JPH1045676A - Production of dialkyl carbonate - Google Patents
Production of dialkyl carbonateInfo
- Publication number
- JPH1045676A JPH1045676A JP8204681A JP20468196A JPH1045676A JP H1045676 A JPH1045676 A JP H1045676A JP 8204681 A JP8204681 A JP 8204681A JP 20468196 A JP20468196 A JP 20468196A JP H1045676 A JPH1045676 A JP H1045676A
- Authority
- JP
- Japan
- Prior art keywords
- reaction
- dialkyl
- oxide
- oxalate
- dialkyl carbonate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、医薬、農薬等の有
機合成原料として、またポリカーボネートやウレタン等
の製造原料として有用な炭酸ジアルキルを製造する方法
に関する。The present invention relates to a method for producing a dialkyl carbonate useful as a raw material for organic synthesis of medicines, agricultural chemicals and the like, and also as a raw material for producing polycarbonate and urethane.
【０００２】[0002]
【従来の技術】シュウ酸ジアルキルを脱カルボニル反応
させて炭酸ジアルキルを製造する方法としては、シュウ
酸ジアルキルをアルコラート触媒の存在下に５０〜１５
０℃に液相で加熱する方法が知られている（米国特許４
５４４５０７号）。しかしながら、この方法は液相均一
反応であるために生成物及び触媒の分離・回収が煩雑に
なり、工業的には必ずしも有利な方法ではない。2. Description of the Related Art As a method for producing a dialkyl carbonate by subjecting a dialkyl oxalate to a decarbonylation reaction, a dialkyl oxalate is prepared in the presence of an alcoholate catalyst in the range of 50 to 15 to 50 to 15%.
A method of heating to 0 ° C. in a liquid phase is known (US Pat.
No. 544507). However, since this method is a liquid phase homogeneous reaction, separation and recovery of a product and a catalyst are complicated, and this is not necessarily an industrially advantageous method.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、シュウ酸ジ
アルキルを脱カルボニル反応させて炭酸ジアルキルを製
造する方法において、生成物及び触媒の分離・回収が容
易な方法（即ち、気相反応）によって、炭酸ジアルキル
を容易に製造することを課題とする。SUMMARY OF THE INVENTION The present invention relates to a method for producing a dialkyl carbonate by subjecting a dialkyl oxalate to a decarbonylation reaction, wherein the product and the catalyst can be easily separated and recovered (ie, by a gas phase reaction). It is an object to easily produce dialkyl carbonate.
【０００４】[0004]
【課題を解決するための手段】本発明の課題は、シュウ
酸ジアルキルを、比表面積が５〜３０ｍ2 ／ｇであるII
Ａ族又はIII Ａ族金属の酸化物の存在下、気相で脱カル
ボニル反応させることを特徴とする炭酸ジアルキルの製
造方法によって達成される。An object of the present invention is to provide dialkyl oxalate having a specific surface area of 5 to 30 m 2 / g.
This is achieved by a method for producing a dialkyl carbonate, which comprises performing a decarbonylation reaction in the gas phase in the presence of an oxide of a Group A or Group IIIA metal.
【０００５】[0005]
【発明の実施の形態】本発明では、炭酸ジアルキルは次
式で示されるシュウ酸ジアルキルの脱カルボニル反応に
よって生成する。DETAILED DESCRIPTION OF THE INVENTION In the present invention, dialkyl carbonate is formed by a decarbonylation reaction of a dialkyl oxalate represented by the following formula.
【０００６】[0006]
【化１】 （式中、Ｒはアルキル基を示す。）Embedded image (In the formula, R represents an alkyl group.)
【０００７】前記のアルキル基としては、メチル基、エ
チル基、ｎ−プロピル基、ｎ−ブチル基、ｎ−アミル基
等の炭素数１〜６のアルキル基が挙げられる。即ち、シ
ュウ酸ジアルキルとしては、シュウ酸ジメチル、シュウ
酸ジエチル、シュウ酸ジｎ−プロピル、シュウ酸ジｎ−
ブチル、シュウ酸ジｎ−アミル等が使用される。シュウ
酸ジアルキルの中では、シュウ酸ジメチル、シュウ酸ジ
エチルが特に好ましい。[0007] Examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-amyl group. That is, examples of the dialkyl oxalate include dimethyl oxalate, diethyl oxalate, di-n-propyl oxalate, and di-n-oxalate.
