⁻Ｋ^＋で表される化合物（５）からは化合物（６ｂ）が、Ｘが−Ｏ⁻Ｎａ^＋で表される化合物（５）からは化合物（６ａ）が、優先的に生成する傾向がある。
熱分解反応の生成物の組成は、反応条件等により変化しうる。生成物が化合物（６ａ）と化合物（６ｂ）の両方である場合の、組成は特に限定されない。
化合物（６ａ）と化合物（６ｂ）は、そのまま、目的とする用途に用いてもよいが、通常の場合には、他の化合物に変換して用いる。また、２種の化合物が生成した場合には、化合物（６ａ）と化合物（６ｂ）とを分離精製した後に他の化合物に変換してもよいが、化合物（６ａ）と化合物（６ｂ）とは沸点が近く、分離に手間がかかることから、これらを分離せずに他の化合物に変換するのが好ましい。
さらに本発明においては、化合物（６ａ）および化合物（６ｂ）から選ばれる１種以上の化合物に還元反応を行うことによって、化合物（６ａ）が還元された下記化合物（７ａ）、および化合物（６ｂ）が還元された化合物（７ｂ）から選ばれる１種以上のフッ素化飽和環状エーテルを得ることができる。

還元反応では、化合物（６ａ）や化合物（６ｂ）の炭素−炭素不飽和二重結合に水素原子が付加する。この還元反応は、水素を用いて行うのが好ましく、触媒の存在下に水素を用いて行うのが特に好ましい。触媒としては、金属担持触媒が好ましい。金属担持触媒は、金属を担体に対して０．５〜５重量％、好ましくは１〜３重量％担持させた触媒であるのが好ましい。さらに金属担持触媒としては、活性炭に金属を担持させた触媒であるのが好ましく、パラジウムを担持した活性炭触媒、主成分であるパラジウムとパラジウム以外の８属元素を担持した活性炭触媒、またはＡｕを担持した活性炭触媒であるのが特に好ましい。
ここで、パラジウム以外の８属元素としては、Ｆｅ、Ｃｏ、Ｎｉ、Ｒｕ、Ｒｈ、Ｉｒ、およびＰｔから選ばれる１種以上が好ましい。パラジウム以外の８属元素の量は、パラジウムに対して０．０１〜５０質量％が好ましい。担体が活性炭である場合には、鉱物質を原料とする活性炭よりも植物質を原料とする活性炭が好ましく、特にヤシガラ活性炭が好ましい。担体の形状は、長さ約２〜５ｍｍ程度の成形炭、約４〜５０メッシュ程度の破砕炭、粒状炭等の形状を採用でき、４〜２０メッシュ程度の破砕炭、または長さ約２〜５ｍｍ程度の成形炭が好ましい。
活性炭に金属を担持させた触媒は、金属成分を担体に担持させた後、乾燥し、さらに水素で還元して活性化する方法により調製するのが好ましい。該方法で調製された触媒は、耐久性が高く、長時間使用しても活性化を必要としない利点がある。活性化させる場合には、１００〜３００℃（特には２００〜３００℃）で水素還元する方法によるのが好ましい。
水素の量は、還元反応の基質の総量から化学量論量に対して、２倍モル以上であるのが好ましく、さらに３〜８倍モルであるのが、高い収率で目的化合物が得られることから好ましい。
還元反応の温度は、常圧において１３０〜２５０℃が好ましく、特に１５０〜２００℃が好ましい。反応圧力は特に限定されない。還元反応の反応時間は、触媒に対する接触時間で４〜６０秒が好ましく、特に８〜４０秒が好ましい。さらに、還元反応は、過剰の温度上昇を制御するために、窒素などの不活性ガスで水素を希釈しながら実施してもよい。
該還元反応において、化合物（６ａ）を還元した場合には化合物（７ａ）が、化合物（６ｂ）を還元した場合には化合物（７ｂ）が、化合物（６ａ）と化合物（６ｂ）を還元した場合には化合物（７ａ）と化合物（７ｂ）からなる生成物が生成する。還元反応の生成物の組成は、還元反応の基質の組成により変化する。
還元反応の生成物が化合物（７ａ）と化合物（７ｂ）からなる場合には、これらをそのまま目的とする用途に用いてもよく、または分離してもよい。化合物（７ａ）と化合物（７ｂ）とは沸点が異なることから、これらを分離する場合には、蒸留法により分離するのが好ましい。また、熱分解反応の生成物が化合物（６ａ）と化合物（６ｂ）である場合に、還元反応で得たい化合物が化合物（７ａ）である場合には、還元反応後に蒸留分離をして化合物（７ａ）を得るのが好ましい。
本発明の製造方法により得られる、化合物（６ａ）、化合物（６ｂ）、化合物（７ａ）、および化合物（７ｂ）は、クロロフルオロカーボン類の代替化合物として優れた特性を持ち、オゾン破壊係数がゼロであり、地球温暖化係数もきわめて小さい化合物である。これらの化合物またはこれらの化合物の１種以上からなる混合物は、機能剤として有用な化合物である。
機能剤としては、冷媒、洗浄剤、水切り乾燥溶剤、溶剤、重合溶剤、ドライエッチング剤、樹脂の発泡剤等が挙げられる。このうち、化合物（６ａ）および化合物（６ｂ）から選ばれる１種または２種のフッ素化不飽和環状エーテルを含む機能剤は、水切り乾燥溶剤、ドライエッチング剤、または洗浄剤として用いるのが好ましい。また、化合物（７ａ）および化合物（７ｂ）から選ばれる１種または２種のフッ素化飽和環状エーテルを含む機能剤、特に化合物（７ａ）を含む機能剤は、ドライエッチング剤として用いるのが好ましい。
本発明のフッ素化環状エーテルの構造中には酸素原子が存在することから、これをドライエッチング剤として用いた場合には、ドライエッチング中の酸素添加操作を省略できる利点がある。
さらに、本発明によれば、該機能剤の中間体として有用な下記化合物が提供されうる。

ただし、Ｒ^Ｃ１およびＲ^ＣＦ１は、それぞれ、ペルフルオロアルキル基、ペルフルオロ（部分クロロアルキル）基、ペルフルオロ（エーテル性酸素原子含有アルキル）基、ペルフルオロ（部分クロロ（エーテル性酸素原子含有アルキル））基、またはペルフルオロテトラヒドロフラニル基、を示す。Ｒ^Ｃ１およびＲ^ＣＦ１としては、炭素数１〜２０の基が好ましく、特に、炭素数１〜１０の基が好ましい。さらにＲ^Ｃ１およびＲ^ＣＦ１としては、ペルフルオロアルキル基、ペルフルオロ（エーテル性酸素原子含有アルキル基）、が好ましい。
実施例
以下に本発明を実施例を挙げて具体的に説明するが、これらによって本発明は限定されない。なお、以下においてガスクロマトグラフィをＧＣと、ガスクロマトグラフィ質量分析をＧＣ−ＭＳと記す。また、ＧＣのピーク面積比より求まる純度をＧＣ純度、収率をＧＣ収率と記す。ＮＭＲスペクトルのピーク面積比より求まる収率をＮＭＲ収率と記す。また、テトラメチルシランをＴＭＳ、ＣＣｌ_２ＦＣＣｌＦ_２をＲ−１１３と記す。また、ＮＭＲスペクトルデータは、みかけの化学シフト範囲として示した。
［例１］エステル化工程による化合物（３ｂ−１）の製造例

２−テトラヒドロフルフリルアルコール（２０ｇ）とトリエチルアミン（２１．８ｇ）をフラスコに入れ、氷浴下撹拌した。ＦＣＯＣＦ（ＣＦ_３）ＯＣＦ_２ＣＦ_２ＣＦ_３（７１．５ｇ）を内温を１０℃以下に保ちながら１時間かけて滴下した。滴下終了後、室温で２時間撹拌し、水（５０ｍＬ）を内温１５℃以下で加えた。
得られた粗液を分液し、下層を水（５０ｍＬ）で２回洗浄し、硫酸マグネシウムで乾燥した後、ろ過し、粗液を得た。減圧蒸留で目的のエステル化合物（６６．３ｇ）を８８〜８９℃／２．７ｋＰａ（絶対圧）の留分として得た。ＧＣ純度は９８％であった。ＮＭＲ分析により化合物（３ｂ−１）の生成を確認した。
^１Ｈ−ＮＭＲ（３００．４ＭＨｚ，ＣＤＣｌ_３，ＴＭＳ）δ（ｐｐｍ）：１．６０〜１．７３（ｍ，１Ｈ），１．８６〜２．１０（ｍ，３Ｈ），３．７６〜３．９１（ｍ，２Ｈ），４．１４〜４．２２（ｍ，１Ｈ），４．２８〜４．４７（ｍ，２Ｈ）。
^１９Ｆ−ＮＭＲ（２８２．７ＭＨｚ，ＣＤＣｌ_３，ＣＦＣｌ_３）δ（ｐｐｍ）：−７９．９（１Ｆ），−８１．３（３Ｆ），−８２．１（３Ｆ），−８６．４（１Ｆ），−１２９．５（２Ｆ），−１３１．５（１Ｆ）。
［例２］フッ素化工程による化合物（４ｂ−１）の製造例

