JPS644512B2 - - Google Patents

Info

Publication number
JPS644512B2
JPS644512B2 JP56112632A JP11263281A JPS644512B2 JP S644512 B2 JPS644512 B2 JP S644512B2 JP 56112632 A JP56112632 A JP 56112632A JP 11263281 A JP11263281 A JP 11263281A JP S644512 B2 JPS644512 B2 JP S644512B2
Authority
JP
Japan
Prior art keywords
reaction
dihydropyran
alkoxytetrahydropyran
ethoxytetrahydropyran
potassium
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.)
Expired
Application number
JP56112632A
Other languages
Japanese (ja)
Other versions
JPS5813581A (en
Inventor
Kazuyuki Matsuoka
Kyoshi Yasuda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daicel Corp
Original Assignee
Daicel Chemical Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Daicel Chemical Industries Ltd filed Critical Daicel Chemical Industries Ltd
Priority to JP56112632A priority Critical patent/JPS5813581A/en
Publication of JPS5813581A publication Critical patent/JPS5813581A/en
Publication of JPS644512B2 publication Critical patent/JPS644512B2/ja
Granted legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/50Improvements relating to the production of bulk chemicals
    • Y02P20/52Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Landscapes

  • Pyrane Compounds (AREA)
  • Catalysts (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

本発明は2−アルコキシテトラヒドロピランを
カリウムでイオン交換したA型の合成ゼオライト
上で気相で熱分解することによつてジヒドロピラ
ンを製造する方法に関するものである。 目的生成物であるジヒドロピランは例えば、油
化学第29巻第11号第832頁(1980)等に記載があ
る如く、広い範囲の有機合成反応の原料として応
用され興味深い化合物である。従来、3.4−ジヒ
ドロ−2H−ピラン(ジヒドロピラン)の製造は
触媒として酸化アルミニウムを用いて、テトラヒ
ドロフルフリルアルコールを気相反応(脱水−環
拡大)させる方法等が知られている(Organic
Syntheses Coll.vol 第276頁(1955))。しか
しながら、これ等の方法では収率が66〜70%と低
く、必らずしも工業的に満足できる成積ではな
い。 本発明者らはジヒドロピランの新規な合成法に
ついて鋭意検討した結果、2−アルコキシテトラ
ヒドロピランをカリウムでイオン交換したA型の
合成ゼオライト上で熱分解することにより高収率
で、且つ経済的に有利なジヒドロピランが製造出
来ることを見い出した。 本発明に用いる触媒はA型の合成ゼオライトを
カリウムでイオン交換したものであり、具体的に
は次の商品名で市販されている。 モレキユラーシーブ3A(UCC社)、ゼオラムA
−3(東洋ソーダ社)バイリツトS(バイエル社)
等が好適に使用でき、また、モレキユラーシーブ
4A、ゼオラムA−4、バイリツトTをカリウム
イオンにより交換吸着して使用することも出来
る。該合成ゼオライトは市販の成型品(ペレツ
ト)、粉末品をそのまま使用することができる。 この場合、カリウムでイオン交換されたA型の
ゼオライトは細孔径4Å以下を有しており、この
4Å以下であることが本反応に対して重要な意味
をもち、これ以上の細光径では副反応が起き、好
ましくない。 本発明における反応の一般式は次の通りであ
り、 (但し、Rは炭素数1〜6を有する低級アルキル
基を表わす。) 原料として使用される2−アルコキシテトラヒ
ドロピランは具体的には2−メトキシテトラヒド
ロピラン、2−エトキシテトラヒドロピラン、2
−プロポキシテトラヒドロピラン、2−ブトキシ
テトラヒドロピラン等が挙げられる。 本発明を実施する場合、反応温度は接触時間及
び使用する原料により異なるが、250〜400℃の範
囲が適当であり、接触時間は10〜60秒の範囲が適
当である。 反応方法は固定床、流動床等のいずれでも、又
常圧、減圧、加圧下のいずれの方法で行なつても
よいが、通常は操作の容易な固定床/常圧下で実
施すれば満足すべき成績が得られる。熱分解から
得られた反応生成物は冷却、凝縮された後、これ
を蒸溜分離することによつて、容易に目的生成物
を得ることができる。 次に、実施例により本発明を更に具体的に説明
する。 なお、各原料、生成物はガスクロマトグラフイ
で分析し、反応生績は次式で計算した。 変化率(%)=反応2−アルコキシテトラヒドロ
ピラン(モル)/仕込2−アルコキシテトラヒドロピラ
ン(モル)×100 選択率(%)=生成ジヒドロピラン(モル)/反
応2−アルコキシテトラヒドロピラン(モル)×100 収率(%)=生成ジヒドロピラン(モル)/仕込
2−アルコキシテトラヒドロピラン(モル)×100 実施例 1 市販の粒径3.2mmφのモレキユラーシーブ3A60
mlを内径28mmφのステンレス製U字型反応管に充
填し、285℃(反応温度)に加熱した触媒上に2
−エトキシテトラヒドロピランを接触時間38秒に
なるように供給したところ、2−エトキシテトラ
ヒドロピランの変化率98.1%でジヒドロピランの
選択率97.9%であり、ジヒドロピランの収率96.0
%を得た。 実施例 2 実施例1の反応温度を295℃及び接触時間を30
秒に変更した以外は同一の方法で反応した。結果
は2−エトキシテトラヒドロピランの変化率98.5
%でジヒドロピランの選択率99.1%でジヒドロピ
ランの収率97.6%を得た。 実施例 3 実施例1と同一の触媒を用い、原料2−アルコ
キシテトラヒドロピランをヒドロピラン及び2−
ブトキシテトラヒドロピランに変更した以外は実
施例1と同一の方法で反応した。結果は次の通
り。
The present invention relates to a process for producing dihydropyrans by pyrolysis of 2-alkoxytetrahydropyrans in the gas phase on synthetic zeolites of type A ion-exchanged with potassium. The desired product, dihydropyran, is an interesting compound that can be used as a raw material for a wide range of organic synthesis reactions, as described, for example, in Yukagaku Vol. 29, No. 11, p. 832 (1980). Conventionally, 3,4-dihydro-2H-pyran (dihydropyran) has been produced by a method in which tetrahydrofurfuryl alcohol is subjected to a gas phase reaction (dehydration-ring expansion) using aluminum oxide as a catalyst.