Butyl, di-n-amyl oxalate and the like are used. Among the dialkyl oxalates, dimethyl oxalate and diethyl oxalate are particularly preferred.
【０００８】本発明では、触媒としてIIＡ族又はIII Ａ
族金属の酸化物を存在させて、前記の脱カルボニル反応
が行われる。IIＡ族金属の酸化物としては、マグネシ
ア、酸化カルシウム、酸化バリウム等が用いられ、III
Ａ族金属の酸化物としては、アルミナ、酸化インジウム
等が使用されるが、中でもアルミナ、マグネシアが特に
好ましい。In the present invention, the catalyst is a group IIA or IIIA
The decarbonylation reaction is performed in the presence of an oxide of a group metal. Magnesia, calcium oxide, barium oxide and the like are used as the oxides of Group IIA metals.
As the oxide of the Group A metal, alumina, indium oxide and the like are used, and among them, alumina and magnesia are particularly preferable.
【０００９】また、この金属酸化物の比表面積は５〜３
０ｍ2 ／ｇであることが好ましい。比表面積は金属酸化
物を調製する段階で制御可能であるが、市販の金属酸化
物を焼成する際に制御するのが簡便である。金属酸化物
の焼成は空気中又は窒素ガス中で通常８００〜１４００
℃で行われる。なお、比表面積は公知のＢＥＴ法により
測定される。The specific surface area of the metal oxide is 5 to 3
It is preferably 0 m 2 / g. Although the specific surface area can be controlled at the stage of preparing the metal oxide, it is convenient to control it when firing a commercially available metal oxide. The calcination of the metal oxide is usually carried out in air or nitrogen gas at 800 to 1400.
Performed at ° C. The specific surface area is measured by a known BET method.
【００１０】前記の金属酸化物は、粉末、粒状、破砕
状、ビーズ状もしくは成型体で使用される。その形状は
特に限定されるものではないが、通常、粉末の場合は２
０〜１００μｍφ程度のもの、粒状、破砕状、ビーズ状
の場合は４〜２００メッシュ程度のもの、成型体の場合
は長さ０．５〜１０ｍｍ程度のものが使用される。The above-mentioned metal oxide is used in the form of powder, granules, crushed particles, beads or molded products. The shape is not particularly limited, but usually 2 in the case of powder.
A particle having a diameter of about 0 to 100 μm, a particle, a crushed or a bead having a length of about 4 to 200 mesh, and a molded article having a length of about 0.5 to 10 mm are used.
【００１１】シュウ酸ジアルキルの脱カルボニル反応
は、触媒として前記の金属酸化物を存在させてシュウ酸
ジアルキルを気相で加熱することによって行われる。こ
のとき、前記反応式に従って、シュウ酸ジアルキルから
炭酸ジアルキルが生成すると共に一酸化炭素が発生す
る。反応は気相連続式で行うのが工業的に有利である。
触媒は反応系で固定床、移動床のいずれの形態でも使用
されうるが、通常は固定床で使用される。また、反応器
としては、例えばステンレス鋼製や石英製の反応管が使
用される。The decarbonylation of dialkyl oxalate is carried out by heating the dialkyl oxalate in the gas phase in the presence of the above-mentioned metal oxide as a catalyst. At this time, according to the above reaction formula, dialkyl carbonate is generated from dialkyl oxalate and carbon monoxide is generated. It is industrially advantageous to carry out the reaction in a gas phase continuous system.
The catalyst may be used in a fixed bed or a moving bed in the reaction system, but is usually used in a fixed bed. As the reactor, for example, a reaction tube made of stainless steel or quartz is used.
