JP4456289B2 - Method for producing primary phosphine - Google Patents

Description

（式中、Ｒ¹は炭素数３〜８の直鎖状又は分岐状のアルキル基、シクロアルキル基、ベンジル基又はアリル基を示す。）
【００１６】
で表される臭化アルキルを、触媒としてテトラアルキルホスホニウムブロマイドを用いて、前記臭化アルキルに対するホスフィンのモル比が１．５倍モル以上で、かつ反応に必要量の触媒を２回以上に分けてまたは添加速度を調整して連続的に反応系内に導入し、６０℃以上で反応を行うことを特徴とする下記一般式（２）
【００１７】
【化６】

（式中、Ｒ¹は前記と同義。）で表される第一級ホスフィンの製造方法である。
前記反応は０．５ＭＰａ以上の加圧下で行なうのが好ましい。
【００１８】
本発明が提供しようとする第二の発明は、ホスフィンとハロゲン化アルキルとをアルカリ水溶液と有機溶媒中で触媒の存在下で反応させて第一級ホスフィンを製造する方法において、反応系に水素および窒素の少なくとも一種をホスフィンと共存させた状態で、ハロゲン化アルキルとして下記一般式（３）
【００１９】
【化７】

（式中、Ｒ²は炭素数１〜１６の直鎖状又は分岐状のアルキル基、シクロアルキル基、ベンジル基又はアリル基を示す。）
【００２０】
で表される臭化アルキルを、触媒としてテトラアルキルホスホニウムブロマイドを用いて、前記臭化アルキルに対するホスフィンのモル比が１．５倍モル以上で、かつ反応に必要量の触媒を２回以上に分けてまたは添加速度を調整して連続的に反応系内に導入し、６０℃以上で反応を行うことを特徴とする下記一般式（４）
【００２１】
【化８】

（式中、Ｒ²は前記と同義。）で表される第一級ホスフィンの製造方法である。
【００２２】
上記の反応系に水素および窒素の少なくとも一種をホスフィンと共存させた状態は、次亜リン酸ソーダの製造の際に副生する水素ガスを含有するホスフィンガスを圧縮した圧縮ホスフィンガスを用いて反応を行なうのが好ましい。
前記圧縮ホスフィンガスを２回以上に分けて反応系内に導入するのが好ましい。
前記反応は０．９８〜３．０ＭＰａの加圧下で行なうのが好ましい。
【００２３】
また、上記の第一および第二の発明において、下記の条件で反応を行なうのが好ましい。
前記触媒のテトラアルキルホスホニウムブロマイドは、トリブチルヘキサデシルホスホニウムブロマイド、テトラブチルホスホニウムブロマイドおよびトリブチルドデシルホスホニウムブロマイドから選ばれる少なくとも一種であるのが好ましい。
前記アルカリ水溶液は水酸化カリウム水溶液であるのが好ましい。
前記アルカリの添加量は臭化アルキル１モルに対して２．５倍モル以上であるのが好ましい。
【００２４】
【発明の実施の形態】
以下、本発明を詳細に説明する。
本発明の第一級ホスフィンの製造方法は、ホスフィンとハロゲン化アルキルとをアルカリ水溶液と有機溶媒中、触媒の存在下に反応させる第一級ホスフィンの製造方法において、反応原料、触媒及び反応条件に特定したことに大きな特徴がある。
【００２５】
即ち、反応原料のハロゲン化アルキルとして前記一般式（１）で表される臭化アルキルを用い、触媒としてテトラアルキルホスホニウムブロマイドを用いる点であり、一方、反応条件としては、ホスフィンと臭化アルキルを特定モル比とし、触媒を反応が完結するまでの間反応系内に存在するように系内に導入し、加温下に反応を行う点である。
また、反応原料のハロゲン化アルキルとして前記一般式（３）で表される臭化アルキルを用い、反応系に水素および窒素の少なくとも一種をホスフィンと共存させた状態で反応を行う点である。
【００２６】
（ホスフィン原料）
原料のホスフィンは、いかなる製法に基づくものであってもよく、例えば、（１）赤リンに水蒸気を反応させることにより得られるホスフィンガス、（２）次亜リン酸ソ−ダの製造に際して副生する粗製ホスフィンを、脱水、脱アルシン、脱低級水素化燐化合物の精製操作をしたホスフィンガス、（３）これをコンプレッサーにより圧縮した圧縮ホスフィンガス（以後、圧縮ホスフィンガスという）及び（４）圧縮ホスフィンガスを液化して水素と分離した液化ホスフィン等が用いられるが、本発明の製造方法においては、液化ホスフィン、圧縮ホスフィンガスを好適に用いることができる。この圧縮ホスフィンガスには、通常５０ｖｏｌ％以上の水素ガスが不純物として混入しているが、本発明においては、この水素ガスを分離除去することなしにホスフィン原料としてそのまま用いることが出来る。
【００２７】
ホスフィンの添加量は、臭化アルキルに対して、通常１．５〜３倍モル、好ましくは１．８〜２．１倍モルである。この理由は、１．５倍モルより小さくなると第一級ホスフィンの反応収率が低くなる傾向があり、一方、３倍モルより大きくなっても反応は進行するが、１バッチ当りの第一級ホスフィンの収量が少なくなり、実用的でない。なお、ホスフィンの反応系への添加は反応の開始時に一度に添加してもよく、また反応の開始と途中に分けて添加してもよい。ここで言うホスフィンの添加量は、反応の開始時は勿論、反応途中に添加したものも含めた総合的な添加量を示すものである。
【００２８】
（臭化アルキル）
もう一方の反応原料には、第一の発明では下記一般式（１）で表される臭化アルキルが用いられる。
【００２９】
【化９】

【００３０】
一般式（１）中、Ｒ¹は、炭素数３〜８の直鎖状又は分岐状のアルキル基、シクロアルキル基、ベンジル基又はアリル基を示す。アルキル基の具体例としては、ｎ−プロピル基、ｉｓｏ−プロピル基、ｎ−ブチル基、ｉｓｏ−ブチル基、ｓｅｃ−ブチル基、ｎ−ヘキシル基、ｉｓｏ−ヘキシル基、ｎ−ヘプチル基、ｉｓｏ−ヘプチル基、ｎ−オクチル基、ｉｓｏ−オクチル基等が挙げられ、これらの中、炭素数３〜６のアルキル基が好ましい。
【００３１】
また、第二の発明では下記一般式（３）で表される臭化アルキルが用いられる。
【００３２】
【化１０】

【００３３】
一般式（３）中、Ｒ²は、炭素数１〜１６の直鎖状又は分岐状のアルキル基、シクロアルキル基、ベンジル基又はアリル基を示す。アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、ｉｓｏ−プロピル基、ｎ−ブチル基、ｉｓｏ−ブチル基、ｓｅｃ−ブチル基、ｎ−ヘキシル基、ｉｓｏ−ヘキシル基、ｎ−ヘプチル基、ｉｓｏ−ヘプチル基、ｎ−オクチル基、ｉｓｏ−オクチル基、ｎ−デシル基、ｉｓｏ−デシル基、ｎ−ドデシル基、ｉｓｏ−ドデシル基、ｎ−テトラデシル基、ｉｓｏ−テトラデシル基、ｎ−ヘキサデシル基、ｉｓｏ−ヘキサデシル基等が挙げられ、これらの中、炭素数１〜８のアルキル基が好ましい。
【００３４】
（触媒）
触媒のテトラアルキルホスホニウムブロマイドとしては、下記一般式（３）
【００３５】
【化１１】