５００ｍＬのニッケル製オートクレーブに、Ｒ−１１３（３１３ｇ）を加えて撹拌し、２５℃に保った。オートクレーブガス出口には、２０℃に保持した冷却器、ＮａＦペレット充填層、および１０℃に保持した冷却器を直列に設置した。なお、−１０℃に保持した冷却器からは凝集した液をオートクレーブに戻すための液体返送ラインを設置した。窒素ガスを１．０時間吹き込んだ後、窒素ガスで２０％に希釈したフッ素ガスを、流速８．０８Ｌ／ｈで１時間吹き込んだ。つぎに、フッ素ガスを同じ流速で吹き込みながら、例１で得た化合物（３ｂ−１）（５．０１ｇ）をＲ−１１３（１００ｇ）に溶解した溶液を４．７時間かけて注入した。
つぎに、フッ素ガスを同じ流速で吹き込みながら、ベンゼン濃度が０．０１ｇ／ｍＬのＲ−１１３溶液（９ｍＬ）を２５℃から４０℃にまで昇温しながら注入し、オートクレーブのベンゼン注入口を閉め、さらにオートクレーブの出口バルブを閉め、０．２０ＭＰａになったところでオートクレーブのフッ素ガス入り口バルブを閉めて、０．４時間撹拌を続けた。つぎに圧力を常圧にし、反応器内温度を４０℃に保ちながら、上記のベンゼン溶液（６ｍＬ）を注入し、オートクレーブのベンゼン注入口を閉め、さらにオートクレーブの出口バルブを閉め、圧力が０．２０ＭＰａになったところでオートクレーブのフッ素ガス入り口バルブを閉めて、０．４時間撹拌を続けた。さらに、同様の操作を３回くり返した。ベンゼンの注入総量は０．３３ｇ、Ｒ−１１３の注入総量は３３ｍＬであった。さらに、窒素ガスを１．０時間吹き込んだ。目的物を^１９Ｆ−ＮＭＲで定量したところ、化合物（４ｂ−１）の生成が確認され、その収率は６４％であった。
^１９Ｆ−ＮＭＲ（３７６．０ＭＨｚ、ＣＤＣｌ_３、ＣＦＣｌ_３）δ（ｐｐｍ）：−８０．３（１Ｆ），−８１．９（３Ｆ），−８２．１（３Ｆ），−８３．５〜−８４．８（２Ｆ），−８５．５〜−８８．０（３Ｆ），−１２６．５（１Ｆ），−１２７．４（１Ｆ），−１２８．１（１Ｆ），−１３０．２（２Ｆ），−１３０．４（１Ｆ），−１３２．２（１Ｆ），−１３５．８（１Ｆ）。
［例３］エステル分解工程による化合物（５ａ−１）の製造例

例２で得た化合物（４ｂ−１）（２．１ｇ）をＮａＦ粉末（０．０２ｇ）と共にフラスコに仕込み、激しく撹拌を行いながらオイルバス中で１４０℃で１０時間加熱した。フラスコ上部には２０℃に温度調節した還流器を設置した。冷却後液状サンプル（２．０ｇ）を回収した。回収した液状サンプルを、化合物（４ｂ−１）の２．５倍モル量のＫＯＨを含むＫＯＨ水溶液中で反応させ、水を除去することによって化合物（５ａ−１）を得た。
［例４］化合物（６ｂ）の製造例
例３で得た化合物（５ａ−１）を文献（Ｚｈ．Ｏｒｇ．Ｋｈｉｍ．，１９７７，１３（１２），２５７３）と同様の方法でＫ_２ＣＯ_３とともに２２５℃に加熱したところ、化合物（６ｂ）を主生成物として得た。化合物（６ｂ）の収率は、７１．２％であった。生成物中には、化合物（６ａ）の存在も認められた。

［例５］還元工程による化合物（７ｂ）の製造例
例１〜４の反応を繰り返すことによって得られた化合物（６ｂ）を用いて、還元反応を行った。
表１に示す触媒（１００ｍＬ）インコネル６００製の反応管（直径１／２インチ、長さ１ｍ）に充填し、これを外部から過熱して１２０℃に保ち、化合物（６ｂ）を０．２ｍｏｌ／ｈの流速で導入し、同時に水素を１．０ｍｏｌ／ｈの流速で導入して反応を行った。反応器の出口ガスをＧＣで分析した結果、化合物（７ｂ）がそれぞれ下表１に示した成績で得られた。なお、触媒はいずれもヤシガラ破砕炭１００質量部に対して金属成分２質量部を担持させたものを用いた。

［例６］エステル化工程による化合物（３ａ−１）の製造例

例２における２−テトラヒドロフルフリルアルコール（２０ｇ）を２−フルフリルアルコール（２１ｇ）に変えること以外は例１と同様にエステル化工程を行い化合物（３ａ−１）の生成を確認した。
^１９Ｆ−ＮＭＲ（２８２．７ＭＨｚ，ＣＤＣｌ_３，ＣＦＣｌ_３）δ（ｐｐｍ）：−７９．９（１Ｆ），−８１．３（３Ｆ），−８２．１（３Ｆ），−８６．４（１Ｆ），−１２９．５（２Ｆ），−１３１．５（１Ｆ）。
［例７］フッ素化工程による化合物（４ｂ−１）の製造例

例２における化合物（３ｂ−１）を例６で得た化合物（３ａ−１）５．５ｇに変えること以外は、例２と同様にしてフッ素化工程を行った。
反応後のフッ素化物を^１９Ｆ−ＮＭＲで定量したところ、化合物（４ｂ−１）の生成が確認され、その収率は６４％であった。
^１９Ｆ−ＮＭＲ（３７６．０ＭＨｚ、ＣＤＣｌ_３、ＣＦＣｌ_３）δ（ｐｐｍ）：−８０．３（１Ｆ），−８１．９（３Ｆ），−８２．１（３Ｆ），−８３．５〜−８４．８（２Ｆ），−８５．５〜−８８．０（３Ｆ），−１２６．５（１Ｆ），−１２７．４（１Ｆ），−１２８．１（１Ｆ），−１３０．２（２Ｆ），−１３０．４（１Ｆ），−１３２．２（１Ｆ），−１３５．８（１Ｆ）。
［例８］エステル分解工程による化合物（５ａ−２）の製造例

例３におけるＫＯＨをＮａＯＨに変えること以外は例３のエステル分解工程と同様に反応を行い化合物（５ａ−２）を得た。
［例９］化合物（６ａ）の製造例

例４における化合物（５ａ−１）を、例８で得た化合物（５ａ−２）に変え、Ｋ_２ＣＯ_３をＮａ_２ＣＯ_３に変えること以外は例４と同様に反応を行い主成分として化合物（６ａ）を得た。化合物（６ａ）の収率は、６１．０％であった。また、生成物中には化合物（６ｂ）の生成も認められた。
［例１０］還元工程による化合物（７ａ）の製造例
例６〜９の反応を繰り返すことによって得た化合物（６ａ）を、化合物（６ｂ）を含むまま用いて、表２に示す触媒の存在下に例５と同様に還元工程を行い、化合物（７ａ）を得た。反応器の出口ガスをＧＣで分析した結果を下表２に示す。出口ガス中には、化合物（７ｂ）の存在も認められた。