【００１２】気相連続式で反応を行う場合、脱カルボニ
ル反応は、前記触媒を充填した反応器に、シュウ酸ジア
ルキルや不活性ガス（窒素ガス等）及び必要に応じてア
ルコールを含有する原料ガスを通常１００〜５０００ｈ
ｒ-1、好ましくは４００〜３０００ｈｒ-1の空間速度で
供給することによって行われる。このとき、反応温度は
通常１７０〜４５０℃、好ましくは２００〜４００℃で
あり、反応圧力は気相で反応を行うことができれば特に
制限されないが、通常は常圧もしくは減圧下である。When the reaction is carried out in a gas phase continuous system, the decarbonylation reaction is carried out by placing a raw material gas containing dialkyl oxalate, an inert gas (such as nitrogen gas) and, if necessary, an alcohol in a reactor filled with the catalyst. Is usually 100 ~ 5000h
It is carried out by feeding at a space velocity of r -1 , preferably 400 to 3000 hr -1 . At this time, the reaction temperature is usually 170 to 450 ° C, preferably 200 to 400 ° C, and the reaction pressure is not particularly limited as long as the reaction can be performed in a gas phase, but is usually normal pressure or reduced pressure.
【００１３】原料ガスにシュウ酸ジアルキルを含有させ
る操作は、例えば、シュウ酸ジアルキル濃度が１０〜４
０重量％、好ましくは１５〜３０重量％のシュウ酸ジア
ルキルのアルコール溶液を気化器又は反応器中の気化層
等で気化させて、窒素ガス等の不活性ガスに同伴させる
ことによって行われる。また、シュウ酸ジアルキルをそ
のまま気化器又は反応器中の気化層等で気化させて、同
様に原料ガスにシュウ酸ジアルキルを含有させることも
できる。反応後、生成した炭酸ジアルキルは、反応管か
ら導出される反応ガスを凝縮させて、得られる反応液か
ら蒸留等により分離精製される。[0013] The operation of containing a dialkyl oxalate in the raw material gas is performed, for example, when the dialkyl oxalate concentration is 10 to 4%.
It is carried out by vaporizing an alcohol solution of 0% by weight, preferably 15 to 30% by weight of a dialkyl oxalate in a vaporizer or a vaporization layer in a reactor and accompanying an inert gas such as nitrogen gas. Further, the dialkyl oxalate can be directly vaporized in a vaporizer or a vaporization layer in a reactor, and the dialkyl oxalate can be similarly contained in the raw material gas. After the reaction, the generated dialkyl carbonate is obtained by condensing a reaction gas derived from a reaction tube, and is separated and purified from the obtained reaction solution by distillation or the like.
【００１４】[0014]
【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、シュウ酸ジアルキルの転化率及
び炭酸ジアルキルの選択率は次式により求めた。Next, the present invention will be described specifically with reference to examples and comparative examples. The conversion of dialkyl oxalate and the selectivity of dialkyl carbonate were determined by the following formula.
【００１５】[0015]
【数１】 (Equation 1)
【００１６】[0016]
【数２】 (Equation 2)
【００１７】実施例１ 市販の球状アルミナ（ＫＨＳ−２４；住友化学製）を空
気中、１３００℃で３時間焼成して、比表面積が５ｍ2
／ｇの球状アルミナを得た。得られた球状アルミナ２５
ｍｌを、内径２５ｍｍ、長さ３５０ｍｍの石英製反応管
に充填した後、反応管を垂直に固定し、触媒層の温度を
３５０℃に加熱制御した。次いで、この反応管の上部か
ら、シュウ酸ジメチル濃度が１５重量％のシュウ酸ジメ
チルのメタノール溶液を１２．１ｇ／ｈｒで供給し、こ
れを触媒層上部の気化層で気化させて、窒素ガスと共に
触媒層に供給して反応を行った。このときのシュウ酸ジ
メチル、メタノール及び窒素ガスを含む原料ガスの空間
速度は１０２２ｈｒ-1であった。反応後、氷冷トラップ
に補集して得られた反応液をガスクロマトグラフィーに
より分析したところ、シュウ酸ジメチルの転化率は５
０．０％で、炭酸ジメチルの選択率は３７．３％であっ
た。Example 1 A commercially available spherical alumina (KHS-24; manufactured by Sumitomo Chemical Co., Ltd.) was calcined in air at 1300 ° C. for 3 hours to have a specific surface area of 5 m 2.
