JP4505947B2 - Co-production method of 2,3-dimethylbutene-1 and 2,3-dimethylbutene-2 - Google Patents

Description

（式中、Ｘ₁〜Ｘ₅は同一または相異なり、ハロゲンまたは水素原子を表し、少なくとも一つはハロゲン原子である。）
で示されるハロゲン化フェノール類、および
（Ｅ）スルホン酸類及びジアルキル硫酸類から選ばれる少なくとも１種の硫黄化合物、
からなるニッケル錯体触媒。
【０００６】
【発明の実施の形態】
以下、本発明について詳細に説明する。本発明に使用されるプロピレン二量化触媒成分(A)のニッケル化合物としては、例えば、ナフテン酸ニッケル、ギ酸ニッケル、酢酸ニッケルなどのニッケルの有機酸塩、塩化ニッケル、シュウ化ニッケル、硝酸ニッケルなどのニッケルの無機酸塩、ニッケルビスアセチルアセトナートなどのニッケルの錯化合物などが挙げられる。これらのニッケル化合物は、２種以上使用することもできる。
【０００７】
触媒成分(B)のトリアルキルアルミニウムとしては、例えば、トリメチルアルミニウム、トリエチルアルミニウム、トリ-n-プロピルアルミニウム、トリ-n-ブチルアルミニウム、トリイソブチルアルミニウム、トリ-n-ペンチルアルミニウム、トリ-n-ヘキシルアルミニウムなどが挙げられる。触媒成分(B)は、触媒成分(A)に対して、通常2〜500モル倍程度、好ましくは2〜100モル倍程度使用される。
【０００８】
触媒成分(C)の３価のリン化合物としては、例えばトリイソプロピルホスフィン、トリ-t-ブチルホスフィン、トリ-sec-ブチルホスフィン、トリシクロヘキシルホスフィン、エチル-ジ-t-ブチルホスフィン、トリ-o-トリルホスフィン、トリベンジルホスフィンなどが挙げられる。
触媒成分(C)は、触媒成分(A)に対し、通常0.1〜20モル倍程度、好ましくは0.5〜２モル倍程度使用される。
【０００９】
触媒成分(D)のフッ素化イソプロパノールとしては、例えば1,1,3,3-テトラフルオロイソプロパノール、1,1,1,3,3-ペンタフルオロイソプロパノール、1,1,1,3,3,3-ヘキサフルオロイソプロパノール等が挙げられる。
また、一般式（２）で示されるハロゲン化フェノール類としては、例えばo-、m-、p-クロロフェノール、2,3-、2,4-、2,5-、2,6-、3,4-および3,5-ジクロロフェノール、2,4,5-および2,4-6-トリクロロフェノール、2,3,4,6-テトラクロロフェノール、ペンタクロロフェノールなどが挙げられる。
【００１０】
触媒成分(D)は、触媒成分(B)に対して、通常0.4〜20モル倍程度、好ましくは1〜10モル倍程度使用される。
【００１１】
触媒成分(E)の硫黄化合物としては、例えばメタンスルホン酸、エタンスルホン酸等の脂肪族スルホン酸類、ベンゼンスルホン酸、p-トルエンスルホン酸等の芳香族スルホン酸類、クロロスルホン酸、トリフルオロメタンスルホン酸等のハロゲン含有スルホン酸類などのスルホン酸類、ジメチル硫酸、ジエチル硫酸類が挙げられる。これらは２種以上混合して使用することもできる。
【００１２】
触媒成分(E)は、触媒成分(A)に対して、通常0.1-10モル倍程度使用される。
【００１３】
触媒の調製は、通常、不活性溶媒の存在下に実施され、例えば、トルエン、クロロベンゼン、ヘキサン、ヘプタン、ジクロロエタンなどが挙げられる。
触媒成分の混合順序に特に規制はないが、触媒成分の混合はブタジエン、イソプレンなどの共役ジエンの存在下に行うのが好ましく、この場合は特に安定性に優れた触媒を得ることができる。該共役ジエンは触媒成分(A)に対して1〜200モル倍程度使用するのが好ましい。
【００１４】
触媒の調製温度は通常-50〜30℃程度で行われる。プロピレン二量化反応は不活性溶媒、例えば、トルエン、クロロベンゼン、ヘキサン、ヘプタン、ジクロロエタン中で実施される。反応時触媒成分の濃度は、ニッケル原子として10^-5〜10^-10mol/l程度である。
また、反応温度は通常-20〜50℃程度、反応時間は通常 30分〜100時間程度、系内の圧力は通常0〜30kg/cm²G程度である。
【００１５】
かくして得られたプロピレン二量化反応液をそのまま精留してＤＭＢ−１を得てもよいし、二量化触媒を失活除去してからＤＭＢ−１蒸留を行ってもよい。プロピレン二量化失活剤としては、例えばアンモニア水、アミン類の水溶液、水酸化ナトリウム水溶液、水酸化カリウム水溶液などの水性の失活剤が挙げられる。これらの水性の失活剤を用いた場合、通常、ＤＭＢ−１を含む油層から水層を除去した後に蒸留を行う。
【００１６】