Syntheses Coll. vol. 276 (1955)). However, these methods have low yields of 66 to 70%, and are not necessarily industrially satisfactory. As a result of intensive studies on a new method for synthesizing dihydropyran, the present inventors found that 2-alkoxytetrahydropyran can be thermally decomposed on A-type synthetic zeolite ion-exchanged with potassium in a high yield and economically. It has been found that advantageous dihydropyrans can be prepared. The catalyst used in the present invention is a type A synthetic zeolite ion-exchanged with potassium, and specifically, it is commercially available under the following trade name. Molecular sieve 3A (UCC), Zeorum A
-3 (Toyo Soda Co., Ltd.) Bayritt S (Bayer Co., Ltd.)
etc. can be used suitably, and molecular sieves can also be used.
4A, Zeolum A-4, and Bayritt T can also be used after being exchange-adsorbed with potassium ions. As the synthetic zeolite, commercially available molded products (pellets) or powder products can be used as they are. In this case, the A-type zeolite ion-exchanged with potassium has a pore diameter of 4 Å or less, and this 4 Å or less has an important meaning for this reaction; A reaction occurs and is not desirable. The general formula of the reaction in the present invention is as follows, (However, R represents a lower alkyl group having 1 to 6 carbon atoms.) Specifically, the 2-alkoxytetrahydropyran used as a raw material includes 2-methoxytetrahydropyran, 2-ethoxytetrahydropyran, 2-ethoxytetrahydropyran, and 2-alkoxytetrahydropyran.
-propoxytetrahydropyran, 2-butoxytetrahydropyran and the like. When carrying out the present invention, the reaction temperature varies depending on the contact time and the raw materials used, but is suitably in the range of 250 to 400°C, and the contact time is suitably in the range of 10 to 60 seconds. The reaction may be carried out in either a fixed bed or a fluidized bed, or under normal pressure, reduced pressure, or increased pressure, but it is usually satisfactory if the reaction is carried out in a fixed bed or under normal pressure, which is easy to operate. You can get the desired results. The reaction product obtained from the thermal decomposition is cooled and condensed, and then separated by distillation to easily obtain the desired product. Next, the present invention will be explained in more detail with reference to Examples. In addition, each raw material and product were analyzed by gas chromatography, and the reaction performance was calculated using the following formula. Change rate (%) = Reaction 2-alkoxytetrahydropyran (mol) / Charged 2-alkoxytetrahydropyran (mol) x 100 Selectivity (%) = Produced dihydropyran (mol) / Reaction 2-alkoxytetrahydropyran (mol) x 100 Yield (%) = Produced dihydropyran (mol) / Charged 2-alkoxytetrahydropyran (mol) x 100 Example 1 Commercially available molecular sieve 3A60 with a particle size of 3.2 mmφ
ml was filled into a stainless steel U-shaped reaction tube with an inner diameter of 28 mmφ, and placed on a catalyst heated to 285°C (reaction temperature).
- When ethoxytetrahydropyran was fed for a contact time of 38 seconds, the conversion rate of 2-ethoxytetrahydropyran was 98.1%, the selectivity of dihydropyran was 97.9%, and the yield of dihydropyran was 96.0%.
I got %. Example 2 The reaction temperature of Example 1 was changed to 295°C and the contact time was changed to 30°C.
I reacted in the same way except that I changed it to seconds. The result is a conversion rate of 2-ethoxytetrahydropyran of 98.5.
%, a selectivity of dihydropyran of 99.1% and a yield of dihydropyran of 97.6% were obtained. Example 3 Using the same catalyst as in Example 1, raw material 2-alkoxytetrahydropyran was converted into hydropyran and 2-
The reaction was carried out in the same manner as in Example 1 except that butoxytetrahydropyran was used. The results are as follows.

