JP3796901B2 - Method for producing cycloalkyl hydroperoxide - Google Patents

Description

（式中、Ｒは炭素数３〜１２のアルキル基又は炭素数５〜８のシクロアルキル基を表し、Ｘは水素原子、炭素数３〜１２のアルキル基、又は炭素数５〜８のシクロアルキル基を表す。）
【０００８】
【発明の実施の形態】
以下に本発明を詳しく説明する。
シクロアルカンとしては、シクロペンタン、シクロヘキサン、シクロヘプタン、シクロオクタン、シクロデカン、シクロドデカン、シクロヘキサデカン等の炭素数５〜１６のシクロアルカンが用いられる。
【０００９】
シクロアルカンに可溶性の遷移金属触媒としては、シクロアルカンに可溶性のコバルト化合物やクロム化合物などが用いられる。遷移金属触媒は単独で使用しても複数で使用しても差し支えなく、その使用量はシクロアルカン１００万重量部に対して金属として０．１〜１０重量部、特に０．３〜５重量部であることが好ましい。
【００１０】
前記のコバルト化合物としては、炭素数６〜２０の脂肪族カルボン酸のコバルト塩（オクチル酸コバルト、ラウリル酸コバルト、パルミチン酸コバルト、ステアリン酸コバルト、リノール酸コバルト等）や、ナフテン酸コバルトや、コバルトアセチルアセトナトなどが挙げられる。 また、前記のクロム化合物としては、炭素数６〜２０の脂肪族カルボン酸のクロム塩（オクチル酸クロム、ラウリル酸クロム、パルミチン酸クロム、ステアリン酸クロム、リノール酸クロム等）や、ナフテン酸クロムや、アセチル酢酸クロムなどが挙げられる。
【００１１】
前記のリン酸エステルとしては、
Ｘが水素原子で、Ｒが炭素数３〜１２のアルキル基であるリン酸モノアルキルエステル（リン酸モノイソプロピル、リン酸モノブチル、リン酸モノ（２−エチルヘキシル、リン酸モノドデシル、リン酸モノベンジル等）や、
Ｘ及びＲが炭素数３〜１２のアルキル基であるリン酸ジアルキルエステル（リン酸ジイソプロピル、リン酸ジブチル、リン酸ジ（２−エチルヘキシル）、リン酸ジデシル、リン酸ジドデシル、リン酸ジベンジル等）や
Ｘが水素原子で、Ｒが炭素数５〜８のシクロアルキル基であるリン酸モノシクロアルキルエステル（リン酸モノシクロペンチル、リン酸モノシクロヘキシル、リン酸モノシクロオクチル等）や、
Ｘ及びＲが炭素数５〜８のシクロアルキル基であるリン酸ジシクロアルキルエステル（リン酸ジシクロペンチル、リン酸ジシクロヘキシル、リン酸ジシクロオクチル等）などが挙げられる。
これらのリン酸エステルの中では、リン酸モノアルキルエステル、リン酸ジアルキルエステルが好ましく、中でもリン酸モノ（２−エチルヘキシル）、リン酸ジ（２−エチルヘキシル）が好ましい。
【００１２】
前記のリン酸エステルは単独で使用しても複数で使用しても差し支えなく、その使用量は、リン酸エステルの酸当量（−ＯＨとして表される）が遷移金属触媒の１原子当たり１０〜３００、好ましくは１５〜１５０、更に好ましくは２０〜１００になる量である。この値〔−ＯＨ／遷移金属原子（当量比）〕が１０以下では、シクロアルキルヒドロペルオキシドの選択率が低下する。