ＤＭＢ−１蒸留工程においては、精留により純度92%以上のＤＭＢ−１を取得することができる。即ち、プロピレン二量体生成混合物のうち、沸点の低いＤＭＢ−１は初留分として取得することができるし、必要によっては、プロピレン二量化生成物混合物のうちの最低沸点の４−メチルペンテン−１を塔頂から留出させた後、目的とするＤＭＢ−１を留出させて得ることができる（前留分ＤＭＢ−１）。
プロピレン二量化液中に存在するＤＭＢ−１の量のうち、塔頂から留出させるＤＭＢ−１の量は所望により任意に変えることができ、言い換えれば塔底に任意の量のＤＭＢ−１を残すことができるが、通常は、プロピレン二量化液中に存在するＤＭＢ−１の量のうち、塔頂から留出させるＤＭＢ−１の割合は15%から85%である。残留するＤＭＢ−１はそのまま取り出してもよいし、後留分として蒸留により塔頂から取り出してプロピレン３量体以上の高沸点物と分離してもよい（後留分ＤＭＢ−１）。
【００１７】
かくして得られる残留するＤＭＢ−１または後留分ＤＭＢ−１は異性化触媒を用いることによりＤＭＢ−２に変換することができる。
異性化触媒としては、例えば硫酸、メタンスルホン酸、エタンスルホン酸などの脂肪族スルホン酸、スルホン酸基を含む強酸性イオン交換樹脂、ケイタングステン酸などのヘテロポリ酸等が挙げられる。
【００１８】
用いる硫酸の濃度については通常70%以上、好ましくは90-98%程度である。硫酸の添加量は酸の濃度にもよるがＤＭＢ−１に対して0.05〜3wt%程度である。スルホン酸類の添加量もＤＭＢ−１に対して0.05〜3wt%程度である。
【００１９】
スルホン酸基を含む強酸性イオン交換樹脂やヘテロポリ酸を異性化触媒として用いる場合には、液相または気相にてバッチ法または連続法でＤＭＢ−１からＤＭＢ−２へ異性化することができる。異性化反応をバッチ法で行う場合、強酸性イオン交換樹脂やヘテロポリ酸触媒はＤＭＢ−１に対して0.1〜1wt%程度使用される。連続反応の場合は、ＤＭＢ−１を含む混合物を、1〜100/h^-1程度の空間速度で該触媒の充填された反応管に流通させて異性化反応をすることができる。
【００２０】
異性化反応は、溶媒を用いても用いなくても進行させることができる。溶媒を用いる場合は、通常ベンゼン、トルエンなどの芳香族炭化水素、ヘキサン、ヘプタンなどの脂肪族炭化水素のような不活性溶媒が用いられる。これらの不活性溶媒は、通常ＤＭＢ−１に対して0.01〜10重量倍程度使用される。また、かかる溶媒の代わりに異性化後の反応液を異性化反応時の溶媒として用いることもできるし。異性化反応時の温度は通常-30〜100℃程度、好ましくは0〜60℃程度である。
【００２１】
かくしてＤＭＢ−１はＤＭＢ−２に異性化されるが、硫酸やスルホン酸類を異性化触媒に用いた場合は、異性化後の反応混合物にアルカリ水溶液を加えて攪拌した後、分液によって酸触媒を除去することができる。
イオン交換樹脂またはヘテロポリ酸を異性化触媒として用い、バッチ法で異性化反応した場合には通常反応混合物を濾過して触媒を分離して次の蒸留を行うことができ、連続法で異性化した場合は反応液をそのまま次の蒸留に用いることができる。
【００２２】
かくして得られるＤＭＢ−２を含む反応混合物を蒸留することにより純度99%以上のＤＭＢ−２を得ることができる。
【００２３】
【発明の効果】
本発明は、優れたプロピレン二量化活性をもち、優れたＤＭＢ−１選択性をもつプロピレン二量化触媒を用いて得られるプロピレン二量化反応液を蒸留することによって高い純度のＤＭＢ−１を取得し、さらにＤＭＢ−１を含む蒸留残液を酸触媒によってＤＭＢ−２を含む反応液に変換して蒸留することにより高い純度のＤＭＢ−２を得る効率的なＤＭＢ−１およびＤＭＢ−２を併産する方法を提供することができる。
【００２４】
【実施例】
以下、本発明を実施例を挙げてより具体的に説明するが、本発明はこれら実施例に限定されるものではない。
[実施例1]
（プロピレン二量化触媒液の調製）
50mlのシュレンク管を窒素置換した後、５℃に冷却し、同温度にてこれにナフテン酸ニッケル0.1mmolを含むトルエン溶液を1.35ml、トリシクロヘキシルホスフィン0.1mmolおよびイソプレン8mmolを入れ、さらにトリエチルアルミニウム1.0mmolを含むトルエン溶液を加えた。次いでトリフルオロメタンスルホン酸0.1mmolを加えた後、1,1,1,3,3,3-ヘキサフルオロイソプロパノール1.5mmolを加えて、これをプロピレン二量化触媒液とした。
【００２５】
[実施例2]
（プロピレン二量化反応）
窒素置換した1500mlのステンレス製オートクレーブに１０℃にて上記触媒液全量とトルエン４０ｍｌを加えた後プロペンを3kg/cm2Gに保圧して供給し、１０℃、2時間反応させた。反応液を５℃まで冷却した後、未反応のプロペンを系外に除いた。反応混合物をガスクロマトグラフィーで分析した結果を下記表１に示す。