/ G of spherical alumina was obtained. Obtained spherical alumina 25
After filling ml into a quartz reaction tube having an inner diameter of 25 mm and a length of 350 mm, the reaction tube was fixed vertically, and the temperature of the catalyst layer was controlled at 350 ° C. by heating. Then, a methanol solution of dimethyl oxalate having a dimethyl oxalate concentration of 15% by weight was supplied at a rate of 12.1 g / hr from the upper part of the reaction tube. The reaction was carried out by supplying to the catalyst layer. At this time, the space velocity of the raw material gas containing dimethyl oxalate, methanol and nitrogen gas was 1022 hr -1 . After the reaction, the reaction solution obtained by collecting the solution in an ice-cooled trap was analyzed by gas chromatography, and the conversion of dimethyl oxalate was found to be 5%.
At 0.0%, the selectivity for dimethyl carbonate was 37.3%.
【００１８】実施例２ 市販の球状アルミナ（ＫＨＳ−２４；住友化学製）を空
気中、１１００℃で３時間焼成して、比表面積が２１ｍ
2 ／ｇの球状アルミナを得た。得られた球状アルミナ２
５ｍｌを用い、触媒層の温度を３００℃に変えたほか
は、実施例１と同様に反応と分析を行った。その結果、
シュウ酸ジメチルの転化率は８０．２％で、炭酸ジメチ
ルの選択率は２１．２％であった。Example 2 Commercially available spherical alumina (KHS-24; manufactured by Sumitomo Chemical Co., Ltd.) was calcined in air at 1100 ° C. for 3 hours to have a specific surface area of 21 m.
2 / g of spherical alumina was obtained. Obtained spherical alumina 2
The reaction and analysis were carried out in the same manner as in Example 1 except that 5 ml was used and the temperature of the catalyst layer was changed to 300 ° C. as a result,
The conversion of dimethyl oxalate was 80.2%, and the selectivity for dimethyl carbonate was 21.2%.
【００１９】実施例３ １〜２ｍｍφに破砕した水酸化マグネシウムを空気中、
８００℃で２時間焼成して、比表面積が２０ｍ2 ／ｇの
破砕状の酸化マグネシウム（マグネシア）を得た。得ら
れた破砕状マグネシア２５ｍｌを用い、触媒層の温度を
３００℃に変えたほかは、実施例１と同様に反応と分析
を行った。その結果、シュウ酸ジメチルの転化率は４
１．１％で、炭酸ジメチルの選択率は２７．４％であっ
た。Example 3 Magnesium hydroxide crushed to 1 to 2 mmφ was air-
By calcination at 800 ° C. for 2 hours, crushed magnesium oxide (magnesia) having a specific surface area of 20 m 2 / g was obtained. The reaction and analysis were carried out in the same manner as in Example 1, except that 25 ml of the obtained crushed magnesia was used and the temperature of the catalyst layer was changed to 300 ° C. As a result, the conversion of dimethyl oxalate was 4
At 1.1%, the selectivity for dimethyl carbonate was 27.4%.
【００２０】比較例１ 市販の球状アルミナ（ＫＨＳ−２４；住友化学製）を空
気中、１０００℃で３時間焼成して、比表面積が４０ｍ
2 ／ｇの球状アルミナを得た。得られた球状アルミナ２
５ｍｌを用い、触媒層の温度を２５０℃に変えたほか
は、実施例１と同様に反応と分析を行った。その結果、
シュウ酸ジメチルの転化率は７６．５％で、炭酸ジメチ
ルの選択率は１．３％であった。Comparative Example 1 A commercially available spherical alumina (KHS-24; manufactured by Sumitomo Chemical Co., Ltd.) was calcined in the air at 1000 ° C. for 3 hours to have a specific surface area of 40 m.