なお、リン酸エステルは、反応前にシクロアルカンに添加してもよく、また、反応途中にそのままもしくはシクロアルカン、シクロアルカノン、シクロアルカノール等に溶解・希釈された形態で反応液に添加してもよい。
【００１３】
本発明では、シクロアルカンにシクロアルカノンを添加して、シクロアルカノンの共存下でシクロアルカンを酸化することが好ましい。シクロアルカノンを添加することにより、反応速度を上げて高選択率でシクロアルキルヒドロペルオキシドを製造することができる。
シクロアルカノンとしては、シクロブタノン、シクロペンタノン、シクロヘキサノン、シクロヘプタノン、シクロオクタノン、シクロデカノン、シクロヘキサデカノン等の炭素数４〜１６のシクロアルカノンが用いられる。シクロアルカノンは単独で使用しても複数で使用しても差し支えなく、その使用量はシクロアルカンに対して０．０１〜１．０重量％、特に０．０５〜０．５重量％であることが好ましい。
【００１４】
分子状酸素は分子状酸素を含有するガスであれば特に限定されるものではなく、例えば、不活性ガス（窒素ガス、アルゴンガス等）で希釈された酸素ガスや純粋な酸素ガスが使用される。
【００１５】
シクロアルカンの酸化は、例えば、ガス導入管、還流冷却器、試料抜き出し管及びリン酸エステル供給管を備えた耐圧ガラスオートクレーブに、所定量のシクロアルカン、シクロアルカノン及び遷移金属触媒を入れ、窒素気流中で所定温度まで昇温した後、分子状酸素含有ガスを導入しながら行われる。このとき、リン酸エステルは前記のように反応前に添加されるか、又は反応途中に加圧挿入ポンプ等を用いて添加される。
なお、酸化反応の反応温度は８０〜２００℃、特に１１０〜１８０℃、更には１３５〜１７５℃であることが好ましく、反応圧は０〜２５ｋｇ／ｃｍ² Ｇ、特に１．５〜１５ｋｇ／ｃｍ² Ｇであることが好ましい。
【００１６】
上記の酸化反応では、シクロアルカンの転化率は、生成したシクロアルキルヒドロペルオキシドが分解を受けて副生物が増加しないような範囲に抑えることが好ましい。例えば、シクロヘキサンでは転化率が１０％を越えないことが好ましく、シクロドデカンでは２０％を越えないことが好ましい。
【００１７】
また、上記の酸化反応では、生成したシクロアルキルヒドロペルオキシドの金属イオン等による分解を抑えるために、ガラスオートクレーブのような反応器内の反応液接触部分がガラス製の反応器を用いるか、又は金属部を全てテフロンコーティングした反応器を用いることが望ましい。その他、金属製の反応器の内部をポリリン酸塩（ピロリン酸ナトリウム、トリポリリン酸ナトリウム等）、エチレンジアミン四酢酸塩、ジピコリン酸、ポリアミノカルボン酸などで処理するか、又はこれらの化合物を反応液に添加することによってシクロアルキルヒドロペルオキシドの分解を抑制してもよい。
【００１８】
生成したシクロアルキルヒドロペルオキシドは、ナフテン酸コバルト等の金属塩の存在下で分解するか〔工業化学雑誌，７３，２８８８（１９７０）〕、又は第８族金属触媒を用いて水素還元することによって（特開昭４８−４０３６号公報）、シクロアルカノンやシクロアルカノールに変換される。
【００１９】
【実施例】
次に、実施例及び比較例を挙げて本発明を具体的に説明する。
なお、シクロアルカン転化率及びシクロアルキルヒドロペルオキシド選択率は次式により求めた。
【００２０】
【数１】