【表１】

註）
4M1P：４−メチルペンテン−１、4M2P：シス、トランス−４−メチルペンテン−２、2M1P：２−メチルペンテンー１、2M2P：２−メチルペンテン−２、
二量体選択率：反応したプロペン中のプロピレン二量化生成物割合x 100
ＤＭＢ−１ T.O.N.：ＤＭＢ−１生成量（mmol）/触媒ニッケル量（mmol）
【００２６】
[実施例3]
（ＤＭＢ−１蒸留）
得られたプロピレン二量化反応液に対し１重量倍程度の2%水酸化ナトリウム水溶液を加え、40℃、1h攪拌した後、20℃に下げた後、分液して油層550gを取得した。
得られた反応混合物550g（ＤＭＢ−１ 320g含有）を50段精留塔を使用して常圧にて蒸留した。蒸留は、最初全環流を３時間行い、次いで環流比30：1で塔頂より272gの留分（54-56℃）を取り出した。この留分のＤＭＢ−１の純度は94%（ＤＭＢ−１前留分、ＤＭＢ−１回収率80%）であった。さらに蒸留残渣を環流比30：1にて56-58℃の留分を81g取得した。
この留分のＤＭＢ−１の純度は75%であった（ＤＭＢ−１後留分、ＤＭＢ−１回収率 19%）。
【００２７】
[実施例4]
（ＤＭＢ−１→ＤＭＢ−２異性化）
実施例３で得られたＤＭＢ−１後留分80gに対し、90%硫酸を0.4wt%添加して30℃にて3h反応させた。つづいて、5%水酸化ナトリウム水溶液を反応液に対して50wt%加え、25℃、0.5時間撹拌した後、分液して油層80gを取得した。反応液をガスクロマトグラフィーにより分析した結果、ＤＭＢ−１＋ＤＭＢ−２に対するＤＭＢ−２の比率は91.0%、ＤＭＢ−２純分で 52gであった。
【００２８】
[実施例5]
反応管（内径7mm、長さ15cm）に2mlのアンバーリスト15（強酸性イオン交換樹脂）を充填した後、実施例３と同様に実施して得られたＤＭＢ−１後留分８０ｇ（純度７５%）を50℃、11.2ml/hrにて8時間流通させた。得られた反応液は67gであり、ＤＭＢ−１＋ＤＭＢ−２に対するＤＭＢ−２の比率は91.5%、
ＤＭＢ−２の含量は45.6gであった。
【００２９】
[実施例6]
反応管（内径7mm、長さ15cm）に、活性炭に担持し焼成したケイタングステン酸0.94g（2ml）を充填した後、実施例３と同様に実施して得られたＤＭＢ−１後留分８０ｇ（純度７５%）を20℃、11.2ml/hrにて8時間流通させた。得られた反応液は67gであり、ＤＭＢ−１＋ＤＭＢ−２に対するＤＭＢ−２の比率は91.2%、ＤＭＢ−２の含量は45.3gであった。
【００３０】
[実施例7]
（ＤＭＢ−２蒸留）
実施例４で得られた反応液８０ｇを、30段の精留塔を用い、常圧にて蒸留した。蒸留は、最初全環流2時間行い、つづいて環流比36：1の下でＤＭＢ−１、4M2P、2M1P、2M2Pを塔頂より留出させ、除外した（50-68℃の留分）。次に環流比を10：1に下げて68-73℃の留分を塔頂より35g取得した。この留分をガスクロマトグラフィーで分析するとＤＭＢ−２の純度は99.0%であった。
【００３１】
[実施例8]
実施例５で得られた反応液６７ｇを用いた以外は実施例７に準拠して行った。ＤＭＢ−２留分は30gであり、ＤＭＢ−２の純度は99.0%であった。
【００３２】
[実施例９]
実施例６で得られた反応液６７ｇを用いた以外は実施例７に準拠して行った。ＤＭＢ−２留分は30gであり、ＤＭＢ−２の純度は99.0%であった。[0001]
BACKGROUND OF THE INVENTION
In the present invention, after dimerizing propylene using a nickel complex catalyst, 2,3-dimethylbutene-1 (hereinafter referred to as DMB-1) and 2,3-dimethylbutene- having excellent purity from the reaction solution are used. 2 (hereinafter referred to as DMB-2).
[0002]
[Prior art]