［例１１］ドライエッチング剤としての評価例
（例１１−１）平行平板型プラズマエッチング装置中に、酸化シリコン膜を表面に形成した直径１５０ｍｍのシリコンウエハーをセットし、系内を真空にした後、例４の生成物から蒸留して得た化合物（６ｂ）をガス化させて、５０ｍｌ／分（ガス温度２０℃）にて導入した。系内の圧力を３９．９Ｐａ（絶対圧）に設定し、プラズマ密度１０^９ｃｍ^−３のプラズマを６０秒間照射してエッチング実験を行った。エッチング速度はウエハー上の任意の３点の膜圧をエッチング前後で測定し、３点のエッチング速度の平均が２０００オングストローム／分以上を○、それ以下を×とした。結果は○であった。
（例１１−２）化合物（６ａ）を例９で得た化合物（６ａ）に変更すること以外は、例１１−１と同様の測定を行った。結果は○であった。
（例１１−３）比較例
化合物（６ａ）をオクタフルオロシクロペンテンに変更すること以外は、例１１−１と同様の測定を行った。結果は×であり、エッチング反応は全く進まず、シリコンウエハー上に黄褐色の重合物がデポジットした。
［例１２］水切り乾燥溶剤としての評価例
ステンレスメッシュ（５ｃｍ×５ｃｍ）をあらかじめ洗浄し、つぎに水に浸漬したものを被洗浄物品とした。例１０で合成した化合物（７ａ）を化合物（７ｂ）を含むまま用いた。該化合物（７ｂ）にエタノールを添加してエタノール濃度を５質量％に調整した混合溶剤を調製した。
つぎに、被洗浄物を３０℃の混合溶剤に浸漬し、超音波を用いて１分間水切りを行った。次に化合物（７ａ）の蒸気ゾーンで３０秒間蒸気洗浄を行った。蒸気洗浄後の乾燥性と、浸漬水切り後の混合溶剤の状態と、浸漬水切り時の混合溶剤の液面に浮上する水の状態を観察し、つぎのＡ〜Ｄで判定した結果、Ａであった。Ａ；シミもなく完全乾燥である。Ｂ；乾燥しているがシミが若干あり。Ｃ；若干の水の残存あり。Ｄ；水が多く残存。
また、混合溶剤の状態を、つぎのＡ〜Ｄで判定した結果、Ａであった。Ａ；濁りがない、Ｂ；若干白濁が感じられる、Ｃ；やや白濁、Ｄ；強く白濁。
また液面に浮上する水の状態を、つぎのＡ〜Ｄで判定した結果、Ａであった。Ａ；速やかに浮上、Ｂ；やや浮上が遅い、Ｃ；浮上が遅い、Ｄ；水の浮上が極めて遅い。
［例１３］洗浄剤およびリンス剤としての評価例
予めよく洗浄したステンレスメッシュ（５ｃｍ×５ｃｍ）に、切削油（商品名：ダフニカットＡＳ−４０Ｈ。出光興産社製）を塗布して、１００℃で１時間加熱したものを被洗浄物品とした。
被洗浄物をイソドデカン（６０℃）に３０秒間浸漬洗浄し、次に例１０で得た化合物（７ａ）を化合物（７ｂ）を含むまま用いた。該化合物（７ａ）を用いて３０℃で３０秒間浸漬リンスして、最後に化合物（７ａ）の蒸気ゾーンで３０秒間蒸気洗浄を行った。
切削油を塗布前と塗布後、また洗浄乾燥後の被洗浄物の質量測定結果から、切削油の残存率を算出し、また蒸気洗浄直後の被洗浄物の乾燥状態を観察し、つぎの基準で評価した結果、Ａであった。油の残存率がＡ；０．１重量％未満、Ｂ；０．１重量％以上０．５重量％未満、Ｃ；０．５重量％以上２重量％未満、Ｄ；２重量％以上。また、乾燥状態をつぎの基準で評価した結果、Ａであった。Ａ；ただちに乾燥、Ｂ；ゆっくり乾燥、Ｃ；部分的に乾燥、Ｄ；乾燥できず。
＜産業上の利用可能性＞
本発明は、工業的実施に適した方法であり、かつ、経済的に有利な方法で、収率よくフッ素化環状エーテルを製造する方法を提供する。本発明のフッ素化環状エーテルは、水切り乾燥溶剤、ドライエッチング剤、または洗浄剤等の機能剤として有用な化合物である。また本発明によれば、フッ素化環状エーテルの中間体として有用な新規な化合物が提供される。<Technical field>
The present invention relates to a method for producing industrially useful fluorinated cyclic unsaturated ethers and fluorinated saturated cyclic ethers (hereinafter collectively referred to as fluorinated cyclic ethers) and uses thereof, and an intermediate process for producing the fluorinated cyclic ethers. It relates to a novel compound useful as a body.
<Background technology>
The following method is known as a method for synthesizing a fluorinated cyclic ether.
(1) Tetrahydrofuran is converted to CoF₃(Journal of Chemical Soc. C, 1969, (13), 1739). However, this method has a problem that 30 or more compounds are formed and the selectivity of the target product is extremely low.
(2) The potassium salt of perfluoro (tetrahydrofuranyl-2-carboxylic acid) is₂CO₃Pyrolysis in the presence (Zh. Org. Khim., 1977, 13 (12), 2573). However, potassium salts of perfluoro (tetrahydrofuranyl-2-carboxylic acid) are difficult to obtain, and it has been difficult to apply the method to industrial production.
That is, the conventional method for producing a fluorinated cyclic ether has problems such as low yield, difficulty in scale-up, and the need for expensive raw materials. Had not been.
An object of the present invention is to provide a method for producing a fluorinated cyclic ether in a yield that is a method suitable for industrial practice and economically advantageous in a high yield.
<Disclosure of the Invention>
The present invention provides a method for producing a fluorinated cyclic ether useful as a functional agent or the like using a compound that can be obtained at low cost. Further, the present invention provides an industrially useful continuous process by recycling the fluoride compound obtained in the step of the ester decomposition reaction in the production method. Further, the present invention provides a novel compound useful as an intermediate for producing a fluorinated cyclic ether. Furthermore, the fluorinated cyclic ether produced by the present invention has excellent properties as an alternative compound of chlorofluorocarbons (CFC), has zero ozone depletion potential (ODP), and has extremely low global warming potential (GWP). The present inventors have found that the compound is small, and provide a useful use of the fluorinated cyclic ether.
That is, the present invention provides each invention having the following configurations.
1. A compound represented by the following formula (5) is thermally decomposed to form at least one fluorinated unsaturated cyclic ether selected from a compound represented by the following formula (6a) and a compound represented by the following formula (6b): A method for producing a fluorinated unsaturated cyclic ether, characterized by being obtained.
However, A^FRepresents a perfluorotetrahydrofuranyl group. X is a fluorine atom or -O⁻M⁺(However, M⁺Represents a counter ion. ).
A^FCOX (5)

2. 2. The method according to the above 1, wherein the compound represented by the formula (5) is a compound represented by the following formula (5a).

3. A compound represented by the following formula (5f) in which X in the compound represented by the formula (5) is a fluorine atom, is a compound represented by the following formula (1) and a compound represented by the following formula (2). Reacting to a compound represented by the following formula (3), and fluorinating the compound represented by the formula (3) to a compound represented by the following formula (4), and represented by the formula (4) 3. The production method according to the above 1 or 2, which is a compound obtained by a decomposition reaction of an ester bond of the compound.
However, A^FHas the same meaning as described above. R^CRepresents a monovalent organic group. R^CFIs R^CThe same monovalent organic group as^CRepresents a fluorinated monovalent organic group. X¹Represents a halogen atom. A represents a group represented by a formula selected from the following formulas (1a), (1b), (1c), and (1d), or one or more hydrogen atoms in the selected formula. It shows the group represented by the formula substituted by a fluorine atom.
ACH₂OH (1)
R^CCOX¹  (2)
ACH₂OCOR^C  (3)
A^FCF₂OCOR^CF  (4)
A^FCOF (5f)

4. The compound represented by the formula (1) is a compound represented by the following formula (1), the compound represented by the formula (3) is a compound represented by the following formula (3), and the compound represented by the formula (4) A in the compound represented by^FIs a 2-perfluorotetrahydrofuranyl group, and the compound represented by the formula (5f) is a compound represented by the following formula (5a).
Where R^CHas the same meaning as described above. A¹Is a group represented by a formula selected from the following formulas (1a-1), (1b-1), (1c-1), and (1d-1); A group represented by the formula in which one or more hydrogen atoms have been replaced by fluorine atoms.
A¹CH₂OH (1)
A¹CH₂OCOR^C  (3)

5. A compound represented by the formula (3) is converted to a compound represented by the formula (5) and a compound represented by the following formula (2a) from a reaction product obtained by subjecting an ester bond of the compound represented by the formula (4) to a decomposition reaction. The method according to 3 or 4, which is a compound obtained by obtaining a compound represented by the formula (2a) and reacting the compound represented by the formula (2a) with a compound represented by the formula (1).
Where R^CFHas the same meaning as described above.
R^CFCOF (2a)
6. 6. The method according to 3, 4, or 5, wherein the fluorination is carried out by reacting with fluorine in a liquid phase.
7. A compound represented by the following formula (5) is thermally decomposed to obtain one or more compounds selected from a compound represented by the following formula (6a) and a compound represented by the following formula (6b). The compound represented by the formula (6a) was reduced by performing a reduction reaction of the one or more compounds, and the compound represented by the following formula (7a) and the compound represented by the formula (6b) were reduced. A method for producing a fluorinated saturated cyclic ether, comprising obtaining one or more fluorinated saturated cyclic ethers selected from the compounds represented by the formula (7b).
However, A^FAnd X each have the same meaning as described above.
A^FCOX (5)

8. The method according to the above 7, wherein the compound represented by the formula (5) is a compound represented by the following formula (5a).