【００２１】
【数２】

【００２２】
実施例１
ガス導入管、還流冷却器、攪拌機、試料抜き出し管及びリン酸エステル供給口を備えた内容積５００ｍｌの耐圧ガラスオートクレーブに、シクロヘキサン２９０ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）を仕込んで、窒素ガスで１０ｋｇ／ｃｍ² Ｇに加圧した後、窒素ガスを流通しながら１６５℃まで昇温した。温度が１６５℃に到達した時点で窒素ガスを空気に切り換えて反応器内を全て空気で置換し、攪拌下（８００ｒｐｍ）、空気を６０Ｌ／ｈｒの流速で供給しながら２分間反応を行った。その後、リン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．０１５ｇ（−ＯＨ／Ｃｏ（当量比）＝３７）を含有するＣｘ溶液１０ｇを加圧定量ポンプで反応液中に２分間で添加して、引き続き４８分間反応を行った（全反応時間：５２分）。
反応後、反応液のガスクロマトグラフィー分析と化学分析を行ったところ、シクロヘキサン（以下、Ｃｘと称する）転化率は３．８％で、シクロアルキルヒドロペルオキシド（以下、ＣＨＰと称する）選択率は６３％であった。
【００２３】
比較例１
実施例１において、オクチル酸コバルト濃度をコバルト金属として１．０重量ｐｐｍに変え、リン酸エステル混合物含有溶液をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．００６ｇ（−ＯＨ／Ｃｏ（当量比）＝７）を含有するＣｘ溶液１０ｇに代えて４４分間反応を行ったほかは、実施例１と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．９％で、ＣＨＰ選択率は３８％であった。
【００２４】
実施例２
実施例１と同様の耐圧ガラスオートクレーブに、Ｃｘ３００ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）、及びリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．００６ｇ（−ＯＨ／Ｃｏ（当量比）＝１５）を仕込んで窒素ガスで１０ｋｇ／ｃｍ² Ｇに加圧した後、窒素ガスを流通しながら１６５℃まで昇温した。温度が１６５℃に到達した時点で窒素ガスを空気に切り換えて反応器内を全て空気で置換し、攪拌下（８００ｒｐｍ）、空気を６０Ｌ／ｈｒの流速で供給しながら６１分間反応を行った。
反応後、実施例１と同様に分析を行ったところ、Ｃｘ転化率は３．８％で、ＣＨＰ選択率は６１％であった。
【００２５】
実施例３
実施例２において、リン酸エステル混合物をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．０１５ｇ（−ＯＨ／Ｃｏ（当量比）＝３７）に代えて、５５分間反応を行ったほかは、実施例２と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．５％で、ＣＨＰ選択率は６３％であった。
【００２６】
比較例２
実施例２において、リン酸エステル混合物をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．００３ｇ（−ＯＨ／Ｃｏ（当量比）＝７）に代えて、５１分間反応を行ったほかは、実施例２と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．９％で、ＣＨＰ選択率は４８％であった。
【００２７】
比較例３
実施例２において、オクチル酸コバルト量をコバルト金属として１．０重量ｐｐｍに変え、リン酸エステル混合物をリン酸ジ（２−エチルヘキシル）０．０１ｇ（−ＯＨ／Ｃｏ（当量比）＝６）に代えて、５４分間反応を行ったほかは、実施例２と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．８％で、ＣＨＰ選択率は４３％であった。
実施例１〜３及び比較例１〜３の結果を表１に示す。
【００２８】
【表１】

【００２９】
実施例４
実施例１において、Ｃｘ２９０ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）を仕込み、更にシクロヘキサノン０．６ｇを仕込んだほかは、実施例１と同様に反応（全反応時間：３７分）と分析を行った。
その結果、Ｃｘ転化率は３．８％で、ＣＨＰ選択率は５８％であった。
【００３０】
実施例５
実施例１において、Ｃｘ２９０ｇとオクチル酸コバルト（コバルト金属として１．０重量ｐｐｍ）を仕込み、更にシクロペンタノン０．６ｇを仕込み、リン酸エステル混合物含有溶液をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．０６ｇ（−ＯＨ／Ｃｏ（当量比）＝７４）を含有するＣｘ溶液１０ｇに代えたほかは、実施例１と同様に反応（全反応時間：４０分）と分析を行った。
その結果、Ｃｘ転化率は４．１％で、ＣＨＰ選択率は６０％であった。
【００３１】
実施例６
実施例２において、Ｃｘ３００ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）を仕込み、更にシクロヘキサノン０．３ｇを仕込み、リン酸エステル混合物をリン酸ジ（２−エチルヘキシル）０．０３ｇ（−ＯＨ／Ｃｏ（当量比）＝３７）に代えて４５分間反応を行ったほかは、実施例２と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．７％で、ＣＨＰ選択率は６１％であった。
【００３２】
実施例７
実施例２において、Ｃｘ３００ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）を仕込み、更にシクロヘキサノン０．９ｇとピロリン酸ソーダ１０水和物０．３ｇを仕込み、リン酸エステル混合物をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．０１５ｇ（−ＯＨ／Ｃｏ（当量比）＝３７）に代えて４２分間反応を行ったほかは、実施例２と同様に反応と分析を行った。
その結果、Ｃｘ転化率は３．８％で、ＣＨＰ選択率は６３％であった。
実施例４〜７の結果を表２に示す。
【００３３】
【表２】