【００３６】
（式中、Ｒ³、Ｒ⁴、Ｒ⁵およびＲ⁶は、同種または異種の炭素数１〜１８の直鎖状又は分岐状のアルキル基を示す。）
で表されるホスホニウム塩が用いられる。前記一般式（３）の式中、Ｒ³〜Ｒ⁶のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、オクチル基、ヘキサデシル基等の炭素数１〜１８のアルキル基であり、具体的な化合物としては、例えば、トリブチルメチルホスホニウムブロマイド、テトラブチルホスホニウムブロマイド、トリオクチルメチルホスホニウムブロマイド、トリオクチルエチルホスホニウムブロマイド、トリブチルドデシルホスホニウムブロマイド、トリブチルヘキサデシルホスホニウムブロマイド、トリオクチルエチルホスホニウムブロマイド等のホスホニウム塩等が挙げられ、これらは一種または二種以上で用いることができる。
【００３７】
これらのホスホニウム塩の中、トリブチルドデシルホスホニウムブロマイド、テトラブチルホスホニウムブロマイド、トリブチルヘキサデシルホスホニウムブロマイドが特に好ましい。
【００３８】
テトラアルキルホスホニウムブロマイドの添加量は、ハロゲン化アルキルに対して通常０．１〜３モル％、好ましくは１〜２モル％である。なお、本発明において、この触媒のテトラアルキルホスホニウムブロマイドの反応系内への導入は、後述するように、反応に必要量の触媒を２回以上に分けてまたは添加速度を調整して連続的に反応系内に導入し、反応が完結するまで必要量の該触媒が反応系内に存在するように行うことが重要である。
【００３９】
アルカリ水溶液としては、水酸化ナトリウム、水酸化カリウム等の水酸化アルカリ水溶液が挙げられ、これらの中、水酸化カリウムが好ましい。これらは、通常４０〜７０重量％、好ましくは５０〜６０重量％の水溶液として用いられ、アルカリ水溶液の添加量は、臭化アルキルに対して通常２．５倍モル以上、好ましくは２．５〜４倍モル、さらに好ましくは３倍モルである。
【００４０】
有機溶媒としては、例えば、ベンゼン、トルエン、キシレン、メシチレン、クロロベンゼン、ジクロロベンゼン、アニソール、ニトロベンゼン、ニトロトルエン等の芳香族類：ペンタン、ヘキサン、ヘプタン、オクタン、ノナン、リグロイン、シクロヘキサン等の脂肪族炭化水素類：ジエチルエーテル、イソプロピルエーテル、エチレングリコールジメチルエーテル、ジエチレングリコールジメチルエーテル、ベンジルエーテル、ジオキサン、テトラヒドロフラン等のエーテル系溶媒：メタノール、エタノール、２−プロパノール、２−ブタノール、２−メチル−２−プロパノール等のアルコール：Ｎ，Ｎ−ジメチルアセトアミド、ヘキサメチルホスホルアミド、スルホラン等の有機極性溶媒等が挙げられ、これらは一種または二種以上で用いることができる。これらの有機溶媒の中でトルエンが特に好ましい。
【００４１】
＜反応条件＞
本発明の製造方法は、予め前記した臭化アルキル、アルカリ水溶液及び有機溶媒を反応容器に仕込み、次いで、ホスフィンガスを仕込んで、６０℃以上に加温した後、触媒のテトラアルキルホスホニウムブロマイドを反応系内に添加し加圧下に反応を行う。
【００４２】
この反応はアルカリ水溶液及び有機溶媒中で行われ、ホスフィンはアルカリの存在によりＨ⁺ が除去され、ＰＨ₂ ^-となるが、この過程は触媒のテトラアルキルホスホニウムブロマイドの存在により促進され、ＰＨ₂ ^-は（Ｒ¹）⁺−Ｂｒ^-または（Ｒ²）⁺−Ｂｒ^-（臭化アルキル）と反応して、目的生成物であるＲ¹ＰＨ₂またはＲ²ＰＨ₂の第一級ホスフィンが得られる。
【００４３】
なお、本発明の製造方法において、上記の触媒の添加は、反応完結まで反応に必要な量の触媒が存在するように、一度に添加せず、２回以上にわたってまたは連続的に添加することが重要な要件となる。この理由は、触媒のテトラアルキルホスホニウムブロマイドは、反応系内のアルカリ源と反応して分解し、この分解反応は、目的とする第一級ホスフィンの合成反応と競争的に進行し、反応中に触媒濃度が低下するため目的生成物である第一級ホスフィンの収率が低下するからである。従って、触媒のテトラアルキルホスホニウムブロマイドの反応系内への添加は、除々に時間をかけて添加するか、もしくは何回かに分けて多段式に添加することが好ましく、いずれの方法をとるかは、装置等の都合により適宜選択すればよいが、多段式に添加する方が触媒量を制御しやすいことから工業的に有利となる。
【００４４】
より具体的には、触媒のテトラアルキルホスホニウムブロマイドを２回以上にわたって添加する場合には、一回目の添加量はハロゲン化アルキルに対して０．０５〜２．０モル％、好ましくは０．５〜１．０モル％とし、一回目の添加終了後２〜３時間を目安として、二回目以降の添加を行えばよい。本発明においてこの２回以上に分けて添加するとは、通常二回に分けて添加することが好ましい。二回目の添加量は、ハロゲン化アルキルに対して０．０５〜１．０モル％、好ましくは０．５〜１．０モル％とすることが好ましい。
【００４５】
一方、該テトラアルキルホスホニウムブロマイドの添加速度を調整して徐々に反応系に添加する場合、５〜６時間を目安として徐々に導入すればよい。
【００４６】
反応温度は、通常６０℃以上、好ましくは７０〜１００℃である。反応温度はアルキルブロマイドとホスフィンとの反応性により適宜選択するが、一般的に低級アルキルブロマイド程反応性が高く、反応温度が低くても反応が進行する。ただし、反応温度が６０℃より低くなると、反応が進行しにくくなる傾向があり、目的生成物である第一級ホスフィンの収率が低下するので好ましくない。また、反応温度が１００℃より大きくなると反応場である有機溶媒に溶解するホスフィンガスの量が減少し効率が悪くなり、また、反応系内の圧力がいたずらに高くなりすぎ工業的に不利となるため好ましくない。
【００４７】
反応圧力は、反応原料として用いるホスフィンガスの種類により異なり、液化ホスフィンを用いた場合には、通常０．５ＭＰａ以上、好ましくは０．５〜１．５ＭＰａであり、反応系に水素および窒素の少なくとも一種をホスフィンと共存させた状態で反応を行なう場合は、０．９８〜３．０ＭＰａであり、また圧縮ホスフィンガスを用いる場合には、通常０．９８〜３．０ＭＰａで反応は行われる。
反応時間は、通常５時間以上、好ましくは１０〜１５時間である。
【００４８】
本発明において、反応系に水素および窒素の少なくとも一種をホスフィンと共存させた状態で反応を行なう場合は、ホスフィンが４０Ｖｏｌ％以上、好ましくは４０〜９０Ｖｏｌ％、水素および窒素の少なくとも一種が６０Ｖｏｌ％以下、好ましくは１０〜６０Ｖｏｌ％の割合で混合して用いるのが好ましい。
【００４９】
この混合ガスの反応系への添加は、反応の開始時に一度に添加してもよく、また反応の開始時と途中に数回に分けて添加してもよい。なお、ホスフィンの添加量は、反応の開始時は勿論、反応途中に添加したものも含めた総合的な添加量を含めて前述したと同様に臭化アルキルに対して、通常１．５〜３倍モル、好ましくは１．８〜２．１倍モルの範囲であるのが好ましい。
【００５０】
なお、本発明においては、水素ガスをホスフィンガスに対して１〜３倍（体積比）程度含んでいる圧縮ホスフィンガスを用いて反応を行う場合には、水素ガスが有機溶媒にほとんど溶解しないため全量を反応系内に圧入すると反応系内の圧力が通常５０ｋｇ／ｃｍ² 以上の高圧となることから、また反応で消費されたホスフィンガスの補充のために反応を進めながら、何回かに分けて圧縮ホスフィンガスを圧入することが好ましい。
【００５１】
上記の原料のホスフィンガスに水素および窒素の少なくとも一種を共存させた状態で反応を行なうと、上記の精製工程を経たホスフィンガスを用いた場合と同様に反応が進行し、反応中に第二級ホスフィン、第三級ホスフィン化合物の副生がなく、高い収率で目的とする第一級ホスフィンが得られる。
また、圧縮ホスフィンガス（ＰＨ₃：Ｈ₂＝４０：６０（ｖｏｌ％））を用いて反応を行っても、液化ホスフィンを用いた場合と同様の収率が得られ、また生成物も同様に目的とする第一級ホスフィン純度が高いものが得られる。
【００５２】
ホスフィンガスとＨ₂、Ｎ₂等の不活性ガスとの混合ガスを反応に用いると、ホスフィンガスは有機溶媒に溶解し、ハロゲン化アルキルとの反応に消費されるが、不活性ガスはハロゲン化アルキルとの反応に関与しない。混合ガス中のホスフィンガスとハロゲン化アルキルの反応は有機溶媒中で行われ、収率は液化ホスフィンを用いた場合と同等であり、生成物も同様に目的とする第―級ホスフィン純度の高いものである。さらに、反応終了後の残ガスは、ホスフィンガスが反応に消費されるため相対的に未反応ホスフィンガスの濃度が下がることになる。このため、液化ホスフィンガスを反応に用いる場合と比べると、残ガスは猛毒のホスフィンガス濃度の低いものとなり、毒性の点で安全性が向上するという利点を有する。
【００５３】
上記の反応終了後は、反応容器内に残存する未反応のホスフィンガスを、また水素ガスや窒素ガスを共存させて反応を行った場合は未反応のホスフィンガス及び水素ガスや窒素ガスを分離することが好ましい。この場合、反応容器内を窒素ガス等の不活性ガスにより置換し、必要があれば加温還流することにより、溶媒及び第一級ホスフィンを反応容器内に残しながらホスフィンガス及び水素ガスや窒素ガスを系外に排出し、反応液を採取し、分液して製品とすることができる。
かくして、目的とする第一級ホスフィンを選択的かつ高収率で得ることができる。
【００５４】
【実施例】
以下、本発明を実施例により詳細に説明するが本発明はこれらに限定されるものではない。
【００５５】
試験例１
＜触媒分解試験＞
室温下、５６％ＫＯＨ水溶液１０５．３ｇ（１．０５ｍｏｌ）、トルエン１００ｍｌ、１−ブロモブタン４７．９ｇ（０．３５ｍｏｌ）を３００ｍｌの４つ口フラスコに仕込み、攪拌機を用いて４００ｒｐｍで攪拌した。ここに、トリ−ｎ−ブチルヘキサデシルホスホニウムブロマイド２．４１ｇ（４．７２ｍｍｏｌ）を仕込み、１０分後、反応液中のトルエン相をサンプリングし³¹Ｐ ＮＭＲ分析をおこなった。その後、攪拌しながら４０℃又は８０℃に昇温し、１時間後に再びトルエン相を採取し³¹Ｐ ＮＭＲ分析をおこなった。その結果を表１に示した。
【００５６】
表１から、４０℃、８０℃いずれにおいてもアルカリと接触後１時間後には、ホスホニウム塩であるトリｎ−ブチルヘキサデシルホスホニウムブロマイドが分解し、トリｎ−ブチルホスフィンオキサイドになっていることがわかる。
【００５７】
なお、アルカリと接触後１時間後の水相の³¹Ｐ ＮＭＲ分析を行ったところ、トリｎ−ブチルヘキサデシルホスホニウムブロマイド、トリｎ−ブチルホスフィンオキサイドいずれもトルエン相のものに比べてピークが小さく、水相にはほとんど溶解していないことがわかった。以上の結果より、トリ−ｎ−ブチルヘキサデシルホスホニウムブロマイドは、アルカリと接触後１時間で、ほぼ全量が分解してしまっていることが示唆される。
【００５８】
【表１】