DMB-1 and DMB-2 are important compounds as basic intermediates for agricultural chemicals, medicines, fragrances, cosmetics and the like. As a method of producing DMB-1 and DMB-2, for example, propylene is dimerized in the presence of a nickel complex catalyst, and the resulting DMB-1 is isomerized with an isomerization catalyst to prepare a reaction solution rich in DMB-2. This is obtained as DMB-2 by distillation, and the obtained DMB-2 is distilled as it is isomerized to DMB-1 in the presence of a solid acid catalyst to obtain DMB-1 (Patent No. 1). No. 2577772).
[0003]
[Problems to be solved by the invention]
When the nickel complex catalyst described in the above document is used, the selectivity of DMB-1 in the propylene dimerization process is not satisfactory, and there are many by-products of several isomers having boiling points close to those of DMB-1. For example, the by-products 4-methylpentene-1, cis and trans-4-methylpentene-2 have a boiling point difference from DMB-1 of only 1 to 3 ° C. and are superior from these mixtures containing DMB-1. It is difficult to obtain DMB-1 having high purity (purity 92% or more). Therefore, in the above prior art, in order to obtain high purity DMB-1, first, a propylene dimerization reaction solution containing DMB-1 is converted into a reaction solution containing DMB-2 that can be easily separated from other isomers. Then, high purity DMB-2 is obtained by distillation, and this high purity DMB-2 is distilled while contacting with an isomerization catalyst and performing reverse isomerization to DMB-1. It was necessary to go through a long process of obtaining -1.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors dimerized propylene using a nickel complex catalyst having excellent propylene dimerization activity and excellent DMB-1 selectivity. DMB-1 having an excellent purity (purity of 92% or more) is obtained by distilling the liquid, and then the distillation residue containing DMB-1 is contacted with an acid catalyst to convert DMB-1 to DMB-2. The present inventors have found a method for producing both DMB-1 and DMB-2 having excellent purity by an extremely efficient method of obtaining DMB-2 having excellent purity by distilling the reaction solution.