【００３４】
実施例８
実施例１と同様の耐圧ガラスオートクレーブに、シクロドデカン１５０ｇとオクチル酸コバルト（コバルト金属として０．５重量ｐｐｍ）、及びリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．００７５ｇ（−ＯＨ／Ｃｏ（当量比）＝３７）を仕込んで窒素ガスで５ｋｇ／ｃｍ² Ｇに加圧した後、窒素ガスを流通しながら１６０℃まで昇温した。温度が１６０℃に到達した時点で窒素ガスを空気に切り換えて反応器内を全て空気で置換し、攪拌下（８００ｒｐｍ）、空気を４０Ｌ／ｈｒの流速で供給しながら７５分間反応を行った。
反応後、反応液のガスクロマトグラフィー分析と化学分析を行ったところ、シクロドデカン（以下、ＣＤＡＮと称する）転化率は１４．５％で、シクロドデシルヒドロペルオキシド（以下、ＣＤＨＰと称する）選択率は６８％であった。
【００３５】
比較例４
実施例８において、リン酸エステル混合物をリン酸モノ（２−エチルヘキシル）とリン酸ジ（２−エチルヘキシル）の重量比が１：１であるリン酸エステル混合物０．０００８ｇ（−ＯＨ／Ｃｏ（当量比）＝４）に代えて、５０分間反応を行ったほかは、実施例８と同様に反応と分析を行った。
その結果、ＣＤＡＮ転化率は１２．４％で、ＣＤＨＰ選択率は３２％であった。実施例８及び比較例４の結果を表３に示す。
【００３６】
【表３】

【００３７】
【発明の効果】
本発明により、シクロアルカンを分子状酸素で酸化してシクロアルキルヒドロペルオキシドを高反応速度及び高選択率で製造することができる。この結果、本発明の反応液中に蓄積されたシクロアルキルヒドロペルオキシドを公知の方法で分解することにより、シクロアルカノン及びシクロアルカノールを高い收率で製造することが可能になる。[0001]
[Industrial application fields]
The present invention relates to a method for producing cycloalkyl hydroperoxide with high yield by oxidizing cycloalkane with molecular oxygen. Cycloalkyl hydroperoxides are useful compounds as intermediates for the production of cycloalkanols and cycloalkanones and as peroxides.
[0002]
[Prior art]
The industrial oxidation of cycloalkane is usually carried out in the presence of a transition metal catalyst such as cobalt naphthenate. In this reaction, the produced cycloalkyl hydroperoxide is decomposed by the catalyst during the reaction, so that the accumulation amount is small, and the main products are the corresponding alcohol and ketone. For example, in the air oxidation of cyclohexane, the cyclohexane conversion is 3 to 5%, and the total selectivity of cyclohexanol and cyclohexanone is 70 to 80%.
[0003]
Thus, since the transition metal catalyst serves as a catalyst for promoting the decomposition of peroxides such as cycloalkyl hydroperoxide, the reaction for producing cycloalkyl hydroperoxide by oxidizing cycloalkane is carried out in the absence of the transition metal catalyst. . However, the non-catalytic oxidation of cycloalkane has a problem that the oxidation reaction rate is extremely slow, and the cycloalkyl hydroperoxide selectivity decreases when oxidation is performed at a high temperature in order to increase the reaction rate.
[0004]
For this reason, methods for increasing both the rate of the oxidation reaction and the selectivity of the cycloalkyl hydroperoxide have been studied.
For example, a method in which cyclohexane is oxidized with oxygen in the presence of a soluble cobalt compound catalyst and a phosphate ester that gives an acid equivalent of about 3 to 8 per cobalt atom (JP-A-612020359), in the presence of borophosphoric acid In addition, a method of oxidizing cyclohexane with molecular oxygen (Japanese Patent Publication No. 44-27022) is known. However, none of these methods can be said to be industrially satisfactory, and further improvements in reaction rate and selectivity are desired.
[0005]
[Problems to be solved by the invention]
The present invention provides an industrially suitable method for producing a cycloalkyl hydroperoxide, which can oxidize a cycloalkane with molecular oxygen to produce a cycloalkyl hydroperoxide with high reaction rate and high selectivity. Is an issue.
[0006]
[Means for Solving the Problems]
An object of the present invention is to oxidize a cycloalkane with molecular oxygen in the presence of a transition metal catalyst soluble in cycloalkane and a phosphate ester having a structure of the following formula having an acid equivalent of 10 to 300 times per transition metal atom. This is achieved by a method for producing a cycloalkyl hydroperoxide.
[0007]
[Chemical 2]