【表】 なお、シリカ−アルミナ触媒を用いて実施例1
に従つて2−エトキシテトラヒドロピランの熱分
解を行つたが、副反応が助長され、芳しい成績は
得られなかつた。
[Table] In addition, Example 1 using a silica-alumina catalyst
Although 2-ethoxytetrahydropyran was thermally decomposed according to the method described above, side reactions were promoted and good results were not obtained.

Claims (1)

【特許請求の範囲】[Claims] 1 カリウムでイオン交換したA型の合成ゼオラ
イトの存在下に、2−アルコキシテトラヒドロピ
ランを気相で熱分解することを特徴とするジヒド
ロピランの製造法。
1. A method for producing dihydropyran, which comprises thermally decomposing 2-alkoxytetrahydropyran in the gas phase in the presence of synthetic A-type zeolite ion-exchanged with potassium.
JP56112632A 1981-07-17 1981-07-17 Production of dihydropyran Granted JPS5813581A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56112632A JPS5813581A (en) 1981-07-17 1981-07-17 Production of dihydropyran

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56112632A JPS5813581A (en) 1981-07-17 1981-07-17 Production of dihydropyran

Publications (2)

Publication Number Publication Date
JPS5813581A JPS5813581A (en) 1983-01-26
JPS644512B2 true JPS644512B2 (en) 1989-01-25

Family

ID=14591582

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56112632A Granted JPS5813581A (en) 1981-07-17 1981-07-17 Production of dihydropyran

Country Status (1)

Country Link
JP (1) JPS5813581A (en)

Also Published As

Publication number Publication date
JPS5813581A (en) 1983-01-26

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