【００５９】
（注）
ＰＸ−４１６Ｂ：トリｎ−ブチルヘキサデシルホスホニウムブロマイド
ＰＯ−４：トリｎ−ブチルホスフィンオキサイド
【００６０】
実施例１
室温下、５６％ＫＯＨ水溶液１０５．４ｇ（１．０５ｍｏｌ）、トルエン７０ｍｌ、１−ブロモブタン４８．０ｇ（０．３５ｍｏｌ）を１Ｌオートクレーブに仕込み、充分に窒素置換した後、攪拌機を用いて４００ｒｐｍで攪拌した。ここに、液化ホスフィンガスを２３．８ｇ（０．７ｍｏｌ）仕込んだ。その後、８０℃に昇温した。温度が８０℃に達した際の内圧は１．５ＭＰａであった。
【００６１】
次いで、トルエン３０ｍｌに溶解させたトリ−ｎ−ブチルヘキサデシルホスホニウムブロマイド２．４ｇ（４．７２ｍｍｏｌ）溶液の５０重量％を１０分かけて圧入した。圧入終了後の内圧は１．３５ＭＰａであった。８０℃で２時間熟成した後、残り５０重量％のテトラ−ｎ−ブチルホスホニウムブロマイドのトルエン溶液を再び１０分かけて圧入した。圧入終了後、内圧は０．９１ＭＰａを示していた。このままの温度で一晩保持した。反応終了後の内圧は０．８５ＭＰａを示していた。
【００６２】
室温まで冷却し、水５０ｇを圧入してしばらく攪拌し副生するＫＢｒを溶解させた後、未反応ホスフィンガスを常圧となるまで放出した。次いで窒素ガスを１．５ＭＰａ程度に加圧してオートクレーブに加え、常圧まで放出する操作を数回繰り返し充分に窒素置換した。その後、再び窒素ガスによりオートクレーブ内を０．３ＭＰａ程度に加圧して分液し水相を廃棄した。更に水１００ｍｌを加えて水洗をおこない、静置後水相を分液して廃棄することにより目的とするモノノルマルブチルホスフィンのトルエン溶液を得た。
なお、生成物の分析はガスクロマトグラフ法（ＧＣ分析）により行った。
【００６３】
実施例２
室温下、５６％ＫＯＨ水溶液１０５．４ｇ（１．０５ｍｏｌ）、トルエン７０ｍｌ、１−ブロモブタン４８．０ｇ（０．３５ｍｏｌ）を仕込んだ１Ｌオートクレーブを充分に窒素置換し、攪拌機により４００ｒｐｍで攪拌した。ここに、液化ホスフィンガス２３．８ｇ（０．７ｍｏｌ）を仕込んだ。次いで、８０℃に昇温した。温度が８０℃に達した際の内圧は１．５ＭＰａを示した。
【００６４】
次いで、トルエン３０ｍｌに溶解させたテトラ−ｎ−ブチルホスホニウムブロマイド１．３ｇ（３．８ｍｍｏｌ）溶液を２０分かけて圧入した。圧入終了後の内圧は１．０ＭＰａであった。８０℃で約２時間熟成した後、トルエン３０ｍｌに溶解させたテトラ−ｎ−ブチルホスホニウムブロマイド１．２ｇ（３．５ｍｍｏｌ）を再び２０分かけて圧入した。圧入終了後、内圧は０．６ＭＰａを示していた。このままの温度で一晩保持した。反応終了後の内圧は０．５７ＭＰａを示していた。
【００６５】
室温まで冷却し、水５０ｇを圧入してしばらく攪拌し副生するＫＢｒを溶解させた後、未反応ホスフィンガスを常圧になるまで放出した。次いで窒素ガスを１．５ＭＰａ程度に加圧してオートクレーブに加え、常圧まで放出する操作を数回繰り返し充分に窒素置換した。その後、再び窒素ガスによりオートクレーブ内を０．３ＭＰａ程度に加圧して分液し水相を廃棄した。更に水１００ｍｌを加えて水洗をおこない、静置後水相を分液して廃棄することにより目的とするモノノルマルブチルホスフィンのトルエン溶液を得た。
なお、生成物の分析はガスクロマトグラフ法により行った。
【００６６】
実施例３
室温下、５６％ＫＯＨ水溶液１０５．４ｇ（１．０５ｍｏｌ）、トルエン１００ｍｌ、１−ブロモブタン４８．０ｇ（０．３５ｍｏｌ）を仕込んだ１Ｌオートクレーブを充分に窒素置換し、攪拌機により４００ｒｐｍで攪拌した。ここに、液状化ホスフィンガス２３．８ｇ（０．７ｍｏｌ）を仕込んだ。次いで、６０℃に昇温した。温度が６０℃に達した際の内圧は１．２５ＭＰａを示した。
【００６７】
次いで、トルエン３０ｍｌに溶解させたトリ−ｎ−ブチルドデシルホスホニウムブロマイド１．６ｇ（３．５ｍｍｏｌ）溶液を１５分かけて圧入した。圧入終了後の内圧は１．１５ＭＰａであった。６０℃で約２時間熟成した後、トルエン３０ｍｌに溶解させたトリ−ｎ−ブチルドデシルホスホニウムブロマイド１．６ｇ（３．５ｍｍｏｌ）を再び１５分かけて圧入した。圧入終了後、内圧は０．９ＭＰａを示していた。このままの温度で一晩保持した。反応終了後の内圧は０．７ＭＰａを示していた。
【００６８】
室温まで冷却し、水５０ｇを圧入してしばらく攪拌し副生するＫＢｒを溶解させた後、未反応ホスフィンガスを常圧になるまで放出した。次いで、窒素ガスを１．５ＭＰａ程度に加圧してオートクレーブに加え、常圧まで放出する操作を数回繰り返し充分に窒素置換した。その後、再び窒素ガスによりオートクレーブ内を０．３ＭＰａ程度に加圧して分液し水相を廃棄した。更に水１００ｍｌを加えて水洗をおこない、静置後水相を分液して廃棄することにより目的とするモノノルマルブチルホスフィンのトルエン溶液を得た。
なお、生成物の分析はガスクロマトグラフ法により行った。
【００６９】
比較例１
室温下、５６％ＫＯＨ水溶液９．９６ｇ（９９．４ｍｍｏｌ）、トルエン１９ｍｌ、１−ブロモブタン５．２９ｇ（３８．６ｍｍｏｌ）、トリ−ｎ−ブチルヘキサデシルホスホニウムブロマイド０．２２ｇ（０．４３ｍｍｏｌ）を仕込んだオートクレーブを充分に窒素置換し、攪拌機により３００ｒｐｍで攪拌した。ここに、ホスフィンガスを２．２７ｇ（６６．７ｍｍｏｌ）仕込んだ。その後、６０℃への昇温を行った。温度が６０℃に達した際の内圧は０．６５ＭＰａを示した。このままの温度で一晩保持した。反応終了後の内圧は０．６ＭＰａを示していた。
【００７０】
室温まで冷却し、水１０ｇを圧入してしばらく攪拌し副生するＫＢｒを溶解させた後、未反応ホスフィンガスを常圧になるまで放出した。次いで窒素ガスを１．５ＭＰａ程度に加圧してオートクレーブに加え、常圧まで放出する操作を数回繰り返し充分に窒素置換した。その後、再び窒素ガスによりオートクレーブ内を０．３ＭＰａ程度に加圧して分液し水相を廃棄した。更に水１００ｍｌを加えて水洗をおこない、静置後水相を分液して廃棄することにより目的とするモノノルマルブチルホスフィンのトルエン溶液を得た。
なお、生成物の分析はガスクロマトグラフ法により行った。その結果を表３に示した。
【００７１】
比較例２
反応温度を４０℃とした以外は、比較例１と同様な操作により反応を行った。
なお、生成物の分析はガスクロマトグラフ法により行った。
【００７２】
比較例３
１−ブロモブタンに代えて、１−クロロブタンを用いた以外は実施例１と同様な操作により反応を行った。
なお、生成物の分析はガスクロマトグラフ法により行った。
【００７３】
比較例４
実施例１の１−ブロモブタンに対して、５６％ＫＯＨの使用量を３倍モルに代えて、２倍モルとした以外は実施例１と同様な操作で反応を行った。
【００７４】
比較例５
実施例１の１−ブロモブタンに代えて、１−ブロモヘキサデカンを用いた以外は実施例１と同様な操作で反応を行った。
【００７５】
以上の実施例１〜３および比較例１〜６の実験条件を表２に、その結果を表３に示す。
【００７６】
【表２】