[0005]
That is, the present invention dimerizes propylene using the following nickel complex catalyst as a propylene dimerization catalyst having excellent propylene dimerization activity and excellent DMB-1 selectivity (propylene dimerization step), and the reaction obtained After 2,3-dimethylbutene-1 was obtained by rectifying the liquid (dimethylbutene-1 distillation step), the distillation residue was brought into contact with sulfuric acid, sulfonic acid, or heteropolyacid, 2,3-dimethylbutene-1 was isomerized to 2,3-dimethylbutene-2 (isomerization step), and the reaction solution was rectified to obtain 2,3-dimethylbutene-2 (dimethylbutene-2). 2 distillation step), and a method for co-production of 2,3-dimethylbutene-1 and 2,3-dimethylbutene-2.
(A) at least one nickel compound selected from organic acid salts, inorganic acid salts and complex compounds of nickel,
(B) trialkylaluminum,
(C) General formula (1)
PR ¹ R ² R ³ (1)
Wherein R ¹ , R ² and R ³ are the same or different and each represents a phenyl group, an alkyl group, a cycloalkyl group or an aralkyl group which may be substituted with alkyl or alkoxy. N is 1 to 6 Represents an integer.)
A trivalent phosphorus compound represented by:
(D) Fluorinated isopropanol or general formula (2)

(Wherein, X _{1 to} X ₅ are the same or different and represent a halogen or a hydrogen atom, and at least one is a halogen atom.)
And (E) at least one sulfur compound selected from sulfonic acids and dialkyl sulfates,
A nickel complex catalyst comprising:
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. Examples of the propylene dimerization catalyst component (A) nickel compound used in the present invention include nickel organic acid salts such as nickel naphthenate, nickel formate, and nickel acetate, nickel chloride, nickel oxalate, nickel nitrate, and the like. Examples thereof include nickel inorganic acid salts and nickel complex compounds such as nickel bisacetylacetonate. Two or more of these nickel compounds can be used.
[0007]
Examples of the trialkylaluminum of the catalyst component (B) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-pentylaluminum, tri-n-hexyl. Aluminum etc. are mentioned. The catalyst component (B) is usually used in an amount of about 2 to 500 moles, preferably about 2 to 100 moles, relative to the catalyst component (A).
[0008]
Examples of the trivalent phosphorus compound of the catalyst component (C) include triisopropylphosphine, tri-t-butylphosphine, tri-sec-butylphosphine, tricyclohexylphosphine, ethyl-di-t-butylphosphine, tri-o- Examples include tolylphosphine and tribenzylphosphine.
The catalyst component (C) is usually used in an amount of about 0.1 to 20 mol times, preferably about 0.5 to 2 mol times with respect to the catalyst component (A).
[0009]
Examples of the fluorinated isopropanol of the catalyst component (D) include 1,1,3,3-tetrafluoroisopropanol, 1,1,1,3,3-pentafluoroisopropanol, 1,1,1,3,3,3. -Hexafluoroisopropanol etc. are mentioned.
Examples of the halogenated phenols represented by the general formula (2) include o-, m-, p-chlorophenol, 2,3-, 2,4-, 2,5-, 2,6-, 3 4,4- and 3,5-dichlorophenol, 2,4,5- and 2,4-6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol and the like.
[0010]
The catalyst component (D) is usually used in an amount of about 0.4 to 20 mol times, preferably about 1 to 10 mol times with respect to the catalyst component (B).
[0011]
Examples of the sulfur component of the catalyst component (E) include aliphatic sulfonic acids such as methanesulfonic acid and ethanesulfonic acid, aromatic sulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid, chlorosulfonic acid, and trifluoromethanesulfonic acid. And sulfonic acids such as halogen-containing sulfonic acids such as dimethyl sulfate and diethyl sulfate. These may be used in combination of two or more.
[0012]
The catalyst component (E) is usually used in an amount of about 0.1 to 10 moles relative to the catalyst component (A).