9. Any compound represented by the following formula.

Where R^C1And R^CF1Represents a perfluoroalkyl group, a perfluoro (partial chloroalkyl) group, a perfluoro (etheric oxygen atom-containing alkyl) group, a perfluoro (partial chloro (etheric oxygen atom-containing alkyl)) group, or a perfluorotetrahydrofuranyl group.
10. One or more fluorinated unsaturated cyclic ethers selected from the compound represented by the following formula (6a) and the compound represented by the following formula (6b), or the compound represented by the following formula (7a) and the following formula A functional agent containing at least one fluorinated saturated cyclic ether selected from the compounds represented by (7b).

11. A functional agent containing a compound represented by the following formula (7a).

12. 12. The functional agent according to the above 10 or 11, which is a draining dry solvent, a dry etching agent, or a cleaning agent.
<Best mode for carrying out the invention>
In the following description of the present specification, the compound represented by the formula (5) is referred to as a compound (5). The same applies to compounds represented by other formulas.
In the present invention, the following compound (5) is thermally decomposed to obtain one or more fluorinated unsaturated cyclic ethers selected from the following compound (6a) and the following compound (6b).
A^FCOX (5)

A in equation (5)^FRepresents a perfluorotetrahydrofuranyl group. The -COX group in the compound (5) is a perfluorotetrahydrofuranyl group (A^F) May be bonded to the 2-position or the 3-position, and is preferably bonded to the 2-position. That is, A^FIs preferably a 2-perfluorotetrahydrofuranyl group, and as the compound (5), the following compound (5a) is preferable.

X is a fluorine atom or -O⁻M⁺Is shown. M⁺Is selected from cations capable of forming a salt with a carboxylic acid, preferably an alkali metal cation;⁺, Na⁺Is particularly preferred. X in compound (5) is -O⁻M⁺As a method for producing a compound represented by the formula (1), a method of converting a -COF group of the compound (5f) wherein X of the compound (5) is a fluorine atom to -COOH to form a salt, or a method of preparing the compound (5f) by adding 2 More than twice the molar amount of MOH (M⁺And an alkali metal atom is preferred. ), And then drying by heating under reduced pressure.
Among the compounds (5) that are substrates for the thermal decomposition reaction, the following compound (5f) in which X is a fluorine atom is obtained by reacting the compound (1) with the compound (2) to form a compound (3). ) Is fluorinated to give a compound (4), which is preferably a compound obtained by subjecting an ester bond of the compound (4) to a decomposition reaction. However, A^FHas the same meaning as described above. R^CRepresents a monovalent organic group. R^CFIs R^CThe same monovalent organic group as^CRepresents a fluorinated monovalent organic group. X¹Represents a halogen atom. A represents a group represented by a formula selected from the following formulas (1a), (1b), (1c), and (1d), or one or more hydrogen atoms in the selected formula. It shows the group represented by the formula substituted by a fluorine atom.
ACH₂OH (1)
R^CCOX¹  (2)
ACH₂OCOR^C  (3)
A^FCF₂OCOR^CF  (4)
A^FCOF (5f)

Further, X of the compound (5) is -O⁻M⁺Can be produced from the compound (5f) by the method described above.
The esterification reaction between the compound (1) and the compound (2), the fluorination reaction of the compound (3), and the ester bond decomposition reaction of the compound (4) are described in WO00 / 56694 by the present inventors. Can be carried out in the same manner and under the same conditions as in the above method. According to the method, the compound (5) can be produced extremely efficiently and industrially from inexpensive compounds (1) and (2).
In the above formulas (1a) to (1d), the line extending from the ring is a bond (the position of the carbon atom of the 5-membered ring to which the bond is bonded is not limited), and these groups are monovalent. It shows that it is a group of. That is, the compound (1) is -CH₂A compound in which an OH group is bonded to the 2- or 3-position of the group represented by the formulas (1a) to (1c), or -CH₂It shows a compound in which an OH group is bonded to any of the 2-position to the 5-position of the group represented by the formula (1d).
A is -CH at the 2-position₂A group having a bond to OH, that is, a group selected from the following formulas (1a-1), (1a-2), (1a-3), and (1a-4) Or a group represented by the formula wherein at least one hydrogen atom in the selected formula is replaced by a fluorine atom (A¹Is preferred.

A is preferably a group having no fluorine atom, that is, a group represented by a formula selected from formulas (1a), (1b), (1c), and (1d). The group represented by the formula or the group represented by the formula (1b) is preferable, and the group represented by the formula (1a-1) or the group represented by the formula (1a-2) is particularly preferable.
Specific examples of the compound (1) include the following compounds.