【００７７】
（注）
ＲＸ：ハロゲン化アルキル
ＰＨ₃ ：ホスフィン
ＢｕＢｒ：１−ブロモブタン
ＢｕＣｌ：１−クロロブタン
Ｃ₁₆Ｈ₃₃Ｂｒ：１−ブロモヘキサデカン
４１６Ｂ：トリｎ−ブチルヘキサデシルホスホニウムブロマイド
４Ｂ；テトラｎ−ブチルホスホニウムブロマイド
４１２Ｂ：トリｎ−ブチルドデシルホスホニウムブロマイド
【００７８】
【表３】

【００７９】
（注）
ＲＸ：ハロゲン化アルキル
ＢｕＰＨ₂ ：モノノルマルブチルホスフィン
ＢｕＢｒ：１−ブロモブタン
ＢｕＣｌ：１−クロロブタン
Ｃ₁₆Ｈ₃₃Ｂｒ：１−ブロモヘキサデカン
【００８０】
実施例４
室温下、５６％の水酸化カリウム水溶液１０５．４ｇ（１．０５ｍｏｌ）、トルエン７０ｍｌ、１−ブロモブタン４８．０ｇ（０．３５ｍｏｌ）を仕込んだ１Ｌオートクレーブを充分に窒素置換し、攪拌機により４００ｒｐｍで攪拌した。次亜リン酸ソーダ製造工程から副生するホスフィン圧縮ガス（ホスフィンガス４３．４ｖｏｌ％、水素ガス５６．６ｖｏｌ％）を１１．０ｇ（ホスフィン０．３００ｍｏｌ、水素０．３９２ｍｏｌ）仕込んだ。その後、８０℃に昇温した。その際の内圧は２．２ＭＰａであった。
【００８１】
次いで、トルエン３０ｍｌに溶解させたトリ−ｎ−ブチルヘキサデシルホスホニウムブロマイド２．４ｇ（４．７２ｍｍｏｌ）溶液を最初にまず３４重量％を１５分間かけて圧入した。圧入終了後の内圧は２．２ＭＰａであった。このままの温度で２時間保持して内圧が２．１ＭＰａまで下がったところで未反応の圧縮ガスを常圧まで放出して、再び次亜リン酸ソーダ製造工程から副生するホスフィン圧縮ガスを１０．０ｇ（ホスフィン０．２７３ｍｏｌ、水素０．３５６ｍｏｌ）仕込んだ。この際の内圧は２．４ＭＰａであった。更に、ここに３３重量％のトリ−ｎ−ブチルヘキサデシルホスホニウムブロマイドのトルエン溶液を７分間かけて圧入して仕込んだ。この際の反応系内の内圧は２．４ＭＰａであった。再び、このままの温度で１時間４０分保持して内圧が２．１ＭＰａまで下がったところで未反応の圧縮ガスを常圧まで放出して、再び次亜リン酸ソーダ製造工程から副生するホスフィン圧縮ガスを６．０ｇ（ホスフィン０．１６３ｍｏｌ、水素０．２１４ｍｏｌ）仕込んだ。この際の内圧は１．８ＭＰａであった。更に、ここに残りの３３重量％のトリ−ｎ−ブチルヘキサデシルホスホニウムブロマイドのトルエン溶液を８分間かけて圧入して仕込んだ。この際の反応系内の内圧は１．８ＭＰａであった。このまま８０℃の温度で一晩保持して、反応を終了した。この際の内圧は１．７ＭＰａであった。
【００８２】
次いで、室温まで冷却した後、水１００ｇを圧入してしばらく攪拌した後、未反応ホスフィンガスを常圧になるまで放出した。次いで、窒素ガスを１．５ＭＰａ程度に加圧してオートクレーブに加え、常圧まで放出する操作を数回繰り返し充分に窒素置換した。
【００８３】
その後、再び窒素ガスによりオートクレーブ内を０．３ＭＰａ程度に加圧して分液し水相を廃棄した。更に水１００ｍｌを加えて水洗をおこない、静置後水相を分液して廃棄することにより目的とするモノノルマルブチルホスフィンのトルエン溶液を得た。
なお、生成物の分析はガスクロマトグラフィー法により行った。
【００８４】
実施例５
触媒のトリ−ｎ−ブチルヘキサデシルホスホニウムブロマイドの添加温度を１００℃とした以外は、実施例４と同様な操作で反応を行った。
なお、生成物の分析はガスクロマトグラフ法により行った。
【００８５】
実施例６
実施例２の液化ホスフィンガス２３．８ｇ（０．７０ｍｏｌ）の代りに、液化ホスフィンガス２３．８ｇ（０．７０ｍｏｌ）を仕込み、次いで水素０．６ｇ（０．３０ｍｏｌ）を仕込んだ他は、実施例２と同様の操作により反応を行った。
【００８６】
実施例７
実施例２の液化ホスフインガス２３．８ｇ（０．７０ｍｏｌ）の代りに、液化ホスフィンガス２３．８ｇ（０．７０ｍｏ１）を仕込み、次いで窒素８．４ｇ（０．３０ｍｏｌ）を仕込んだ他は、実施例２と同様の繰作により反応を行った。
【００８７】
実施例８
実施例２の液化ホスフインガス２３．８ｇ（０．７０ｍｏｌ）の代りに、液化ホスフィンガス２３．８ｇ（０．７０ｍｏｌ）を仕込み、次いで水素０．４ｇ（０．２０ｍｏｌ）及び窒素２．８ｇ（０．１０ｍｏ１）を仕込んだ他は、実施例２と同様の操作により反応を行った。
【００８８】
実施例９
実施例２の液化ホスフインガス２３．８ｇ（０．７０ｍｏｌ）の代りに、液化ホスフィンガス２３．８ｇ（０．７０ｍｏｌ）を仕込み、次いで水素０．６ｇ（０．３０ｍｏｌ）を仕込み、１−ブロモブタン４８．０ｇ（０．３５ｍｏｌ）の代わりに１−ブロモデカン７７．４１ｇ（０．３５ｍｏｌ）を用い、温度８０℃の代わりに１００℃で行った他は、実施例２と同様の操作により反応を行った。
【００８９】
以上の実施例４〜９の反応条件を表４に、その結果を表５に示す。
【００９０】
【表４】