[0013]
The catalyst is usually prepared in the presence of an inert solvent, and examples thereof include toluene, chlorobenzene, hexane, heptane, dichloroethane and the like.
The order of mixing the catalyst components is not particularly limited, but the catalyst components are preferably mixed in the presence of a conjugated diene such as butadiene or isoprene. In this case, a catalyst having particularly excellent stability can be obtained. The conjugated diene is preferably used in an amount of about 1 to 200 moles relative to the catalyst component (A).
[0014]
The catalyst is usually prepared at a temperature of about -50 to 30 ° C. The propylene dimerization reaction is carried out in an inert solvent such as toluene, chlorobenzene, hexane, heptane, dichloroethane. The concentration of the catalyst component during the reaction is about 10 ⁻⁵ to 10 ⁻¹⁰ mol / l as nickel atoms.
The reaction temperature is usually about -20 to 50 ° C, the reaction time is usually about 30 minutes to 100 hours, and the pressure in the system is usually about 0 to 30 kg / cm ² G.
[0015]
The propylene dimerization reaction solution thus obtained may be rectified as it is to obtain DMB-1, or after the dimerization catalyst is deactivated and removed, DMB-1 distillation may be performed. Examples of the propylene dimerization deactivator include aqueous deactivators such as aqueous ammonia, aqueous amines, aqueous sodium hydroxide, and aqueous potassium hydroxide. When these aqueous quenchers are used, distillation is usually performed after removing the aqueous layer from the oil layer containing DMB-1.
[0016]
In the DMB-1 distillation step, DMB-1 having a purity of 92% or more can be obtained by rectification. That is, in the propylene dimer product mixture, DMB-1 having a low boiling point can be obtained as an initial fraction, and if necessary, the lowest boiling point 4-methylpentene in the propylene dimerization product mixture can be obtained. After distilling 1 from the top of the column, the target DMB-1 can be distilled off (pre-fraction DMB-1).
Of the amount of DMB-1 present in the propylene dimerization solution, the amount of DMB-1 distilled from the top of the column can be arbitrarily changed as desired. In other words, an arbitrary amount of DMB-1 is added to the bottom of the column. Normally, the proportion of DMB-1 distilled from the top of the amount of DMB-1 present in the propylene dimerization solution is 15% to 85%. The remaining DMB-1 may be taken out as it is, or may be taken out from the top of the column by distillation as a post-fraction and separated from a high-boiling product having a propylene trimer or higher (post-fraction DMB-1).
[0017]
The residual DMB-1 or post-cut DMB-1 thus obtained can be converted to DMB-2 by using an isomerization catalyst.
Examples of the isomerization catalyst include aliphatic sulfonic acids such as sulfuric acid, methanesulfonic acid and ethanesulfonic acid, strongly acidic ion exchange resins containing sulfonic acid groups, and heteropolyacids such as silicotungstic acid.
[0018]
The concentration of sulfuric acid used is usually 70% or more, preferably about 90-98%. The amount of sulfuric acid added is about 0.05 to 3 wt% with respect to DMB-1, although it depends on the acid concentration. The amount of sulfonic acids added is also about 0.05 to 3 wt% with respect to DMB-1.
[0019]
When a strongly acidic ion exchange resin containing a sulfonic acid group or a heteropolyacid is used as an isomerization catalyst, it can be isomerized from DMB-1 to DMB-2 in a liquid phase or a gas phase by a batch method or a continuous method. . When the isomerization reaction is carried out by a batch method, the strong acid ion exchange resin and the heteropolyacid catalyst are used in an amount of about 0.1 to 1 wt% with respect to DMB-1. In the case of a continuous reaction, the mixture containing DMB-1 can be circulated through the reaction tube filled with the catalyst at a space velocity of about 1 to 100 / h ⁻¹ for the isomerization reaction.
[0020]
The isomerization reaction can proceed with or without a solvent. When a solvent is used, an inert solvent such as an aromatic hydrocarbon such as benzene or toluene, or an aliphatic hydrocarbon such as hexane or heptane is usually used. These inert solvents are usually used in an amount of about 0.01 to 10 times by weight with respect to DMB-1. Moreover, the reaction liquid after isomerization can also be used as a solvent at the time of isomerization reaction instead of such a solvent. The temperature during the isomerization reaction is usually about -30 to 100 ° C, preferably about 0 to 60 ° C.