(In the formula, R represents an alkyl group having 3 to 12 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, and X represents a hydrogen atom, an alkyl group having 3 to 12 carbon atoms, or a cycloalkyl having 5 to 8 carbon atoms. Represents a group.)
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
As the cycloalkane, a cycloalkane having 5 to 16 carbon atoms such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, and cyclohexadecane is used.
[0009]
As the transition metal catalyst soluble in cycloalkane, a cobalt compound or a chromium compound soluble in cycloalkane is used. The transition metal catalyst may be used alone or in combination, and the amount used is 0.1 to 10 parts by weight, particularly 0.3 to 5 parts by weight as a metal with respect to 1 million parts by weight of cycloalkane. It is preferable that
[0010]
Examples of the cobalt compound include cobalt salts of aliphatic carboxylic acids having 6 to 20 carbon atoms (such as cobalt octylate, cobalt laurate, cobalt palmitate, cobalt stearate, and cobalt linoleate), cobalt naphthenate, and cobalt. Examples include acetylacetonate. Examples of the chromium compound include chromium salts of aliphatic carboxylic acids having 6 to 20 carbon atoms (chromium octylate, chromium laurate, chromium palmitate, chromium stearate, chromium linoleate, etc.), chromium naphthenate, , Chromium acetyl acetate and the like.
[0011]
As the phosphoric acid ester,
Phosphoric acid monoalkyl ester wherein X is a hydrogen atom and R is an alkyl group having 3 to 12 carbon atoms (monoisopropyl phosphate, monobutyl phosphate, mono (2-ethylhexyl, monododecyl phosphate, monobenzyl phosphate) Etc.)
Dialkyl phosphate X and R is an alkyl group having 3 to 12 carbon atoms (diisopropyl phosphate, dibutyl phosphate, phosphoric acid di (2-ethylhexyl), didecyl phosphate, didodecyl phosphate, dibenzyl phosphate, etc.) Ya Phosphoric acid monocycloalkyl ester wherein X is a hydrogen atom and R is a cycloalkyl group having 5 to 8 carbon atoms (monocyclopentyl phosphate, monocyclohexyl phosphate, monocyclooctyl phosphate, etc.),
Examples include phosphoric acid dicycloalkyl esters (dicyclopentyl phosphate, dicyclohexyl phosphate, dicyclooctyl phosphate, etc.) in which X and R are cycloalkyl groups having 5 to 8 carbon atoms.
Among these phosphate esters, monoalkyl phosphates and dialkyl phosphates are preferred, and mono (2-ethylhexyl) phosphate and di (2-ethylhexyl) phosphate are particularly preferred.
[0012]
The above phosphoric acid esters may be used alone or in plural, and the amount used is such that the acid equivalent of the phosphoric acid ester (expressed as —OH) is 10 to 10 per atom of the transition metal catalyst. The amount is 300, preferably 15 to 150, more preferably 20 to 100. When this value [—OH / transition metal atom (equivalent ratio)] is 10 or less, the selectivity of cycloalkyl hydroperoxide is lowered.
The phosphate ester may be added to the cycloalkane before the reaction, or added to the reaction solution as it is in the middle of the reaction or in a form dissolved or diluted in cycloalkane, cycloalkanone, cycloalkanol or the like. Also good.
[0013]
In the present invention, it is preferable to add cycloalkanone to cycloalkane and oxidize cycloalkane in the presence of cycloalkanone. By adding cycloalkanone, the reaction rate can be increased and cycloalkyl hydroperoxide can be produced with high selectivity.
As the cycloalkanone, a cycloalkanone having 4 to 16 carbon atoms such as cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclodecanone, cyclohexadecanone, or the like is used. The cycloalkanone may be used alone or in combination, and the amount used is 0.01 to 1.0% by weight, particularly 0.05 to 0.5% by weight, based on the cycloalkane. It is preferable.
[0014]
The molecular oxygen is not particularly limited as long as it is a gas containing molecular oxygen. For example, oxygen gas diluted with an inert gas (nitrogen gas, argon gas, etc.) or pure oxygen gas is used. .
[0015]
For the oxidation of cycloalkane, for example, a predetermined amount of cycloalkane, cycloalkanone and transition metal catalyst are put into a pressure-resistant glass autoclave equipped with a gas introduction tube, a reflux condenser, a sample extraction tube and a phosphate ester supply tube, and nitrogen is added. The temperature is raised to a predetermined temperature in an air stream, and then introduced while introducing a molecular oxygen-containing gas. At this time, the phosphate ester is added before the reaction as described above, or is added using a pressure insertion pump or the like during the reaction.
The reaction temperature of the oxidation reaction is preferably 80 to 200 ° C., particularly 110 to 180 ° C., more preferably 135 to 175 ° C., and the reaction pressure is 0 to 25 kg / cm ² G, particularly 1.5 to 15 kg / cm. ² G is preferred.
[0016]
In the above oxidation reaction, the conversion rate of cycloalkane is preferably suppressed to a range in which the produced cycloalkyl hydroperoxide is decomposed and by-products do not increase. For example, it is preferable that the conversion rate does not exceed 10% for cyclohexane and 20% for cyclododecane.
[0017]
In the above oxidation reaction, in order to suppress decomposition of the produced cycloalkyl hydroperoxide by metal ions or the like, the reaction liquid contact portion in the reactor such as a glass autoclave uses a glass reactor, or a metal It is desirable to use a reactor in which all parts are coated with Teflon. In addition, the inside of the metal reactor is treated with polyphosphate (sodium pyrophosphate, sodium tripolyphosphate, etc.), ethylenediaminetetraacetate, dipicolinic acid, polyaminocarboxylic acid, etc., or these compounds are added to the reaction solution By doing so, decomposition of the cycloalkyl hydroperoxide may be suppressed.
[0018]
The produced cycloalkyl hydroperoxide is decomposed in the presence of a metal salt such as cobalt naphthenate [Industrial Chemical Journal, 73, 2888 (1970)], or by hydrogen reduction using a Group 8 metal catalyst ( JP, 48-4036), and converted into cycloalkanone or cycloalkanol.
[0019]
【Example】
Next, the present invention will be specifically described with reference to examples and comparative examples.
The cycloalkane conversion rate and the cycloalkyl hydroperoxide selectivity were determined by the following formulas.
[0020]
[Expression 1]