【００９１】
（注）
ＲＸ：ハロゲン化アルキル
ＢｕＢｒ：１−ブロモブタン
Ｃ₁₀Ｈ₂₁Ｂｒ：１−ブロモデカン
【００９２】
【表５】

【００９３】
（注）
ＲＸ：ハロゲン化アルキル
ＲＰＨ₂：第一級ホスフィン
【００９４】
実施例１０
ＫＯＨ水溶液に代えて、ＮａＯＨ水溶液を用いた以外は実施例１と同様な操作により反応を行った。実施例１より収率が少し低下したが、モノノルマルブチルホスフィンが得られた。
【００９５】
【発明の効果】
上記したとおり、本発明の製造方法によれば、触媒を一度に全量導入したときに比べ、収率良く目的とする第一級ホスフィンを製造することが出来る。
更に反応系に水素および窒素をホスフィンと共存させて用いても副生物がほとんど生成されず目的とする第一級ホスフィンのみを収率よく得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a high-purity primary phosphine useful as a phosphorus raw material used in flame retardants such as fibers and plastics, antistatic agents, and organometallic chemical vapor deposition methods such as epitaxial growth methods.
[0002]
[Prior art]
Primary phosphine compounds are used as flame retardants such as fibers and plastics, resin modifiers, antistatic agents, etc., and in recent years as phosphorus raw materials used in metal organic chemical vapor deposition (MOCVD) methods such as epitaxial growth. Is also used.
[0003]
Since the primary phosphine has two highly reactive hydrogen groups, it can be made into various useful compounds by adding it to a compound having an unsaturated bond and optionally oxidizing it. For example, bifunctional compounds useful for flame retardants can be easily obtained by adding allyl alcohol or acrylic acid, and phosphines having different alkyl chain lengths can be obtained by adding unsaturated alkyl groups. Further, phosphine oxide and phosphonium salt can be obtained. Further, by oxidizing primary phosphine, phosphinic acid and phosphonic acid can be sequentially obtained to obtain various useful functional compounds.
[0004]
Conventionally, as a method for producing a primary phosphine, an attempt was made to synthesize with a radical polymerization catalyst, but a reaction with a radical catalyst produced a mixture of primary to tertiary phosphine, from which a primary phosphine was produced. It is very difficult to isolate phosphine alone, and the yield of primary phosphine obtained is low ["J. Org. Chem.", 26, 5138-5145 (1961)]. .
[0005]
In addition, an acid-catalyzed reaction of phosphine and alkene is known [“J. Org. Chem.”, 24 356-359 (1959), US Pat. No. 2,584,112]. In this method as well, secondary production of secondary phosphine and tertiary phosphine cannot be avoided as in the case of using a radical catalyst.
[0006]
Also, a method of hydrolyzing a halogenated organophosphonium (JP-A-50-116426), a method of reacting phosphine with a halogenated hydrocarbon in the presence of an aqueous alkali metal hydroxide solution and dimethyl sulfoxide under specific conditions. (Japanese Patent Laid-Open No. 01-102091) and the like have also been proposed.
[0007]
Further, JP-A-01-113397 proposes a method for producing a primary phosphine in which a phosphine and an alkyl halide are reacted in the presence of a tetraalkylammonium salt or tetraalkylphosphonium salt catalyst and an alkali hydroxide. Has been.
[0008]
[Problems to be solved by the invention]
However, even if the method described in JP-A-01-113397 is actually applied to a primary phosphine, a primary phosphine compound cannot be obtained in a high yield. That is, in this primary phosphine production method, all of the alkali hydroxide and the tetraalkylphosphonium salt of the catalyst are added simultaneously with the raw material charging. Here, it is generally known that a phosphonium salt reacts with a high concentration of base to cause a decomposition reaction. Since the decomposition reaction of the phosphonium salt itself of this catalyst proceeds competitively with the synthesis reaction of the primary phosphine, the concentration of the catalyst acting on the target primary phosphine synthesis reaction is reduced, There is a problem that the yield is low.
[0009]
As the phosphine used in the above primary phosphine production method, purified high purity phosphine is used.
On the other hand, as a method for industrially producing phosphine gas, phosphine gas is generated by reaction of yellow phosphorus and alkali. The gas generated here is a mixture of hydrogen gas and phosphine gas, and the hydrogen gas is by-produced about 1 to 3 times (volume ratio) with respect to the phosphine gas. As a method for separating the phosphine gas, a method of compressing and cooling, liquefying the phosphine and separating it from hydrogen, and the like are employed. However, a multi-step process is required. For this reason, if phosphine gas can be used as a reaction raw material in a state in which hydrogen gas is mixed, it is extremely advantageous industrially.
[0010]
In view of the above problems, the present inventors have conducted extensive research on a method for producing primary phosphine. As a result, phosphine and alkyl halide are reacted in an aqueous alkali solution and an organic solvent in the presence of a tetraalkylphosphonium salt catalyst. In the method for producing primary phosphine, a specific alkyl halide is used, a specific phosphonium salt is used as a catalyst, the molar ratio of the raw material phosphine to the alkyl halide is in a specific range, and the It was discovered that by introducing the catalyst into the reaction system so that an effective amount of catalyst is present until the reaction is completed, the desired primary phosphine can be easily obtained in a high yield. It came to complete.
[0011]
Furthermore, in the production method of primary phosphine described above, when a reaction is carried out with an alkyl halide using purified phosphine gas having a high purity as a raw material, a high yield reaction proceeds, but an unreacted gas after completion of the reaction. Is a high-purity phosphine gas, and sufficient care must be taken in handling the exhaust gas. On the other hand, when the reaction is carried out in the state where at least one of hydrogen and nitrogen coexists with the phosphine gas of the raw material, the reaction proceeds in the same manner as in the case of using the phosphine gas that has undergone the above purification process, and a highly toxic phosphine. Since the concentration can be reduced, there is safety, and a compressed phosphine gas obtained by compressing a phosphine gas containing hydrogen gas as a by-product during the production of sodium hypophosphite as an impurity can be used. In addition, it was found that the desired primary phosphine can be easily obtained in high yield without secondary production of secondary phosphine and tertiary phosphine compound during the reaction.
[0012]
That is, the first invention of the present invention uses a specific alkyl halide and a specific catalyst, and is introduced in two or more times or continuously without adding the catalyst at a time under specific conditions. Accordingly, it is an object to selectively obtain primary phosphine with high yield.
[0013]
In addition, the second invention of the present invention is an industrially advantageous first invention in which the desired primary phosphine can be obtained in a high yield by allowing at least one of hydrogen and nitrogen to coexist in the phosphine gas of the raw material. It aims at providing the manufacturing method of primary phosphine.
[0014]
[Means for Solving the Problems]
The first invention to be provided by the present invention is a method for producing a primary phosphine by reacting a phosphine and an alkyl halide in an alkaline aqueous solution and an organic solvent in the presence of a catalyst. General formula (1)
[0015]
[Chemical formula 5]

(Wherein R¹Represents a linear or branched alkyl group, cycloalkyl group, benzyl group or allyl group having 3 to 8 carbon atoms. )
[0016]
Using tetraalkylphosphonium bromide as a catalyst, the molar ratio of phosphine to alkyl bromide is 1.5 times mol or more, and the catalyst required for the reaction is divided into two or more times. Or continuously added into the reaction system with the addition rate adjusted, and the reaction is carried out at 60 ° C. or higher.
[0017]
[Chemical 6]

(Wherein R¹Is as defined above. It is a manufacturing method of the primary phosphine represented by this.
The reaction is preferably performed under a pressure of 0.5 MPa or more.
[0018]
A second invention to be provided by the present invention is a method for producing a primary phosphine by reacting a phosphine and an alkyl halide in an alkaline aqueous solution and an organic solvent in the presence of a catalyst. In the state where at least one kind of nitrogen coexists with phosphine, the following general formula (3)
[0019]
[Chemical 7]

(Wherein R²Represents a linear or branched alkyl group, cycloalkyl group, benzyl group or allyl group having 1 to 16 carbon atoms. )
[0020]
Using tetraalkylphosphonium bromide as a catalyst, the molar ratio of phosphine to alkyl bromide is 1.5 times mol or more, and the catalyst required for the reaction is divided into two or more times. Or continuously added into the reaction system after adjusting the addition rate, and the reaction is carried out at 60 ° C. or higher.
[0021]
[Chemical 8]

(Wherein R²Is as defined above. It is a manufacturing method of the primary phosphine represented by this.
[0022]
The reaction system in which at least one of hydrogen and nitrogen coexists with phosphine is obtained by using a compressed phosphine gas obtained by compressing a phosphine gas containing hydrogen gas by-produced during the production of sodium hypophosphite. Is preferably performed.
The compressed phosphine gas is preferably introduced into the reaction system in two or more times.
The reaction is preferably performed under a pressure of 0.98 to 3.0 MPa.
[0023]
In the first and second inventions described above, the reaction is preferably performed under the following conditions.
The catalyst tetraalkylphosphonium bromide is preferably at least one selected from tributylhexadecylphosphonium bromide, tetrabutylphosphonium bromide and tributyldodecylphosphonium bromide.
The alkaline aqueous solution is preferably a potassium hydroxide aqueous solution.
The addition amount of the alkali is preferably 2.5 times mol or more per 1 mol of alkyl bromide.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The primary phosphine production method of the present invention is a primary phosphine production method in which a phosphine and an alkyl halide are reacted in an alkaline aqueous solution and an organic solvent in the presence of a catalyst. There is a big feature in the identification.
[0025]
That is, the alkyl bromide represented by the general formula (1) is used as the alkyl halide of the reaction raw material, and the tetraalkylphosphonium bromide is used as the catalyst. On the other hand, the reaction conditions include phosphine and alkyl bromide. The specific molar ratio is that the catalyst is introduced into the reaction system so as to exist in the reaction system until the reaction is completed, and the reaction is carried out under heating.
In addition, the alkyl bromide represented by the general formula (3) is used as an alkyl halide as a reaction raw material, and the reaction is performed in a state where at least one of hydrogen and nitrogen coexists with phosphine.
[0026]
(Phosphine raw material)
The raw material phosphine may be based on any production method. For example, (1) phosphine gas obtained by reacting red phosphorus with water vapor, and (2) by-product in the production of hypophosphorous soda. Phosphine gas obtained by subjecting the crude phosphine to dehydration, dearsine, and purification of the delowered hydrogenated phosphorus compound, (3) compressed phosphine gas (hereinafter referred to as compressed phosphine gas) compressed by a compressor, and (4) compressed phosphine Liquefied phosphine or the like obtained by liquefying gas and separating it from hydrogen is used. In the production method of the present invention, liquefied phosphine and compressed phosphine gas can be preferably used. In this compressed phosphine gas, hydrogen gas of 50 vol% or more is usually mixed as an impurity. In the present invention, this hydrogen gas can be used as it is as a phosphine raw material without being separated and removed.
[0027]
The addition amount of phosphine is usually 1.5 to 3 times mol, preferably 1.8 to 2.1 times mol for the alkyl bromide. The reason for this is that the reaction yield of primary phosphine tends to be low when the amount is less than 1.5 times mole, whereas the reaction proceeds even when the amount is more than 3 times mole, but the primary phosphine per batch is primary. The yield of phosphine is reduced and is not practical. The phosphine may be added to the reaction system all at once at the start of the reaction, or may be added separately during the start of the reaction. The amount of phosphine added here indicates the total amount of addition including those added during the reaction as well as at the start of the reaction.
[0028]
(Alkyl bromide)
In the first invention, an alkyl bromide represented by the following general formula (1) is used as the other reaction raw material.
[0029]
[Chemical 9]

[0030]
In general formula (1), R¹Represents a linear or branched alkyl group, cycloalkyl group, benzyl group or allyl group having 3 to 8 carbon atoms. Specific examples of the alkyl group include n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-hexyl group, iso-hexyl group, n-heptyl group, iso- A heptyl group, n-octyl group, iso-octyl group, etc. are mentioned, Among these, a C3-C6 alkyl group is preferable.
[0031]
In the second invention, an alkyl bromide represented by the following general formula (3) is used.
[0032]
[Chemical Formula 10]