In the compound (2) reacted with the compound (1), R^CRepresents a monovalent organic group. R^CFrom the viewpoint of solubility in the liquid phase used during the fluorination reaction, a group having 1 to 20 carbon atoms is preferable, and a group having 1 to 10 carbon atoms is particularly preferable. Further R^CIs preferably a group containing a fluorine atom (ie, a fluoromonovalent organic group), such as a fluoroalkyl group, a fluoro (partial chloroalkyl) group, a fluoro (etheric oxygen atom-containing alkyl) group, and a fluoro (partial chloro ( Etheric oxygen atom-containing alkyl)) group, or A^FIs preferred. Further, R^CIs preferably a perfluoromonovalent organic group, a perfluoroalkyl group, a perfluoro (partial chloroalkyl) group, a perfluoro (etheric oxygen atom-containing alkyl) group, a perfluoro (partial chloro (etheric oxygen atom-containing alkyl)) group, Or A described later^FIs particularly preferred. However, a partially chlorinated group refers to a group that has been substituted with chlorine to the extent that a hydrogen atom remains.
Specific examples of the compound (2) include the following compounds. However, A^FRepresents a perfluorotetrahydrofuranyl group, and is preferably a perfluoro (2-tetrahydrofuranyl) group.
CF₃CF₂COF,
CF₃CF₂CF₂OCF (CF₃) COF,
CF₃CF₂CF₂OCF (CF₃) CF₂OCF (CF₃) COF,
A^FCOF
As the compound (2), a commercially available product may be used, but the compound (2a) (R), which is a compound that can be produced together with the compound (5) in a decomposition reaction of an ester bond of the compound (4) described below.^CFCOF (2a)) may be used. The method using compound (2a) as compound (2) is particularly preferable because it can be a continuous production method. That is, R in compound (2)^CIs R^CFAnd preferably the same group as^CIs preferably a perfluoromonovalent organic group. Preferred embodiments of the perfluoromonovalent organic group are as described above.
In addition, R in compound (2)^CIs A^FIn other words, when the compound (5) is used as the compound (2), the step of separating the product is only the compound (5) produced by the decomposition reaction of the ester bond of the compound (4). Is preferred because it has the advantage of not being necessary.
The esterification reaction between compound (1) and compound (2) may be carried out in the presence of a solvent, but is preferably carried out in the absence of a solvent from the viewpoint of volumetric efficiency. In addition, since HF is generated in the reaction between the compound (1) and the compound (2), an alkali metal fluoride (preferably NaF, KF or the like), a trialkylamine, or the like is present in the reaction system as a HF scavenger. HF scavengers are preferably present. When the HF scavenger is not used, it is preferable to discharge HF out of the reaction system together with the nitrogen stream. When the alkali metal fluoride is used, it is preferable to use 1 to 10 moles per mole of the compound (2).
The reaction temperature between compound (1) and compound (2) is preferably from -50C to + 100C. The reaction time of the reaction can be appropriately changed depending on the supply rate of the raw materials and the amount of the compound used in the reaction. The reaction pressure (gauge pressure, hereinafter the same) is preferably from 0 to 2 MPa.
The amount ratio of the compound (1) to the compound (2) is preferably such that the amount of the compound (2) is 0.5 to 5 times, more preferably 1 to 2 times, the mole of the compound (1). .
The crude product containing the compound (3) produced by the reaction between the compound (1) and the compound (2) may be purified according to the purpose or used as it is for the next reaction or the like. From the viewpoint of stably performing the fluorination reaction in the step, it is desirable to separate and purify the compound (3) in the crude product.
As a method for purifying the crude product, a method for distilling the crude product as it is, a method for treating the crude product with diluted alkaline water or the like to separate the crude product, and a method for extracting the crude product with an appropriate organic solvent and then distilling Method, silica gel column chromatography and the like.
Specific examples of the compound (3) include the following compounds. However, A¹And A^FHas the same meaning as described above.
CF₃CF₂CF₂OCF (CF₃) COOCH₂A¹,
CF₃CF₂CF₂OCF (CF₃) CF₂OCF (CF₃) COOCH₂A¹,
A^FCOOCH₂A¹
In the present invention, the compound (3) is fluorinated. As a method of the fluorination reaction, CoF₃, An ECF method, or a method using a fluorine gas, and a liquid phase fluorination method performed by introducing a fluorine gas into a liquid phase is preferable. In the fluorination reaction, one or more fluorine atoms are bonded to the molecule of the compound (3). Hereinafter, an example in which the fluorination reaction is carried out by a liquid phase fluorination reaction will be described.
The fluorine gas in the liquid phase fluorination reaction may be used as it is or may be a fluorine gas diluted with an inert gas such as nitrogen gas. When a diluted fluorine gas is used, the fluorine gas concentration is preferably at least 10 vol%, particularly preferably at least 20 vol%.
Fluorine (F₂) Is preferably formed from a solvent capable of dissolving As the solvent, it is preferable to use a solvent having high solubility of the compound (3), particularly a solvent capable of dissolving the compound (3) by 1% by mass or more, particularly preferably a solvent dissolving the compound (3) by 5% by mass or more. . The amount of the solvent is preferably at least 5 times, more preferably 10 to 100 times the mass of the compound (3).
Examples of solvents that can be used for liquid phase fluorination include perfluoroalkanes, perfluoroethers, perfluoropolyethers, chlorofluorocarbons, chlorofluoropolyethers, perfluoroalkylamines, inert fluids, and the like. It is particularly preferable to use the compound (4), the compound (5) or the compound (2a) which has an advantage that post-treatment after the reaction is facilitated.
The fluorine content (the fluorine content is the ratio of the mass of fluorine atoms to the molecular weight) of the compound (3) is preferably at least 10% by mass, particularly preferably from 10 to 86% by mass. If the fluorine content is too low, the solubility in the liquid phase becomes extremely low, and the reaction system of the fluorination reaction becomes heterogeneous. When the reaction is carried out in a continuous reaction, the compound (3) is successfully fed into the reaction system. There are problems such as being unable to do so. Further, the upper limit of the fluorine content is not limited, but if it is too high, it is difficult to obtain compound (3), the price is high, and it is not economical.
Further, the molecular weight of the compound (3) is preferably from 200 to 1,000 in that an undesirable fluorination reaction in the gas phase is prevented and the liquid phase fluorination reaction can be carried out smoothly. If the molecular weight is too small, the compound (3) is likely to evaporate, so that a decomposition reaction may occur in a gas phase during a fluorination reaction in a liquid phase. On the other hand, if the molecular weight is too large, purification of compound (3) may be difficult.
The reaction system of the fluorination reaction may be a batch system or a continuous system. In particular, the continuous method is preferable from the viewpoint of the reaction yield and the selectivity. Further, the fluorine gas may be diluted with an inert gas such as nitrogen gas in both cases of the batch system and the continuous system.
In the fluorination reaction, it is preferable to charge fluorine gas such that the amount of fluorine is always in excess equivalent to the hydrogen atom in the compound (3), particularly 1.5 times equivalent or more (that is, 1.5 times equivalent). It is preferable from the viewpoint of selectivity that the fluorine gas is used so that the molar ratio becomes twice or more. It is preferable that the fluorine gas always keeps an excess equivalent from the start point to the end point of the reaction. For that purpose, it is preferable to introduce the compound (3) into a liquid phase in which fluorine is dissolved.
The reaction temperature of the liquid-phase fluorination reaction is usually preferably from -60 ° C to the boiling point of the compound (3), and from -50 ° C to +100 in view of the reaction yield, selectivity, and ease of industrial implementation. C is particularly preferred, and -20 C to +50 C is particularly preferred. The reaction pressure of the fluorination reaction is particularly preferably 0 to 2 MPa from the viewpoint of the reaction yield, the selectivity, and the ease of industrial implementation.
Furthermore, in the liquid-phase fluorination reaction, it is preferable to add a C—H bond-containing compound to the reaction system or to irradiate ultraviolet rays in order to efficiently advance the fluorination.
As the CH bond-containing compound, aromatic hydrocarbons are preferable, and benzene, toluene and the like are particularly preferable. The amount of the C—H bond-containing compound to be added is preferably 0.1 to 10 mol%, particularly preferably 0.1 to 5 mol%, based on hydrogen atoms in compound (3). The C—H bond-containing compound is preferably added in a state where fluorine gas is present in the reaction system. Further, when a CH bond-containing compound is added, it is preferable to pressurize the reaction system. The pressure at the time of pressurization is preferably 0.01 to 5 MPa.
In the fluorination reaction, HF is produced as a by-product, so that an HF scavenger is allowed to coexist in the reaction system for the purpose of removing the by-produced HF, or the HF scavenger is brought into contact with the outlet gas at the reactor gas outlet. Is preferred. Examples of the HF scavenger include the same examples as described above, and NaF is preferable.
When the HF scavenger is present in the reaction system, the amount thereof is preferably 1 to 20 moles, and more preferably 1 to 5 moles relative to the total amount of hydrogen atoms present in the compound (3).
The crude product containing the compound (4) obtained by the fluorination reaction may be used as it is in the next step, or may be purified to high purity. Examples of the purification method include a method of distilling the crude product as it is under normal pressure or reduced pressure.
Compound (4) is a compound obtained by fluorinating compound (3), and preferably a compound obtained by perfluorinating compound (3).
In the fluorine reaction, a reaction in which CH is converted to CF or a reaction in which fluorine is added to an unsaturated bond occurs. A in the resulting compound (4)^FIs a group corresponding to A,^CFIs R^CIn these groups, there is no change in the arrangement of carbon atoms before and after the fluorination reaction, and a compound corresponding to the compound (3) is obtained. However, when there is a carbon-carbon unsaturated bond in the compound (3), the bonding state may be changed by adding a fluorine atom to one or more of the unsaturated bonds. R^CFAs the above R^CAnd a perfluoromonovalent organic group is particularly preferred. A perfluoroalkyl group, a perfluoro (partial chloroalkyl) group, a perfluoro (etheric oxygen atom-containing alkyl) group, and a perfluoro (partial chloro (etheric oxygen atom-containing alkyl) group )) Groups or perfluorotetrahydrofuranyl groups are particularly preferred. Specific examples of the compound (4) include the following compounds. However, A^FHas the same meaning as described above.
CF₃CF₂CF₂OCF (CF₃) COOCF₂A^F,
CF₃CF₂CF₂OCF (CF₃) CF₂OCF (CF₃) COOCF₂A^F,
A^FCOOCF₂A^F.
The compound (4) is converted into a compound (5) in which X is a fluorine atom by a decomposition reaction of an ester bond. The decomposition reaction of the ester bond can be carried out by heating, or by reacting with an electrophile or in the presence of a nucleophile. When the ester bond is decomposed by heating, the type of reaction can be selected depending on the boiling point and stability of compound (4).
When the compound (4) is a compound which is easily vaporized, it is preferably carried out by a gas phase method of continuously decomposing in a gas phase and condensing and recovering an outlet gas containing the obtained compound (5). . The reaction temperature of the gas phase method is preferably from 50 to 350C, particularly preferably from 50 to 300C, particularly preferably from 150 to 250C. In the gas phase method, an inert gas which is not directly involved may coexist in the reaction system. Examples of the inert gas include a nitrogen gas and a carbon dioxide gas. The amount of the inert gas is preferably about 0.01 to 50% based on the compound (4). If the amount of the inert gas is large, the amount of the recovered product may decrease.
When the decomposition reaction of the ester bond is performed by a gas phase method, it is preferable to use a tubular reactor. When a tubular reactor is used, the residence time is preferably about 0.1 seconds to 10 minutes on an empty tower basis. In the gas phase reaction using a tubular reactor, it is preferable to fill the reaction tube with a glass, an alkali metal salt, or an alkaline earth metal salt for the purpose of accelerating the reaction. The reaction pressure is not particularly limited, but when the compound (4) is a high-boiling compound, the reaction is preferably performed under reduced pressure. On the other hand, when the compound (4) is a low-boiling compound, it is preferable to carry out the reaction under pressure because decomposition of the product is suppressed and the reaction rate increases.
On the other hand, when the compound (4) is a compound that is difficult to vaporize, it is preferable to employ a liquid phase method in which the liquid is heated in the reactor as it is. The reaction pressure of the method is not limited. The product containing the fluorinated cyclic ether (5) may be collectively extracted from the reactor after the completion of the heating, but since the fluorinated cyclic ether (5) has a lower boiling point than the compound (4), It is preferable to employ a method of vaporizing and continuously extracting. The reaction temperature in the liquid phase method is preferably from 50 to 300 ° C, particularly preferably from 100 to 250 ° C. In the liquid phase method, a solvent may or may not be present, and the absence of a solvent is preferable from the viewpoint of volumetric efficiency and suppression of by-products.
When the ester bond decomposition reaction is performed by a method of reacting with a nucleophile or an electrophile in a liquid phase, a solvent may or may not be present in the reaction. It is preferable from the viewpoint of volumetric efficiency and suppression of byproducts. As a nucleophile, a fluorine anion (F⁻) Is preferable, and a fluorine anion derived from an alkali metal fluoride is particularly preferable. As the alkali metal fluoride, NaF, KF and CsF are preferable, and NaF is particularly preferable from the viewpoint of economy. The nucleophile may be used in a catalytic amount or in excess. The amount of the nucleophile is preferably from 1 to 500 mol%, particularly preferably from 10 to 100 mol%, particularly preferably from 5 to 50 mol%, based on the compound (4). The lower limit of the reaction temperature is preferably −30 ° C., and the upper limit is preferably the boiling point of the solvent or the boiling point of the compound (4). The usual reaction temperature is particularly preferably from -20C to 250C. Also in this method, it is preferable to carry out the reaction while continuously taking out the produced compound (5).
The reaction product of the ester decomposition reaction contains the compound (2a) together with the compound (5). When the compound (2a) is different from the compound (5), the compound (2a) can be separated from the compound (5) and used for another purpose. Compound (2a) is a useful intermediate that can be converted into another useful compound.
Further, when the esterification reaction is carried out by using the compound (2a) as the compound (2) to be esterified with the compound (1), the compound (3) can be produced, and the compound (3) can be produced by the method described above. Thus, compound (5) can be produced. For example, compound (2a) is a compound represented by R in compound (2)^CIs R^CFWherein X is a fluorine atom. Compound (5) can be produced by reusing compound (2a) as compound (2).
In the present invention, the compound (5) is thermally decomposed. The reaction conditions for the thermal decomposition are not particularly limited. For example, the thermal decomposition reaction is preferably performed by a thermal decomposition reaction in a gas phase.
When X of the compound (5) is a fluorine atom, the reaction temperature of the gas phase thermal decomposition reaction is preferably from 250 to 400 ° C, more preferably from 280 to 350 ° C. X is -O⁻M⁺In this case, the reaction temperature in the gas phase thermal decomposition reaction is preferably from 150 to 300C, more preferably from 200 to 280C. If the reaction temperature in the gas phase pyrolysis reaction is too low, the conversion tends to be low. On the other hand, if the reaction temperature in the gas phase thermal decomposition reaction is too high, the amount of generation other than the target compound tends to increase.
In the thermal decomposition reaction of compound (5), a COFX removal reaction occurs, a double bond is formed in the furan ring, and compound (6a) or compound (6b) is generated. Further, in these compounds, a transfer reaction of a double bond may further occur, and a compound (6b) may be produced from the compound (6a), and a compound (6a) may be produced from the compound (6b). For example, in the thermal decomposition reaction of the compound (5) in which -COF is bonded to the 2-position, a compound (6a) is generated. In the thermal decomposition reaction of the compound (5) in which -COF is bonded to the 3-position, the compound ( 6b) is generated. Further, when a double bond transfer reaction occurs in a part of the product, the product can be a compound (6a) or a compound (6b). In the thermal decomposition reaction, two kinds of compounds are usually generated. In particular, X is -O⁻K⁺Is a compound (6b) from the compound (5) represented by⁻Na⁺Compound (6a) tends to be preferentially produced from compound (5) represented by
The composition of the product of the thermal decomposition reaction can vary depending on the reaction conditions and the like. When the product is both the compound (6a) and the compound (6b), the composition is not particularly limited.
The compound (6a) and the compound (6b) may be used as they are for the intended use, but usually used after being converted into another compound. When two kinds of compounds are formed, the compound (6a) and the compound (6b) may be separated and purified and then converted to another compound. Since the boiling points are close and the separation is troublesome, it is preferable to convert them to other compounds without separating them.
Further, in the present invention, the following compound (7a) and compound (6b) in which compound (6a) is reduced by performing a reduction reaction on at least one compound selected from compound (6a) and compound (6b) To obtain at least one kind of fluorinated saturated cyclic ether selected from the compound (7b) in which is reduced.