[0021]
[Expression 2]

[0022]
Example 1
290 g of cyclohexane and cobalt octylate (0.5 ppm by weight as cobalt metal) were charged in a pressure-resistant glass autoclave having an internal volume of 500 ml equipped with a gas introduction tube, reflux condenser, stirrer, sample extraction tube and phosphate ester supply port. After pressurizing to 10 kg / cm ² G with nitrogen gas, the temperature was raised to 165 ° C. while flowing nitrogen gas. When the temperature reached 165 ° C., the nitrogen gas was switched to air and the entire reactor was replaced with air, and the reaction was carried out for 2 minutes while stirring (800 rpm) and supplying air at a flow rate of 60 L / hr. Thereafter, 0.015 g (-OH / Co (equivalent ratio) = 37) of a phosphate ester mixture in which the weight ratio of mono (2-ethylhexyl) phosphate to di (2-ethylhexyl) phosphate is 1: 1 is contained. 10 g of Cx solution was added to the reaction solution with a pressurized metering pump in 2 minutes, and the reaction was continued for 48 minutes (total reaction time: 52 minutes).
After the reaction, the reaction mixture was subjected to gas chromatography analysis and chemical analysis. As a result, the conversion of cyclohexane (hereinafter referred to as Cx) was 3.8%, and the selectivity for cycloalkyl hydroperoxide (hereinafter referred to as CHP) was 63. %Met.
[0023]
Comparative Example 1
In Example 1, the cobalt octylate concentration was changed to 1.0 ppm by weight as cobalt metal, and the phosphate ester mixture-containing solution had a weight ratio of mono (2-ethylhexyl) phosphate to di (2-ethylhexyl) phosphate of 1 : Reaction and analysis in the same manner as in Example 1 except that the reaction was performed for 44 minutes instead of 10 g of the Cx solution containing 0.006 g of the phosphate ester mixture (-OH / Co (equivalent ratio) = 7). Went.
As a result, the Cx conversion rate was 3.9% and the CHP selectivity was 38%.
[0024]
Example 2
In a pressure-resistant glass autoclave similar to that in Example 1, the weight ratio of Cx 300 g and cobalt octylate (0.5 ppm by weight as cobalt metal) and mono (2-ethylhexyl) phosphate and di (2-ethylhexyl) phosphate is 1. 1: 0.006 g of phosphoric ester mixture (-OH / Co (equivalent ratio) = 15) was charged to 10 kg / cm ² G with nitrogen gas, and then increased to 165 ° C. while flowing nitrogen gas. Warm up. When the temperature reached 165 ° C., the nitrogen gas was switched to air and the entire reactor was replaced with air, and the reaction was carried out for 61 minutes while stirring (800 rpm) and supplying air at a flow rate of 60 L / hr.
After the reaction, analysis was conducted in the same manner as in Example 1. As a result, the Cx conversion rate was 3.8% and the CHP selectivity was 61%.
[0025]
Example 3
In Example 2, 0.015 g (-OH / Co (equivalent to -OH / Co (equivalent weight)) of a phosphate ester mixture in which the weight ratio of mono (2-ethylhexyl) phosphate to di (2-ethylhexyl) phosphate was 1: 1. The reaction and analysis were performed in the same manner as in Example 2 except that the reaction was performed for 55 minutes instead of (ratio) = 37).
As a result, Cx conversion was 3.5% and CHP selectivity was 63%.