[0033]
In general formula (3), R²Represents a linear or branched alkyl group, cycloalkyl group, benzyl group or allyl group having 1 to 16 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-hexyl group, iso-hexyl group, n -Heptyl group, iso-heptyl group, n-octyl group, iso-octyl group, n-decyl group, iso-decyl group, n-dodecyl group, iso-dodecyl group, n-tetradecyl group, iso-tetradecyl group, n -A hexadecyl group, iso-hexadecyl group, etc. are mentioned, Among these, a C1-C8 alkyl group is preferable.
[0034]
(catalyst)
As a catalyst tetraalkylphosphonium bromide, the following general formula (3)
[0035]
Embedded image

[0036]
(Wherein R^Three, R^Four, R^FiveAnd R⁶Represents the same or different linear or branched alkyl group having 1 to 18 carbon atoms. )
The phosphonium salt represented by these is used. In the general formula (3), R^Three~ R⁶Examples of the alkyl group include alkyl groups having 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, and a hexadecyl group. Specific examples of the compound include tributylmethylphosphonium bromide, Examples thereof include phosphonium salts such as tetrabutylphosphonium bromide, trioctylmethylphosphonium bromide, trioctylethylphosphonium bromide, tributyldodecylphosphonium bromide, tributylhexadecylphosphonium bromide, trioctylethylphosphonium bromide, and these are one kind or two or more kinds. Can be used.
[0037]
Among these phosphonium salts, tributyldodecylphosphonium bromide, tetrabutylphosphonium bromide, and tributylhexadecylphosphonium bromide are particularly preferable.
[0038]
The amount of tetraalkylphosphonium bromide added is usually from 0.1 to 3 mol%, preferably from 1 to 2 mol%, based on the alkyl halide. In the present invention, the introduction of this catalyst into the reaction system of tetraalkylphosphonium bromide is performed continuously by dividing the amount of catalyst required for the reaction into two or more times or by adjusting the addition rate, as will be described later. It is important to introduce the catalyst into the reaction system so that a necessary amount of the catalyst is present in the reaction system until the reaction is completed.
[0039]
Examples of the alkaline aqueous solution include aqueous alkali hydroxide solutions such as sodium hydroxide and potassium hydroxide, and among these, potassium hydroxide is preferable. These are usually used as an aqueous solution of 40 to 70% by weight, preferably 50 to 60% by weight, and the addition amount of the alkaline aqueous solution is usually 2.5 times mol or more, preferably 2.5 to It is 4 times mole, more preferably 3 times mole.
[0040]
Examples of the organic solvent include aromatics such as benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, anisole, nitrobenzene, and nitrotoluene: aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, ligroin, and cyclohexane. Class: Ether solvents such as diethyl ether, isopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, benzyl ether, dioxane, tetrahydrofuran, etc .: Alcohols such as methanol, ethanol, 2-propanol, 2-butanol, 2-methyl-2-propanol, etc .: Examples include organic polar solvents such as N, N-dimethylacetamide, hexamethylphosphoramide, sulfolane, and the like. Rukoto can. Of these organic solvents, toluene is particularly preferred.
[0041]
<Reaction conditions>
In the production method of the present invention, the above-described alkyl bromide, alkaline aqueous solution and organic solvent are charged in a reaction vessel in advance, and then phosphine gas is charged and heated to 60 ° C. or higher, and then the catalyst tetraalkylphosphonium bromide is reacted. Add to the system and react under pressure.
[0042]
This reaction is carried out in an aqueous alkali solution and an organic solvent, and phosphine is H⁺ Is removed and PH₂ ^-However, this process is facilitated by the presence of the catalytic tetraalkylphosphonium bromide, and PH₂ ^-Is (R¹)⁺-Br^-Or (R²)⁺-Br^-Reaction with (alkyl bromide) to produce the desired product R¹PH₂Or R²PH₂To obtain a primary phosphine.
[0043]
In addition, in the production method of the present invention, the above-mentioned catalyst may be added two or more times or continuously so that there is an amount of catalyst necessary for the reaction until the reaction is completed. An important requirement. The reason for this is that the catalyst tetraalkylphosphonium bromide reacts with an alkali source in the reaction system and decomposes, and this decomposition reaction proceeds competitively with the synthesis reaction of the desired primary phosphine. This is because the yield of primary phosphine, which is the target product, is lowered because the catalyst concentration is lowered. Therefore, it is preferable to add the catalyst tetraalkylphosphonium bromide into the reaction system gradually over time, or in several steps, and add in multiple stages. However, it may be appropriately selected depending on the convenience of the apparatus and the like, but it is industrially advantageous to add the catalyst in a multistage manner because the amount of the catalyst is easily controlled.
[0044]
More specifically, when the catalyst tetraalkylphosphonium bromide is added two or more times, the first addition amount is 0.05 to 2.0 mol%, preferably 0.5 The second and subsequent additions may be carried out with reference to about 1.0 mol% and 2-3 hours after the completion of the first addition. In the present invention, the addition in two or more portions is usually preferably performed in two portions. The second addition amount is 0.05 to 1.0 mol%, preferably 0.5 to 1.0 mol%, based on the alkyl halide.
[0045]
On the other hand, when the addition rate of the tetraalkylphosphonium bromide is adjusted and gradually added to the reaction system, it may be introduced gradually with 5 to 6 hours as a guide.
[0046]
The reaction temperature is usually 60 ° C. or higher, preferably 70 to 100 ° C. The reaction temperature is appropriately selected depending on the reactivity of the alkyl bromide and phosphine, but generally the lower alkyl bromide has a higher reactivity and the reaction proceeds even at a lower reaction temperature. However, when the reaction temperature is lower than 60 ° C., the reaction tends to be difficult to proceed, and the yield of the primary phosphine that is the target product is lowered, which is not preferable. In addition, when the reaction temperature is higher than 100 ° C., the amount of phosphine gas dissolved in the organic solvent that is the reaction field is reduced and the efficiency is deteriorated, and the pressure in the reaction system becomes excessively high, which is industrially disadvantageous. Therefore, it is not preferable.
[0047]
The reaction pressure varies depending on the type of phosphine gas used as a reaction raw material, and when liquefied phosphine is used, it is usually 0.5 MPa or more, preferably 0.5 to 1.5 MPa, and the reaction system contains at least hydrogen and nitrogen. When the reaction is carried out in the state where one kind is coexisting with phosphine, the reaction is carried out at 0.98 to 3.0 MPa, and when the compressed phosphine gas is used, the reaction is usually carried out at 0.98 to 3.0 MPa.
The reaction time is usually 5 hours or longer, preferably 10 to 15 hours.
[0048]
In the present invention, when the reaction is carried out in a state where at least one of hydrogen and nitrogen coexists with phosphine, phosphine is 40 Vol% or more, preferably 40 to 90 Vol%, and at least one of hydrogen and nitrogen is 60 Vol% or less. It is preferable to use a mixture of 10 to 60% by volume.
[0049]
The mixed gas may be added to the reaction system all at once at the start of the reaction, or may be added in several portions during and at the start of the reaction. The addition amount of phosphine is usually 1.5 to 3 with respect to the alkyl bromide as described above including the total addition amount including those added during the reaction as well as the start of the reaction. It is preferably in the range of double moles, preferably 1.8 to 2.1 times moles.
[0050]
In the present invention, when the reaction is performed using a compressed phosphine gas containing about 1 to 3 times (volume ratio) of hydrogen gas relative to the phosphine gas, the hydrogen gas is hardly dissolved in the organic solvent. When the entire amount is pressed into the reaction system, the pressure in the reaction system is usually 50 kg / cm.² Because of the high pressure described above, it is preferable to press-fit the compressed phosphine gas several times while the reaction proceeds to supplement the phosphine gas consumed in the reaction.
[0051]
When the reaction is carried out in the state where at least one of hydrogen and nitrogen coexists with the phosphine gas of the above raw material, the reaction proceeds in the same manner as in the case of using the phosphine gas that has undergone the above purification process, There is no byproduct of phosphine and tertiary phosphine compound, and the desired primary phosphine can be obtained in high yield.
Compressed phosphine gas (PH_Three: H₂= 40: 60 (vol%)), the same yield as when liquefied phosphine is used is obtained, and the product also has a high target primary phosphine purity. Is obtained.
[0052]
Phosphine gas and H₂, N₂When a mixed gas such as an inert gas is used for the reaction, the phosphine gas dissolves in the organic solvent and is consumed for the reaction with the alkyl halide, but the inert gas does not participate in the reaction with the alkyl halide. The reaction between the phosphine gas and the alkyl halide in the mixed gas is carried out in an organic solvent, and the yield is the same as when liquefied phosphine is used, and the product has the same high target primary phosphine purity. It is. Furthermore, since the phosphine gas is consumed for the reaction, the concentration of the unreacted phosphine gas is relatively lowered after the reaction. For this reason, compared with the case where liquefied phosphine gas is used for the reaction, the residual gas has a low concentration of highly toxic phosphine gas, and has an advantage that safety is improved in terms of toxicity.
[0053]
After completion of the above reaction, unreacted phosphine gas remaining in the reaction vessel, and hydrogen gas and nitrogen gas coexist to react, and when the reaction is performed, unreacted phosphine gas, hydrogen gas and nitrogen gas are separated. It is preferable. In this case, the inside of the reaction vessel is replaced with an inert gas such as nitrogen gas, and if necessary, heated and refluxed to leave the solvent and primary phosphine in the reaction vessel, while maintaining the phosphine gas, hydrogen gas, and nitrogen gas. Can be discharged out of the system, the reaction solution can be collected and separated into a product.
Thus, the desired primary phosphine can be obtained selectively and in high yield.
[0054]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[0055]
Test example 1
<Catalytic degradation test>
Under room temperature, 105.3 g (1.05 mol) of 56% KOH aqueous solution, 100 ml of toluene, and 47.9 g (0.35 mol) of 1-bromobutane were charged into a 300 ml four-necked flask and stirred at 400 rpm using a stirrer. Here, 2.41 g (4.72 mmol) of tri-n-butylhexadecylphosphonium bromide was charged, and after 10 minutes, the toluene phase in the reaction solution was sampled.³¹P NMR analysis was performed. Then, the temperature was raised to 40 ° C. or 80 ° C. with stirring, and the toluene phase was collected again after 1 hour.³¹P NMR analysis was performed. The results are shown in Table 1.
[0056]
From Table 1, it can be seen that tri-n-butylhexadecylphosphonium bromide, which is a phosphonium salt, is decomposed into tri-n-butylphosphine oxide one hour after contact with alkali at 40 ° C. and 80 ° C. .
[0057]
In addition, the water phase 1 hour after contact with alkali³¹As a result of P NMR analysis, it was found that both tri-n-butylhexadecylphosphonium bromide and tri-n-butylphosphine oxide had a smaller peak than that of the toluene phase and were hardly dissolved in the aqueous phase. From the above results, it is suggested that tri-n-butylhexadecylphosphonium bromide is almost completely decomposed in 1 hour after contact with alkali.
[0058]
[Table 1]