[0021]
Thus, DMB-1 is isomerized to DMB-2. When sulfuric acid or sulfonic acid is used as an isomerization catalyst, an alkaline aqueous solution is added to the reaction mixture after isomerization and stirred, and then the acid catalyst is separated by liquid separation. Can be removed.
When an ion exchange resin or heteropolyacid is used as an isomerization catalyst and the isomerization reaction is carried out by a batch method, the reaction mixture is usually filtered to separate the catalyst and the next distillation can be carried out. In this case, the reaction solution can be used for the next distillation as it is.
[0022]
By distilling the reaction mixture containing DMB-2 thus obtained, DMB-2 having a purity of 99% or more can be obtained.
[0023]
【The invention's effect】
The present invention obtains high purity DMB-1 by distilling a propylene dimerization reaction solution obtained by using a propylene dimerization catalyst having excellent propylene dimerization activity and having excellent DMB-1 selectivity. Furthermore, by converting the distillation residue containing DMB-1 into a reaction solution containing DMB-2 using an acid catalyst and distilling it, high-efficiency DMB-1 and DMB-2 are obtained together. A method can be provided.
[0024]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to these Examples.
[Example 1]
(Preparation of propylene dimerization catalyst solution)
The 50 ml Schlenk tube was purged with nitrogen, cooled to 5 ° C., and at the same temperature, 1.35 ml of a toluene solution containing 0.1 mmol of nickel naphthenate, 0.1 mmol of tricyclohexylphosphine and 8 mmol of isoprene were added, and triethylaluminum 1.0 A toluene solution containing mmol was added. Next, 0.1 mmol of trifluoromethanesulfonic acid was added, and 1.5 mmol of 1,1,1,3,3,3-hexafluoroisopropanol was added to obtain a propylene dimerization catalyst solution.
[0025]
[Example 2]
(Propylene dimerization reaction)
The total amount of the catalyst solution and 40 ml of toluene were added to a 1500-ml stainless steel autoclave purged with nitrogen at 10 ° C., and propene was supplied while maintaining a pressure of 3 kg / cm 2 G, followed by reaction at 10 ° C. for 2 hours. After cooling the reaction solution to 5 ° C., unreacted propene was removed from the system. The results of analyzing the reaction mixture by gas chromatography are shown in Table 1 below.
[Table 1]

註)
4M1P: 4-methylpentene-1, 4M2P: cis, trans-4-methylpentene-2, 2M1P: 2-methylpentene-1, 2M2P: 2-methylpentene-2,
Dimer selectivity: Propylene dimerization product ratio in reacted propene x 100
DMB-1 TON: DMB-1 production amount (mmol) / catalyst nickel amount (mmol)
[0026]
[Example 3]
(DMB-1 distillation)
A 1% by weight aqueous 2% sodium hydroxide solution was added to the resulting propylene dimerization reaction solution, stirred at 40 ° C. for 1 h, lowered to 20 ° C., and then separated to obtain 550 g of an oil layer.
550 g of the resulting reaction mixture (containing 320 g of DMB-1) was distilled at normal pressure using a 50-stage rectification column. Distillation was first carried out for a total reflux of 3 hours, and then a 272 g fraction (54-56 ° C.) was withdrawn from the top at a reflux ratio of 30: 1. The purity of DMB-1 in this fraction was 94% (DMB-1 pre-fraction, DMB-1 recovery rate 80%). Further, 81 g of a distillation residue at 56-58 ° C. was obtained from the distillation residue at a reflux ratio of 30: 1.
The purity of DMB-1 in this fraction was 75% (post-DMB-1 fraction, DMB-1 recovery rate 19%).
[0027]
[Example 4]
(DMB-1 → DMB-2 isomerization)
To 80 g of the DMB-1 after-fraction obtained in Example 3, 0.4% by weight of 90% sulfuric acid was added and reacted at 30 ° C. for 3 hours. Subsequently, 50 wt% of 5% aqueous sodium hydroxide solution was added to the reaction solution, stirred at 25 ° C. for 0.5 hour, and then separated to obtain 80 g of an oil layer. As a result of analyzing the reaction solution by gas chromatography, the ratio of DMB-2 to DMB-1 + DMB-2 was 91.0%, and the pure DMB-2 content was 52 g.