[0026]
Comparative Example 2
In Example 2, 0.003 g (-OH / Co (equivalent to -OH / Co (equivalent weight)) of a phosphate ester mixture in which the weight ratio of mono (2-ethylhexyl) phosphate to di (2-ethylhexyl) phosphate is 1: 1. The reaction and analysis were performed in the same manner as in Example 2 except that the reaction was performed for 51 minutes instead of (ratio) = 7).
As a result, the Cx conversion rate was 3.9% and the CHP selectivity was 48%.
[0027]
Comparative Example 3
In Example 2, the amount of cobalt octylate was changed to 1.0 ppm by weight as cobalt metal, and the phosphate ester mixture was changed to 0.01 g of di (2-ethylhexyl) phosphate (—OH / Co (equivalent ratio) = 6). Instead, the reaction and analysis were performed in the same manner as in Example 2 except that the reaction was performed for 54 minutes.
As a result, the Cx conversion rate was 3.8% and the CHP selectivity was 43%.
Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 3.
[0028]
[Table 1]

[0029]
Example 4
In Example 1, the reaction (total reaction time: 37 minutes) was performed in the same manner as in Example 1 except that 290 g of Cx and cobalt octylate (0.5 ppm by weight as cobalt metal) and 0.6 g of cyclohexanone were further charged. Analysis was carried out.
As a result, the Cx conversion rate was 3.8% and the CHP selectivity was 58%.
[0030]
Example 5
In Example 1, 290 g of Cx and cobalt octylate (1.0 ppm by weight as cobalt metal) were charged, 0.6 g of cyclopentanone was further charged, and the phosphate ester mixture-containing solution was mixed with mono (2-ethylhexyl) phosphate and phosphorus. Example 1 except that 10 g of a Cx solution containing 0.06 g (—OH / Co (equivalent ratio) = 74) of a phosphate ester mixture in which the weight ratio of di (2-ethylhexyl) acid was 1: 1 was used. The reaction (total reaction time: 40 minutes) and analysis were carried out in the same manner as above.
As a result, the Cx conversion rate was 4.1%, and the CHP selectivity was 60%.
[0031]
Example 6
In Example 2, 300 g of Cx and cobalt octylate (0.5 ppm by weight as cobalt metal) were charged, 0.3 g of cyclohexanone was further charged, and 0.03 g (-OH) of di (2-ethylhexyl) phosphate was added to the phosphate ester mixture. The reaction and analysis were performed in the same manner as in Example 2 except that the reaction was performed for 45 minutes instead of / Co (equivalent ratio) = 37).
As a result, the Cx conversion rate was 3.7%, and the CHP selectivity was 61%.
[0032]
Example 7
In Example 2, 300 g of Cx and cobalt octylate (0.5 ppm by weight as cobalt metal) were added, 0.9 g of cyclohexanone and 0.3 g of sodium pyrophosphate decahydrate were added, and the phosphate ester mixture was added to monophosphate. The reaction was carried out for 42 minutes instead of 0.015 g (—OH / Co (equivalent ratio) = 37) of a phosphate ester mixture in which the weight ratio of (2-ethylhexyl) and di (2-ethylhexyl) phosphate was 1: 1. Otherwise, the reaction and analysis were carried out in the same manner as in Example 2.
As a result, the Cx conversion rate was 3.8% and the CHP selectivity was 63%.
The results of Examples 4-7 are shown in Table 2.
[0033]
[Table 2]