[0059]
(note)
PX-416B: Tri-n-butylhexadecylphosphonium bromide
PO-4: Tri-n-butylphosphine oxide
[0060]
Example 1
At room temperature, 105.4 g (1.05 mol) of 56% KOH aqueous solution, 70 ml of toluene, and 48.0 g (0.35 mol) of 1-bromobutane were charged into a 1 L autoclave, sufficiently purged with nitrogen, and then stirred at 400 rpm using a stirrer. did. Here, 23.8 g (0.7 mol) of liquefied phosphine gas was charged. Thereafter, the temperature was raised to 80 ° C. The internal pressure when the temperature reached 80 ° C. was 1.5 MPa.
[0061]
Subsequently, 50% by weight of a solution of 2.4 g (4.72 mmol) of tri-n-butylhexadecylphosphonium bromide dissolved in 30 ml of toluene was injected over 10 minutes. The internal pressure after the press-fitting was 1.35 MPa. After aging at 80 ° C. for 2 hours, the remaining 50% by weight of a solution of tetra-n-butylphosphonium bromide in toluene was again injected over 10 minutes. After completion of the press-fitting, the internal pressure was 0.91 MPa. This temperature was kept overnight. The internal pressure after completion of the reaction was 0.85 MPa.
[0062]
After cooling to room temperature, 50 g of water was injected and stirred for a while to dissolve the by-produced KBr, unreacted phosphine gas was released until the pressure reached normal pressure. Then, nitrogen gas was pressurized to about 1.5 MPa and added to the autoclave, and the operation of releasing to normal pressure was repeated several times to sufficiently substitute nitrogen. Thereafter, the inside of the autoclave was again pressurized to about 0.3 MPa with nitrogen gas and separated to discard the aqueous phase. Further, 100 ml of water was added and washed with water. After standing, the aqueous phase was separated and discarded to obtain a target toluene solution of mono-normal butylphosphine.
The product was analyzed by gas chromatography (GC analysis).
[0063]
Example 2
A 1 L autoclave charged with 105.4 g (1.05 mol) of 56% KOH aqueous solution, 70 ml of toluene and 48.0 g (0.35 mol) of 1-bromobutane was sufficiently purged with nitrogen at room temperature, and stirred with a stirrer at 400 rpm. The liquid phosphine gas 23.8g (0.7mol) was prepared here. Next, the temperature was raised to 80 ° C. The internal pressure when the temperature reached 80 ° C. was 1.5 MPa.
[0064]
Next, a solution of 1.3 g (3.8 mmol) of tetra-n-butylphosphonium bromide dissolved in 30 ml of toluene was injected over 20 minutes. The internal pressure after the press-fitting was 1.0 MPa. After aging at 80 ° C. for about 2 hours, 1.2 g (3.5 mmol) of tetra-n-butylphosphonium bromide dissolved in 30 ml of toluene was again injected over 20 minutes. After completion of the press-fitting, the internal pressure was 0.6 MPa. This temperature was kept overnight. The internal pressure after completion of the reaction was 0.57 MPa.
[0065]
After cooling to room temperature, 50 g of water was injected and stirred for a while to dissolve KBr produced as a by-product, unreacted phosphine gas was released to normal pressure. Then, nitrogen gas was pressurized to about 1.5 MPa and added to the autoclave, and the operation of releasing to normal pressure was repeated several times to sufficiently substitute nitrogen. Thereafter, the inside of the autoclave was again pressurized to about 0.3 MPa with nitrogen gas and separated to discard the aqueous phase. Further, 100 ml of water was added and washed with water. After standing, the aqueous phase was separated and discarded to obtain a target toluene solution of mono-normal butylphosphine.
The product was analyzed by gas chromatography.
[0066]
Example 3
A 1 L autoclave charged with 105.4 g (1.05 mol) of 56% KOH aqueous solution, 100 ml of toluene and 48.0 g (0.35 mol) of 1-bromobutane was sufficiently purged with nitrogen at room temperature, and stirred with a stirrer at 400 rpm. Here, 23.8 g (0.7 mol) of liquefied phosphine gas was charged. Next, the temperature was raised to 60 ° C. The internal pressure when the temperature reached 60 ° C. was 1.25 MPa.
[0067]
Next, a solution of 1.6 g (3.5 mmol) of tri-n-butyldodecylphosphonium bromide dissolved in 30 ml of toluene was injected over 15 minutes. The internal pressure after the press-fitting was 1.15 MPa. After aging at 60 ° C. for about 2 hours, 1.6 g (3.5 mmol) of tri-n-butyldodecylphosphonium bromide dissolved in 30 ml of toluene was again injected over 15 minutes. After completion of the press-fitting, the internal pressure was 0.9 MPa. This temperature was kept overnight. The internal pressure after completion of the reaction was 0.7 MPa.
[0068]
After cooling to room temperature, 50 g of water was injected and stirred for a while to dissolve KBr produced as a by-product, unreacted phosphine gas was released to normal pressure. Next, nitrogen gas was pressurized to about 1.5 MPa and added to the autoclave, and the operation of releasing to normal pressure was repeated several times to sufficiently substitute nitrogen. Thereafter, the inside of the autoclave was again pressurized to about 0.3 MPa with nitrogen gas and separated to discard the aqueous phase. Further, 100 ml of water was added and washed with water. After standing, the aqueous phase was separated and discarded to obtain a target toluene solution of mono-normal butylphosphine.
The product was analyzed by gas chromatography.
[0069]
Comparative Example 1
At room temperature, charged with 9.96 g (99.4 mmol) of 56% KOH aqueous solution, 19 ml of toluene, 5.29 g (38.6 mmol) of 1-bromobutane, and 0.22 g (0.43 mmol) of tri-n-butylhexadecylphosphonium bromide. The autoclave was sufficiently purged with nitrogen and stirred at 300 rpm with a stirrer. Here, 2.27 g (66.7 mmol) of phosphine gas was charged. Thereafter, the temperature was raised to 60 ° C. The internal pressure when the temperature reached 60 ° C. was 0.65 MPa. Hold at this temperature overnight. The internal pressure after completion of the reaction was 0.6 MPa.
[0070]
After cooling to room temperature and injecting 10 g of water and stirring for a while to dissolve KBr produced as a by-product, unreacted phosphine gas was released to normal pressure. Then, nitrogen gas was pressurized to about 1.5 MPa and added to the autoclave, and the operation of releasing to normal pressure was repeated several times to sufficiently substitute nitrogen. Thereafter, the inside of the autoclave was again pressurized to about 0.3 MPa with nitrogen gas and separated to discard the aqueous phase. Further, 100 ml of water was added and washed with water. After standing, the aqueous phase was separated and discarded to obtain a target toluene solution of mono-normal butylphosphine.
The product was analyzed by gas chromatography. The results are shown in Table 3.
[0071]
Comparative Example 2
The reaction was performed in the same manner as in Comparative Example 1 except that the reaction temperature was 40 ° C.
The product was analyzed by gas chromatography.
[0072]
Comparative Example 3
The reaction was performed in the same manner as in Example 1 except that 1-chlorobutane was used instead of 1-bromobutane.
The product was analyzed by gas chromatography.
[0073]
Comparative Example 4
The reaction was performed in the same manner as in Example 1 except that the amount of 56% KOH used was changed to 3 times mol and changed to 2 times mol with respect to 1-bromobutane of Example 1.
[0074]
Comparative Example 5
The reaction was performed in the same manner as in Example 1 except that 1-bromohexadecane was used instead of 1-bromobutane in Example 1.
[0075]
Table 2 shows the experimental conditions of Examples 1 to 3 and Comparative Examples 1 to 6, and Table 3 shows the results.
[0076]
[Table 2]