In the reduction reaction, a hydrogen atom is added to the carbon-carbon unsaturated double bond of compound (6a) or compound (6b). This reduction reaction is preferably performed using hydrogen, and particularly preferably performed using hydrogen in the presence of a catalyst. As the catalyst, a metal-supported catalyst is preferable. The metal-supported catalyst is preferably a catalyst having 0.5 to 5% by weight, preferably 1 to 3% by weight of a metal supported on a carrier. Further, the metal-supported catalyst is preferably a catalyst in which a metal is supported on activated carbon, and an activated carbon catalyst in which palladium is supported, an activated carbon catalyst in which palladium as a main component and a Group 8 element other than palladium, or an Au-supported catalyst Particularly preferred are activated carbon catalysts.
Here, as the Group 8 element other than palladium, at least one element selected from Fe, Co, Ni, Ru, Rh, Ir, and Pt is preferable. The amount of Group 8 element other than palladium is preferably 0.01 to 50% by mass based on palladium. When the carrier is activated carbon, activated carbon derived from plant material is preferred over activated carbon derived from mineral substances, and coconut shell activated carbon is particularly preferred. The shape of the carrier may be shaped coal having a length of about 2 to 5 mm, crushed coal having a length of about 4 to 50 mesh, granular coal, or the like, and may be crushed coal having a length of about 4 to 20 mesh or a length of about 2 to 2 mesh. A formed coal of about 5 mm is preferred.
The catalyst in which a metal is supported on activated carbon is preferably prepared by a method in which a metal component is supported on a carrier, dried, and then activated by reduction with hydrogen. The catalyst prepared by this method has the advantages of high durability and no need for activation even when used for a long time. In the case of activation, it is preferable to adopt a method of hydrogen reduction at 100 to 300 ° C (particularly 200 to 300 ° C).
The amount of hydrogen is preferably at least 2 times the molar amount of the stoichiometric amount based on the total amount of the substrate for the reduction reaction, and more preferably 3 to 8 times the molar amount of the target compound in high yield. This is preferred.
The temperature of the reduction reaction is preferably from 130 to 250 ° C at normal pressure, particularly preferably from 150 to 200 ° C. The reaction pressure is not particularly limited. The reaction time of the reduction reaction is preferably 4 to 60 seconds, particularly preferably 8 to 40 seconds, in terms of the contact time with the catalyst. Further, the reduction reaction may be performed while diluting hydrogen with an inert gas such as nitrogen in order to control an excessive rise in temperature.
In the reduction reaction, when compound (6a) is reduced, compound (7a) is reduced, and when compound (6b) is reduced, compound (7b) is reduced when compound (6a) and compound (6b) are reduced. Produces a product consisting of the compound (7a) and the compound (7b). The composition of the product of the reduction reaction varies depending on the composition of the substrate of the reduction reaction.
When the product of the reduction reaction consists of the compound (7a) and the compound (7b), these may be used for the intended use as they are, or may be separated. Since the compound (7a) and the compound (7b) have different boiling points, it is preferable to separate them by a distillation method when separating them. Further, when the products of the thermal decomposition reaction are the compound (6a) and the compound (6b), and when the compound desired to be obtained by the reduction reaction is the compound (7a), the compound (6a) is subjected to distillation separation after the reduction reaction to obtain the compound ( It is preferred to obtain 7a).
Compound (6a), compound (6b), compound (7a) and compound (7b) obtained by the production method of the present invention have excellent properties as substitutes for chlorofluorocarbons, and have an ozone destruction coefficient of zero. It has a very low global warming potential. These compounds or a mixture of one or more of these compounds is a compound useful as a functional agent.
Examples of the functional agent include a refrigerant, a cleaning agent, a draining dry solvent, a solvent, a polymerization solvent, a dry etching agent, and a resin foaming agent. Among them, the functional agent containing one or two kinds of fluorinated unsaturated cyclic ethers selected from the compound (6a) and the compound (6b) is preferably used as a draining dry solvent, a dry etching agent, or a cleaning agent. Further, a functional agent containing one or two kinds of fluorinated saturated cyclic ethers selected from the compound (7a) and the compound (7b), particularly a functional agent containing the compound (7a), is preferably used as a dry etching agent.
Since oxygen atoms are present in the structure of the fluorinated cyclic ether of the present invention, when this is used as a dry etching agent, there is an advantage that the oxygen addition operation during dry etching can be omitted.
Further, according to the present invention, the following compound useful as an intermediate of the functional agent can be provided.