[0034]
Example 8
In a pressure-resistant glass autoclave similar to that in Example 1, 150 g of cyclododecane and cobalt octylate (0.5 ppm by weight as cobalt metal), and a weight ratio of mono (2-ethylhexyl) phosphate and di (2-ethylhexyl) phosphate Was charged with 0.0075 g (-OH / Co (equivalent ratio) = 37) of a phosphoric ester mixture having a ratio of 1: 1, and pressurized to 5 kg / cm ² G with nitrogen gas. The temperature was raised to. When the temperature reached 160 ° C., the nitrogen gas was switched to air and the inside of the reactor was completely replaced with air, and the reaction was carried out for 75 minutes while stirring (800 rpm) and supplying air at a flow rate of 40 L / hr.
After the reaction, gas chromatographic analysis and chemical analysis of the reaction solution were performed. As a result, the conversion of cyclododecane (hereinafter referred to as CDAN) was 14.5%, and the selectivity for cyclododecyl hydroperoxide (hereinafter referred to as CDHP) was It was 68%.
[0035]
Comparative Example 4
In Example 8, 0.0008 g (-OH / Co (equivalent to -OH / Co equivalent) of a phosphate ester mixture in which the weight ratio of mono (2-ethylhexyl) phosphate to di (2-ethylhexyl) phosphate was 1: 1. The reaction and analysis were performed in the same manner as in Example 8 except that the reaction was performed for 50 minutes instead of (ratio) = 4).
As a result, the CDAN conversion rate was 12.4% and the CDHP selectivity was 32%. The results of Example 8 and Comparative Example 4 are shown in Table 3.
[0036]
[Table 3]

[0037]
【The invention's effect】
According to the present invention, cycloalkane can be oxidized with molecular oxygen to produce cycloalkyl hydroperoxide with high reaction rate and high selectivity. As a result, cycloalkanone and cycloalkanol can be produced at a high yield by decomposing cycloalkyl hydroperoxide accumulated in the reaction solution of the present invention by a known method.

Claims (3)

In the presence of a cobalt salt of an aliphatic carboxylic acid having 6 to 20 carbon atoms that is soluble in cycloalkane , or a phosphate ester having a structure of the following formula with 10 to 300 times the acid equivalent per cobalt atom and cobalt naphthenate : A method for producing a cycloalkyl hydroperoxide, comprising oxidizing an alkane with molecular oxygen.
[Chemical 1]

(In the formula, R represents an alkyl group having 3 to 12 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, and X represents a hydrogen atom, an alkyl group having 3 to 12 carbon atoms, or a cycloalkyl having 5 to 8 carbon atoms. Represents a group.) The method for producing a cycloalkyl hydroperoxide according to claim 1, wherein the cobalt salt of an aliphatic carboxylic acid having 6 to 20 carbon atoms is cobalt octylate . The method for producing a cycloalkyl hydroperoxide according to claim 1, wherein the cycloalkane is oxidized with molecular oxygen in the presence of cycloalkanone.