[0077]
(note)
RX: Alkyl halide
PH_Three : Phosphine
BuBr: 1-bromobutane
BuCl: 1-chlorobutane
C₁₆H₃₃Br: 1-bromohexadecane
416B: tri-n-butylhexadecylphosphonium bromide
4B: Tetra n-butylphosphonium bromide
412B: Tri-n-butyldodecylphosphonium bromide
[0078]
[Table 3]

[0079]
(note)
RX: Alkyl halide
BuPH₂ : Mono-normal butyl phosphine
BuBr: 1-bromobutane
BuCl: 1-chlorobutane
C₁₆H₃₃Br: 1-bromohexadecane
[0080]
Example 4
A 1 L autoclave charged with 105.4 g (1.05 mol) of a 56% aqueous potassium hydroxide solution, 70 ml of toluene and 48.0 g (0.35 mol) of 1-bromobutane at room temperature was thoroughly purged with nitrogen, and stirred at 400 rpm with a stirrer. did. 11.0 g (phosphine 0.300 mol, hydrogen 0.392 mol) of phosphine compressed gas (phosphine gas 43.4 vol%, hydrogen gas 56.6 vol%) by-produced from the sodium hypophosphite production process was charged. Thereafter, the temperature was raised to 80 ° C. The internal pressure at that time was 2.2 MPa.
[0081]
Subsequently, a solution of 2.4 g (4.72 mmol) of tri-n-butylhexadecylphosphonium bromide dissolved in 30 ml of toluene was first press-fitted with 15% by weight over 15 minutes. The internal pressure after the press-fitting was 2.2 MPa. Holding at this temperature for 2 hours, when the internal pressure decreased to 2.1 MPa, the unreacted compressed gas was released to normal pressure, and 10.0 g of phosphine compressed gas by-produced again from the sodium hypophosphite production process was released. (Phosphine 0.273 mol, hydrogen 0.356 mol) was charged. The internal pressure at this time was 2.4 MPa. Further, a toluene solution of 33% by weight of tri-n-butylhexadecylphosphonium bromide was injected and charged over 7 minutes. The internal pressure in the reaction system at this time was 2.4 MPa. Again, the phosphine compressed gas produced as a by-product from the sodium hypophosphite production process is released again when the internal pressure drops to 2.1 MPa when the internal pressure drops to 2.1 MPa. Was charged with 6.0 g (phosphine 0.163 mol, hydrogen 0.214 mol). The internal pressure at this time was 1.8 MPa. Further, the remaining 33% by weight of a solution of tri-n-butylhexadecylphosphonium bromide in toluene was injected over 8 minutes. The internal pressure in the reaction system at this time was 1.8 MPa. The reaction was terminated by maintaining the temperature at 80 ° C. overnight. The internal pressure at this time was 1.7 MPa.
[0082]
Next, after cooling to room temperature, 100 g of water was injected and stirred for a while, and then the unreacted phosphine gas was released to normal pressure. Next, nitrogen gas was pressurized to about 1.5 MPa and added to the autoclave, and the operation of releasing to normal pressure was repeated several times to sufficiently substitute nitrogen.
[0083]
Thereafter, the inside of the autoclave was again pressurized to about 0.3 MPa with nitrogen gas and separated to discard the aqueous phase. Further, 100 ml of water was added and washed with water. After standing, the aqueous phase was separated and discarded to obtain a target toluene solution of mono-normal butylphosphine.
The product was analyzed by gas chromatography.
[0084]
Example 5
The reaction was carried out in the same manner as in Example 4 except that the addition temperature of the catalyst tri-n-butylhexadecylphosphonium bromide was 100 ° C.
The product was analyzed by gas chromatography.
[0085]
Example 6
Except for charging 23.8 g (0.70 mol) of liquefied phosphine gas instead of 23.8 g (0.70 mol) of liquefied phosphine gas of Example 2, this was carried out except that 0.6 g (0.30 mol) of hydrogen was charged. The reaction was carried out in the same manner as in Example 2.
[0086]
Example 7
Except that 23.8 g (0.70 mol) of liquefied phosphine gas was charged instead of 23.8 g (0.70 mol) of liquefied phosphine gas of Example 2, then 8.4 g (0.30 mol) of nitrogen was charged. Reaction was carried out in the same manner as in 2.
[0087]
Example 8
Instead of 23.8 g (0.70 mol) of the liquefied phosphine gas of Example 2, 23.8 g (0.70 mol) of liquefied phosphine gas was charged, and then 0.4 g of hydrogen (0.20 mol) and 2.8 g of nitrogen (0.8. The reaction was carried out in the same manner as in Example 2 except that 10 mo1) was charged.
[0088]
Example 9
Instead of 23.8 g (0.70 mol) of the liquefied phosphine gas of Example 2, 23.8 g (0.70 mol) of liquefied phosphine gas was charged, then 0.6 g (0.30 mol) of hydrogen was charged, and 1-bromobutane 48. The reaction was carried out in the same manner as in Example 2, except that 77.41 g (0.35 mol) of 1-bromodecane was used instead of 0 g (0.35 mol) and the temperature was 100 ° C. instead of 80 ° C.
[0089]
The reaction conditions of Examples 4 to 9 are shown in Table 4, and the results are shown in Table 5.
[0090]
[Table 4]

[0091]
(note)
RX: Alkyl halide
BuBr: 1-bromobutane
C_TenH_{twenty one}Br: 1-bromodecane
[0092]
[Table 5]

[0093]
(note)
RX: Alkyl halide
RPH₂: Primary phosphine
[0094]
Example 10
The reaction was performed in the same manner as in Example 1 except that an aqueous NaOH solution was used instead of the aqueous KOH solution. Although the yield was slightly lower than in Example 1, mono-normal butylphosphine was obtained.
[0095]
【The invention's effect】
As described above, according to the production method of the present invention, the desired primary phosphine can be produced with a higher yield than when the entire amount of the catalyst is introduced at once.
Furthermore, even if hydrogen and nitrogen are used in the reaction system in the presence of phosphine, almost no by-products are produced, and only the desired primary phosphine can be obtained in good yield.

Claims (12)

In the method for producing a primary phosphine by reacting phosphine and an alkyl halide in an aqueous alkali solution and an organic solvent in the presence of a catalyst, the following general formula (1) is used as the alkyl halide.

(In the formula, R ¹ represents a linear or branched alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, a benzyl group, or an allyl group.)
Using tetraalkylphosphonium bromide as a catalyst, the molar ratio of phosphine to alkyl bromide is 1.5 times mol or more, and the catalyst required for the reaction is divided into two or more times. Or continuously added into the reaction system with the addition rate adjusted, and the reaction is carried out at 60 ° C. or higher.

(Wherein R ¹ has the same meaning as described above). The method for producing a primary phosphine according to claim 1, wherein the reaction is performed under a pressure of 0.5 MPa or more. The method for producing a primary phosphine according to claim 1, wherein the tetraalkylphosphonium bromide of the catalyst is at least one selected from tributylhexadecylphosphonium bromide, tetrabutylphosphonium bromide and tributyldodecylphosphonium bromide. The method for producing a primary phosphine according to claim 1, wherein the aqueous alkaline solution is an aqueous potassium hydroxide solution. The method for producing a primary phosphine according to claim 1, wherein the addition amount of the alkali is 2.5 times mole or more per mole of alkyl bromide. In the method for producing primary phosphine by reacting phosphine and alkyl halide in an alkaline aqueous solution and an organic solvent in the presence of a catalyst, in a state where at least one of hydrogen and nitrogen coexists with phosphine in the reaction system, The following general formula (3) as alkyl halide

(In the formula, R ² represents a linear or branched alkyl group, cycloalkyl group, benzyl group or allyl group having 1 to 16 carbon atoms.)
Using tetraalkylphosphonium bromide as a catalyst, the molar ratio of phosphine to alkyl bromide is 1.5 times mol or more, and the catalyst required for the reaction is divided into two or more times. Or continuously added into the reaction system after adjusting the addition rate, and the reaction is carried out at 60 ° C. or higher.

(Wherein R ² has the same meaning as described above). The reaction system in which at least one of hydrogen and nitrogen coexists with phosphine is a reaction using a compressed phosphine gas obtained by compressing a phosphine gas containing hydrogen gas by-produced during the production of sodium hypophosphite. The method for producing a primary phosphine according to claim 6. The method for producing a primary phosphine according to claim 6 or 7, wherein the compressed phosphine gas is introduced into the reaction system in two or more times. The method for producing a primary phosphine according to claim 6, wherein the reaction is performed under a pressure of 0.98 to 3.0 MPa. The method for producing a primary phosphine according to claim 6, wherein the tetraalkylphosphonium bromide of the catalyst is at least one selected from tributylhexadecylphosphonium bromide, tetrabutylphosphonium bromide, and tributyldodecylphosphonium bromide. The method for producing primary phosphine according to claim 6, wherein the aqueous alkaline solution is an aqueous potassium hydroxide solution. The method for producing a primary phosphine according to claim 6, wherein the addition amount of the alkali is 2.5 times mol or more per 1 mol of alkyl bromide.