Where R^C1And R^CF1Represents a perfluoroalkyl group, a perfluoro (partial chloroalkyl) group, a perfluoro (etheric oxygen atom-containing alkyl) group, a perfluoro (partial chloro (etheric oxygen atom-containing alkyl)) group, or a perfluorotetrahydrofuranyl group, respectively. . R^C1And R^CF1Is preferably a group having 1 to 20 carbon atoms, particularly preferably a group having 1 to 10 carbon atoms. Further R^C1And R^CF1Preferable are a perfluoroalkyl group and a perfluoro (ether-based oxygen atom-containing alkyl group).
Example
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In the following, gas chromatography is referred to as GC, and gas chromatography mass spectrometry is referred to as GC-MS. The purity determined from the GC peak area ratio is referred to as GC purity, and the yield is referred to as GC yield. The yield determined from the peak area ratio of the NMR spectrum is referred to as NMR yield. Also, tetramethylsilane is replaced with TMS, CCl₂FCClF₂Is denoted as R-113. The NMR spectrum data is shown as an apparent chemical shift range.
[Example 1] Production example of compound (3b-1) by esterification step

2-Tetrahydrofurfuryl alcohol (20 g) and triethylamine (21.8 g) were placed in a flask and stirred in an ice bath. FCOCF (CF₃) OCF₂CF₂CF₃(71.5 g) was added dropwise over 1 hour while maintaining the internal temperature at 10 ° C or lower. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours, and water (50 mL) was added at an internal temperature of 15 ° C or lower.
The obtained crude liquid was separated, and the lower layer was washed twice with water (50 mL), dried over magnesium sulfate, and then filtered to obtain a crude liquid. The desired ester compound (66.3 g) was obtained by distillation under reduced pressure as a fraction at 88 to 89 ° C./2.7 kPa (absolute pressure). GC purity was 98%. The formation of compound (3b-1) was confirmed by NMR analysis.
¹H-NMR (300.4 MHz, CDCl₃, TMS) δ (ppm): 1.60-1.73 (m, 1H), 1.86-2.10 (m, 3H), 3.76-3.91 (m, 2H), 4.14 -4.22 (m, 1H), 4.28-4.47 (m, 2H).
¹⁹F-NMR (282.7 MHz, CDCl₃, CFCl₃) Δ (ppm): -79.9 (1F), -81.3 (3F), -82.1 (3F), -86.4 (1F), -129.5 (2F), -131.5 (1F).
[Example 2] Production example of compound (4b-1) by fluorination step

R-113 (313 g) was added to a 500 mL nickel autoclave, stirred, and kept at 25 ° C. At the autoclave gas outlet, a cooler maintained at 20 ° C, a packed bed of NaF pellets, and a cooler maintained at 10 ° C were installed in series. In addition, a liquid return line for returning the aggregated liquid from the cooler kept at -10 ° C to the autoclave was installed. After blowing nitrogen gas for 1.0 hour, fluorine gas diluted to 20% with nitrogen gas was blown at a flow rate of 8.08 L / h for 1 hour. Next, while blowing fluorine gas at the same flow rate, a solution in which the compound (3b-1) (5.01 g) obtained in Example 1 was dissolved in R-113 (100 g) was injected over 4.7 hours.
Then, while blowing fluorine gas at the same flow rate, an R-113 solution (9 mL) having a benzene concentration of 0.01 g / mL was injected while the temperature was raised from 25 ° C to 40 ° C, and the benzene inlet of the autoclave was closed. Further, the outlet valve of the autoclave was closed. When the pressure reached 0.20 MPa, the fluorine gas inlet valve of the autoclave was closed, and stirring was continued for 0.4 hours. Then, the pressure was adjusted to normal pressure, the above-mentioned benzene solution (6 mL) was injected while keeping the temperature in the reactor at 40 ° C., the benzene inlet of the autoclave was closed, and the outlet valve of the autoclave was closed. When the pressure reached 20 MPa, the fluorine gas inlet valve of the autoclave was closed, and stirring was continued for 0.4 hours. Further, the same operation was repeated three times. The total amount of benzene injected was 0.33 g, and the total amount of R-113 injected was 33 mL. Further, nitrogen gas was blown for 1.0 hour. The object¹⁹When quantified by F-NMR, formation of compound (4b-1) was confirmed, and the yield was 64%.
¹⁹F-NMR (376.0 MHz, CDCl₃, CFCl₃) Δ (ppm): -80.3 (1F), -81.9 (3F), -82.1 (3F), -83.5 to -84.8 (2F), -85.5 to -88 0.0 (3F), -126.5 (1F), -127.4 (1F), -128.1 (1F), -130.2 (2F), -130.4 (1F), -132.2 (1F), -135.8 (1F).
[Example 3] Production example of compound (5a-1) by ester decomposition step

The compound (4b-1) (2.1 g) obtained in Example 2 was charged into a flask together with NaF powder (0.02 g), and heated at 140 ° C. for 10 hours in an oil bath with vigorous stirring. At the top of the flask, a reflux condenser adjusted to 20 ° C. was installed. After cooling, a liquid sample (2.0 g) was collected. The collected liquid sample was reacted in an aqueous KOH solution containing 2.5 times the molar amount of KOH of compound (4b-1), and water was removed to obtain compound (5a-1).
[Example 4] Production example of compound (6b)
Compound (5a-1) obtained in Example 3 was converted to K by a method similar to that of literature (Zh. Org. Khim., 1977, 13 (12), 2573).₂CO₃And 225 ° C., to give compound (6b) as the main product. The yield of compound (6b) was 71.2%. The presence of compound (6a) was also observed in the product.

[Example 5] Production example of compound (7b) by reduction step
A reduction reaction was performed using the compound (6b) obtained by repeating the reactions of Examples 1 to 4.
A catalyst (100 mL) shown in Table 1 was packed in a reaction tube (1/2 inch in diameter, 1 m in length) made of Inconel 600, and this was externally heated and maintained at 120 ° C., and 0.2 mol / mol of compound (6b) was added. h and at the same time, hydrogen was introduced at a flow rate of 1.0 mol / h to carry out the reaction. As a result of analyzing the outlet gas of the reactor by GC, compound (7b) was obtained with the results shown in Table 1 below. In addition, what carried out 2 mass parts of metal components with respect to 100 mass parts of crushed coconut shell coal was used for all the catalysts.

[Example 6] Production example of compound (3a-1) by esterification step

An esterification process was performed in the same manner as in Example 1 except that 2-tetrahydrofurfuryl alcohol (20 g) in Example 2 was changed to 2-furfuryl alcohol (21 g), and formation of compound (3a-1) was confirmed.
¹⁹F-NMR (282.7 MHz, CDCl₃, CFCl₃) Δ (ppm): -79.9 (1F), -81.3 (3F), -82.1 (3F), -86.4 (1F), -129.5 (2F), -131.5 (1F).
[Example 7] Production example of compound (4b-1) by fluorination step

A fluorination step was performed in the same manner as in Example 2, except that the compound (3b-1) in Example 2 was changed to 5.5 g of the compound (3a-1) obtained in Example 6.
Fluoride after reaction¹⁹When quantified by F-NMR, formation of compound (4b-1) was confirmed, and the yield was 64%.
¹⁹F-NMR (376.0 MHz, CDCl₃, CFCl₃) Δ (ppm): -80.3 (1F), -81.9 (3F), -82.1 (3F), -83.5 to -84.8 (2F), -85.5 to -88 0.0 (3F), -126.5 (1F), -127.4 (1F), -128.1 (1F), -130.2 (2F), -130.4 (1F), -132.2 (1F), -135.8 (1F).
[Example 8] Production example of compound (5a-2) by ester decomposition step

The reaction was carried out in the same manner as in the ester decomposition step of Example 3 except that KOH in Example 3 was changed to NaOH, to obtain a compound (5a-2).
[Example 9] Production example of compound (6a)

Compound (5a-1) in Example 4 was changed to compound (5a-2) obtained in Example 8,₂CO₃To Na₂CO₃The reaction was carried out in the same manner as in Example 4 except that the compound (6a) was obtained as a main component. The yield of compound (6a) was 61.0%. Further, formation of compound (6b) was also observed in the product.
[Example 10] Production example of compound (7a) by reduction step
The compound (6a) obtained by repeating the reactions of Examples 6 to 9 was used in the presence of the compound (6b) in the presence of the catalyst shown in Table 2, and the reduction step was carried out in the same manner as in Example 5 to give the compound (7a) ) Got. The results of analyzing the outlet gas of the reactor by GC are shown in Table 2 below. The presence of compound (7b) was also found in the outlet gas.