2 / g of spherical alumina was obtained. Obtained spherical alumina 2
The reaction and analysis were carried out in the same manner as in Example 1 except that the temperature of the catalyst layer was changed to 250 ° C. using 5 ml. as a result,
The conversion of dimethyl oxalate was 76.5%, and the selectivity for dimethyl carbonate was 1.3%.
【００２１】比較例２ 触媒層の温度を２３０℃に変えたほかは、比較例１と同
様に反応と分析を行った。その結果、シュウ酸ジメチル
の転化率は４５．０％で、炭酸ジメチルの選択率は０．
５％であった。Comparative Example 2 The reaction and analysis were carried out in the same manner as in Comparative Example 1 except that the temperature of the catalyst layer was changed to 230 ° C. As a result, the conversion of dimethyl oxalate was 45.0%, and the selectivity of dimethyl carbonate was 0.4%.
5%.
【００２２】比較例３ 市販の球状アルミナ（ＫＨＳ−２４；住友化学製）を空
気中、９００℃で３時間焼成して、比表面積が１０４ｍ
2 ／ｇの球状アルミナを得た。得られた球状アルミナ２
５ｍｌを用い、触媒層の温度を２００℃に変えたほか
は、実施例１と同様に反応と分析を行った。その結果、
シュウ酸ジメチルの転化率は９１．３％で、炭酸ジメチ
ルの選択率は０％であった。Comparative Example 3 A commercially available spherical alumina (KHS-24; manufactured by Sumitomo Chemical Co., Ltd.) was calcined in the air at 900 ° C. for 3 hours to have a specific surface area of 104 m.
2 / g of spherical alumina was obtained. Obtained spherical alumina 2
The reaction and analysis were carried out in the same manner as in Example 1 except that 5 ml was used and the temperature of the catalyst layer was changed to 200 ° C. as a result,
The conversion of dimethyl oxalate was 91.3%, and the selectivity of dimethyl carbonate was 0%.
【００２３】比較例４ 市販の球状アルミナ（ＫＨＳ−２４；住友化学製）を空
気中、１４５０℃で３時間焼成して、比表面積が３ｍ2
／ｇの球状アルミナを得た。得られた球状アルミナ２５
ｍｌを用い、触媒層の温度を３００℃に変えたほかは、
実施例１と同様に反応と分析を行った。その結果、シュ
ウ酸ジメチルの転化率は１５．４％で、炭酸ジメチルの
選択率は４．７％であった。実施例及び比較例の結果を
表１に示す。Comparative Example 4 A commercially available spherical alumina (KHS-24; manufactured by Sumitomo Chemical Co., Ltd.) was calcined in air at 1450 ° C. for 3 hours to have a specific surface area of 3 m 2.
/ G of spherical alumina was obtained. Obtained spherical alumina 25
ml, and the temperature of the catalyst layer was changed to 300 ° C.
The reaction and analysis were performed in the same manner as in Example 1. As a result, the conversion of dimethyl oxalate was 15.4%, and the selectivity of dimethyl carbonate was 4.7%. Table 1 shows the results of Examples and Comparative Examples.
【００２４】[0024]
【表１】 [Table 1]
【００２５】[0025]
【発明の効果】本発明により、シュウ酸ジアルキルを脱
カルボニル反応させて炭酸ジアルキルを製造する方法に
おいて、生成物及び触媒の分離・回収が容易な方法（即
ち、気相反応）によって、炭酸ジアルキルを容易に製造
することができる。また、本発明により、毒性の強い化
合物であるホスゲンを用いることなく、炭酸ジアルキル
を製造できる。According to the present invention, in a method for producing a dialkyl carbonate by subjecting a dialkyl oxalate to a decarbonylation reaction, the dialkyl carbonate can be easily separated and recovered by a method (that is, a gas phase reaction). It can be easily manufactured. Further, according to the present invention, dialkyl carbonate can be produced without using phosgene which is a highly toxic compound.