[0028]
[Example 5]
A reaction tube (inner diameter 7 mm, length 15 cm) was filled with 2 ml of Amberlyst 15 (strongly acidic ion exchange resin), and then 80 g of DMB-1 tail fraction obtained in the same manner as in Example 3 (purity 75) %) Was circulated at 50 ° C. and 11.2 ml / hr for 8 hours. The obtained reaction solution was 67 g, and the ratio of DMB-2 to DMB-1 + DMB-2 was 91.5%.
The content of DMB-2 was 45.6 g.
[0029]
[Example 6]
A reaction tube (inner diameter 7 mm, length 15 cm) was filled with 0.94 g (2 ml) of silicotungstic acid supported on an activated carbon and calcined, and then 80 g of a DMB-1 after-fraction obtained in the same manner as in Example 3 was obtained. (Purity 75%) was circulated at 20 ° C. and 11.2 ml / hr for 8 hours. The obtained reaction liquid was 67 g, the ratio of DMB-2 to DMB-1 + DMB-2 was 91.2%, and the content of DMB-2 was 45.3 g.
[0030]
[Example 7]
(DMB-2 distillation)
80 g of the reaction solution obtained in Example 4 was distilled at normal pressure using a 30-stage rectification column. Distillation was first carried out for 2 hours in total reflux, and then DMB-1, 4M2P, 2M1P, and 2M2P were distilled from the top of the column under a reflux ratio of 36: 1 and excluded (50-68 ° C. fraction). Next, the reflux ratio was lowered to 10: 1 and 35 g of a 68-73 ° C. fraction was obtained from the top of the column. When this fraction was analyzed by gas chromatography, the purity of DMB-2 was 99.0%.
[0031]
[Example 8]
It carried out based on Example 7 except having used 67 g of the reaction liquid obtained in Example 5. The DMB-2 fraction was 30 g, and the purity of DMB-2 was 99.0%.
[0032]
[Example 9]
It carried out based on Example 7 except having used 67g of the reaction liquid obtained in Example 6. FIG. The DMB-2 fraction was 30 g, and the purity of DMB-2 was 99.0%.

Claims (4)

After dimerizing propylene using the following nickel complex catalyst (propylene dimerization step) and rectifying the resulting reaction solution, 2,3-dimethylbutene-1 was obtained (dimethylbutene-1 distillation step) , Contacting the distillation residue with sulfuric acid, sulfonic acid, or heteropolyacid to isomerize 2,3-dimethylbutene-1 in the distillation residue to 2,3-dimethylbutene-2 (isomerization step), By rectifying the reaction solution, 2,3-dimethylbutene-2 is obtained (dimethylbutene-2 distillation step), which is a combined production of 2,3-dimethylbutene-1 and 2,3-dimethylbutene-2 Method.
(A) At least one nickel compound selected from organic acid salts, inorganic acid salts and complex compounds of nickel, (B) trialkylaluminum, (C) general formula (1)
PR ¹ R ² R ³ (1)
(Wherein R ¹ , R ² and R ³ are the same or different and each represents a phenyl group, an alkyl group, a cycloalkyl group or an aralkyl group which may be substituted with alkyl or alkoxy). A phosphorus compound of (D) fluorinated isopropanol or general formula (2)

(Wherein X _{1 to} X ₅ are the same or different and represent a halogen atom or a hydrogen atom, and at least one is a halogen atom), and (E) sulfonic acids and dialkyl sulfates A nickel complex catalyst comprising at least one sulfur compound selected from: The method according to claim 1, wherein the sulfonic acid used in the isomerization step is a strongly acidic ion exchange resin having a sulfonic acid group . The process according to claim 1, wherein the heteropolyacid used in the isomerization step is silicotungstic acid . The distillation residue is further distilled to obtain a dimethylbutene-1 after-distillation, and the isomerization step and then the dimethylbutene-2 distillation step are carried out by substituting the distillate with the distillation residue Or the method of 3 .