[Example 11] Evaluation example as dry etching agent
(Example 11-1) A silicon wafer having a diameter of 150 mm with a silicon oxide film formed on a surface thereof was set in a parallel plate type plasma etching apparatus, the system was evacuated, and then distilled from the product of Example 4. The compound (6b) was gasified and introduced at 50 ml / min (gas temperature 20 ° C.). The pressure in the system was set to 39.9 Pa (absolute pressure), and the plasma density was 10⁹cm^-3Was irradiated for 60 seconds to perform an etching experiment. The etching rate was measured before and after etching at any three points of the film pressure on the wafer. The average of the three points of the etching rate was 2000 Å / min or more, and ○ was used. The result was ○.
(Example 11-2) The same measurement as in Example 11-1 was performed except that the compound (6a) was changed to the compound (6a) obtained in Example 9. The result was ○.
(Example 11-3) Comparative example
The same measurement as in Example 11-1 was performed, except that the compound (6a) was changed to octafluorocyclopentene. The result was x, and the etching reaction did not proceed at all, and a yellow-brown polymer was deposited on the silicon wafer.
[Example 12] Evaluation example as draining dry solvent
A stainless steel mesh (5 cm × 5 cm) was washed in advance and then immersed in water to obtain an article to be washed. The compound (7a) synthesized in Example 10 was used while containing the compound (7b). Ethanol was added to the compound (7b) to prepare a mixed solvent in which the ethanol concentration was adjusted to 5% by mass.
Next, the object to be cleaned was immersed in a mixed solvent at 30 ° C., and drained for one minute using ultrasonic waves. Next, steam cleaning was performed for 30 seconds in the vapor zone of the compound (7a). The dryness after steam washing, the state of the mixed solvent after immersion and drainage, and the state of water floating on the liquid surface of the mixed solvent during immersion and drainage were observed. Was. A: Completely dry without stains. B: Dry but slightly stained. C: Some water remains. D: A large amount of water remains.
The state of the mixed solvent was determined to be A by the following A to D. A: No turbidity, B: Slightly turbid, C: Slightly turbid, D: Strongly turbid.
The state of water floating on the liquid surface was determined to be A by the following A to D. A: floating quickly, B: slightly floating, C: floating slowly, D: floating of water is extremely slow.
[Example 13] Evaluation example as cleaning agent and rinsing agent
Cutting oil (trade name: Daphne Cut AS-40H, manufactured by Idemitsu Kosan Co., Ltd.) was applied to a stainless mesh (5 cm × 5 cm) that had been thoroughly washed in advance, and heated at 100 ° C. for 1 hour to obtain an article to be washed.
The object to be washed was immersed and washed in isododecane (60 ° C.) for 30 seconds, and then the compound (7a) obtained in Example 10 was used while containing the compound (7b). The compound (7a) was immersed and rinsed at 30 ° C. for 30 seconds, and finally subjected to steam cleaning in the vapor zone of the compound (7a) for 30 seconds.
Calculate the residual ratio of the cutting oil from the mass measurement results of the object before and after application of the cutting oil and after washing and drying, and observe the drying state of the object to be washed immediately after steam cleaning. The result was evaluated as A, and was A. A: less than 0.1% by weight, B: 0.1% by weight or more and less than 0.5% by weight, C: 0.5% by weight or more and less than 2% by weight, D: 2% by weight or more. The dried state was evaluated according to the following criteria, and the result was A. A: Immediately dried, B: Slowly dried, C: Partially dried, D: Could not be dried.
<Industrial applicability>
The present invention provides a method for producing a fluorinated cyclic ether in a yield that is a method suitable for industrial practice and economically advantageous in a high yield. The fluorinated cyclic ether of the present invention is a compound useful as a functional agent such as a draining dry solvent, a dry etching agent, or a cleaning agent. Further, according to the present invention, there is provided a novel compound useful as an intermediate of a fluorinated cyclic ether.

Claims (12)

A compound represented by the following formula (5) is thermally decomposed to form at least one fluorinated unsaturated cyclic ether selected from a compound represented by the following formula (6a) and a compound represented by the following formula (6b): A method for producing a fluorinated unsaturated cyclic ether, characterized by being obtained.
However, ^AF represents a perfluorotetrahydrofuranyl group. X represents a fluorine atom or -O ^- M ⁺ (however, M ⁺ represents a counter ion).
^AF COX (5)

The method according to claim 1, wherein the compound represented by the formula (5) is a compound represented by the following formula (5a).

A compound represented by the following formula (5f) in which X in the compound represented by the formula (5) is a fluorine atom, is a compound represented by the following formula (1) and a compound represented by the following formula (2). Reacting to a compound represented by the following formula (3), and fluorinating the compound represented by the formula (3) to a compound represented by the following formula (4), and represented by the formula (4) The method according to claim 1, wherein the compound is obtained by subjecting an ester bond of the compound to a decomposition reaction.
However, ^AF has the same meaning as described above. ^RC represents a monovalent organic group. R ^CF represents a monovalent organic group identical to ^{R C,} or a monovalent organic ^{group R C} is fluorinated. X ¹ represents a halogen atom. A represents a group represented by a formula selected from the following formulas (1a), (1b), (1c), and (1d), or one or more hydrogen atoms in the selected formula. It shows the group represented by the formula substituted by a fluorine atom.
ACH ₂ OH (1)
^RC COX ¹ (2)
ACH ₂ OCOR ^C (3)
A ^F CF ₂ OCOR ^CF (4)
A ^F COF (5f)

The compound represented by the formula (1) is a compound represented by the following formula (1), the compound represented by the formula (3) is a compound represented by the following formula (3), and the compound represented by the formula (4) The production method according to claim 3, wherein ^AF in the compound represented by the formula is a 2-perfluorotetrahydrofuranyl group, and the compound represented by the formula (5f) is a compound represented by the following formula (5a).
Here, ^RC has the same meaning as described above. A ¹ is a group represented by a formula selected from the following formulas (1a-1), (1b-1), (1c-1), and (1d-1), or a selected formula thereof A group represented by the formula in which one or more of the hydrogen atoms in the formula is replaced with a fluorine atom.
A ¹ CH ₂ OH (1)
A ¹ CH ₂ OCOR ^C (3)

A compound represented by the formula (3) is converted to a compound represented by the formula (5) and a compound represented by the following formula (2a) from a reaction product obtained by subjecting an ester bond of the compound represented by the formula (4) to a decomposition reaction. The method according to claim 3, wherein the compound is a compound obtained by obtaining a compound represented by the formula (2a) and reacting the compound represented by the formula (2a) with a compound represented by the formula (1).
Here, R ^CF has the same meaning as described above.
R ^CF COF (2a) The production method according to claim 3, wherein the fluorination is carried out by reacting with fluorine in a liquid phase. A compound represented by the following formula (5) is thermally decomposed to obtain one or more compounds selected from a compound represented by the following formula (6a) and a compound represented by the following formula (6b). The compound represented by the formula (6a) was reduced by performing a reduction reaction of the one or more compounds, and the compound represented by the following formula (7a) and the compound represented by the formula (6b) were reduced. A method for producing a fluorinated saturated cyclic ether, comprising obtaining one or more fluorinated saturated cyclic ethers selected from the compounds represented by the formula (7b).
However, A ^F and X each have the same meaning as described above.
^AF COX (5)

The method according to claim 7, wherein the compound represented by the formula (5) is a compound represented by the following formula (5a).

Any compound represented by the following formula.

Here, R ^C1 and R ^CF1 are each a perfluoroalkyl group, a perfluoro (partial chloroalkyl) group, a perfluoro (etheric oxygen atom-containing alkyl) group, a perfluoro (partial chloro (etheric oxygen atom-containing alkyl)) group, or a perfluoroalkyl group. Indicates a tetrahydrofuranyl group. One or more fluorinated unsaturated cyclic ethers selected from the compound represented by the following formula (6a) and the compound represented by the following formula (6b), or the compound represented by the following formula (7a) and the following formula A functional agent comprising one or more fluorinated saturated cyclic ethers selected from the compounds represented by (7b).

A functional agent containing a compound represented by the following formula (7a).

The functional agent according to claim 10, which is a draining dry solvent, a dry etching agent, or a cleaning agent.