Claims (2)
３０ｍ2 ／ｇであるIIＡ族又はIII Ａ族金属の酸化物の
存在下、気相で脱カルボニル反応させることを特徴とす
る炭酸ジアルキルの製造方法。1. A dialkyl oxalate having a specific surface area of 5 to 5.
A process for producing a dialkyl carbonate, which comprises carrying out a decarbonylation reaction in the gas phase in the presence of an oxide of a Group IIA or Group IIIA metal at 30 m 2 / g.
であることを特徴とする請求項１記載の炭酸ジアルキル
の製造方法。2. The method for producing a dialkyl carbonate according to claim 1, wherein the metal oxide is alumina or magnesia.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8204681A JPH1045676A (en) | 1996-08-02 | 1996-08-02 | Production of dialkyl carbonate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8204681A JPH1045676A (en) | 1996-08-02 | 1996-08-02 | Production of dialkyl carbonate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1045676A true JPH1045676A (en) | 1998-02-17 |
Family
ID=16494550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8204681A Pending JPH1045676A (en) | 1996-08-02 | 1996-08-02 | Production of dialkyl carbonate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1045676A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115779883A (en) * | 2022-12-13 | 2023-03-14 | 新疆至臻化工工程研究中心有限公司 | Catalyst for directionally synthesizing alkyl carbonate from alkyl oxalate |
-
1996
- 1996-08-02 JP JP8204681A patent/JPH1045676A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115779883A (en) * | 2022-12-13 | 2023-03-14 | 新疆至臻化工工程研究中心有限公司 | Catalyst for directionally synthesizing alkyl carbonate from alkyl oxalate |
| CN115779883B (en) * | 2022-12-13 | 2024-07-02 | 新疆至臻化工工程研究中心有限公司 | Catalyst for directionally synthesizing alkyl carbonate from alkyl oxalate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS588073A (en) | Manufacture of 5-alkylbutyrolactone | |
| US5973184A (en) | Process for preparing a dialkyl carbonate by gas-phase decarbonylation of dialkyl oxalate | |
| Luithle et al. | Synthesis of enantiomerically pure cis‐cyclopropylboronic esters | |
| US7928251B2 (en) | Process for preparing tetramethyl glycolide | |
| US20140194648A1 (en) | Process for producing 2-ethylheptanoic acid | |
| JPH1045676A (en) | Production of dialkyl carbonate | |
| US3535371A (en) | Process for the preparation of acrylic esters | |
| Hao et al. | Gas phase decarbonylation of diethyl oxalate to diethyl carbonate over alkali-containing catalyst | |
| JP2004131411A (en) | Method for purifying glycolic acid ester and method for producing glycolic acid ester | |
| CN116143695B (en) | Synthesis method of 1, 1-difluoro-5-azaspiro [2.5] octane hydrochloride | |
| JP3489324B2 (en) | Method for producing diaryl carbonate | |
| JP2971428B2 (en) | Recovery method of alkyl vinyl ether | |
| JPH0834762A (en) | Production of alpha-ketonic acid ester | |
| JPH09286603A (en) | Production of gaseous mixture of carbon monoxide and hydrogen | |
| WO2001010811A1 (en) | Process for the preparation of methyl methacrylate | |
| JPS6210982B2 (en) | ||
| JPH08325206A (en) | Production of diaryl carbonate | |
| JPS58159433A (en) | Preparation of ethylene glycol | |
| JP2757403B2 (en) | Process for producing 2,3-dimethylbutenes | |
| JPS6025955A (en) | Production of gamma-chloroacetoacetic acid ester | |
| JP5626871B2 (en) | Method for producing hydropyrans | |
| JPS62277338A (en) | Method for purifying o-methylacetophenone | |
| JPH07258164A (en) | Production of alpha-ketonic acid ester | |
| SU425899A1 (en) | A METHOD FOR OBTAINING CYCLOPROPANKARCARBONIC ACID ESTERS ... - - ^ .-. > & f \ n '; ^ '^ v' '• -:; , i ^ H I 4 '“VUj: 4' ^ ''" '' '' 'iJJ'l ^ | |
| EP0043631B1 (en) | Process for the preparation of a 6-alkyl-valerolactone |