CH309175A - Process for the preparation of pyridine-4-aldehyde. - Google Patents
Process for the preparation of pyridine-4-aldehyde.Info
- Publication number
- CH309175A CH309175A CH309175DA CH309175A CH 309175 A CH309175 A CH 309175A CH 309175D A CH309175D A CH 309175DA CH 309175 A CH309175 A CH 309175A
- Authority
- CH
- Switzerland
- Prior art keywords
- pyridyl
- carbinol
- pyridine
- aldehyde
- brought
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/24—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with substituted hydrocarbon radicals attached to ring carbon atoms
- C07D213/44—Radicals substituted by doubly-bound oxygen, sulfur, or nitrogen atoms, or by two such atoms singly-bound to the same carbon atom
- C07D213/46—Oxygen atoms
- C07D213/48—Aldehydo radicals
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
Description
Verfahren zur Herstellung von Pyridin-4-aldehyd. Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Pyridin-4- aldeliyd, welches dadurch gekennzeichnet ist, dass man Pyridyl-4-earbinol zusammen mit einem 'Sauerstoff enthaltenden Gasgemisch, vorzugsweise Luft, bei einer Temperatur von 200 bis 400 C mit einem Oxydationskatalysa tor in Kontakt bringt.
Die Reaktion wird zweckmässig wie folgt durchgeführt : Pyridyl-4-carbinol wird ver dampft und in einem mit Silber oder Kupfer besehiekten Rohr, das auf etwa 250 bis 3'50 C erhitzt ist, mit einem Luftstrom in Berüh rung gebracht. Durch Kondensation der Re aktionsgase und anschliessende Rektifikation erhält man den Aldehyd in guter Ausbeute und reiner Form. Am besten wird ein senk reeht stehendes Aluminiumrohr, das auf einem wesentlichen 'Teil seiner Länge von einem elek trischen Ofen aufgeheizt werden kann, ver wendet. Als Katalysator wirkt eine Füllung von fein verteiltem Kupfer oder Silber, wie Kupferdrahtnetz, Silberdrahtnetz, :Silberspäne oder Silberwolle.
Die mit konzentrierter Schwefelsäure getrocknete und durch Watte filtrierte Luft kann durch das Rohr entweder durchgeblasen oder durchgesogen werden, wo bei die Strömungsgeschwindigkeit mit einem Rotameter gemessen wird. Das Pyridyl - 4 earbinol wird auf eine Temperatur oberhalb seines Schmelzpunktes vorgewärmt und mit tels eines beheizten Tropftrichters vom obern Ende des Reaktionsrohres her in die beheizte Zone des Rohres gebracht. Die Luft strömt im Rohr von unten nach oben und begegnet dem Pyridin-4-carbinol in unmittelbarer Ge genwart des erhitzten Katalysators.
Nach dein Verlassen des Rohres werden die Reaktions dämpfe durch einen am obern Rohrende be festigten Destillierbogen abgeleitet und in einer weitlumigen, auf etwa -10" C gekühl ten Kühlschlange kondensiert. Das Kondensat, das zur Hauptsache aus Pyridin=4-aldehyd, Pyridyl-4-carbinol und Wasser besteht, wird in einem tiefgekühlten Auffanggefäss gesam melt. Der Pyridin-4-aldehyd soll als zwischen- produkt verwendet werden.
<I>Beispiel:</I> 22 g Pyridyl-4-carbinol lässt man mit einer Geschwindigkeit von 7 bis 9 Tropfen pro Mi nute in ein auf 280 C geheiztes und mit Sil- berdrehspänen als Katalysator beschicktes Re aktionsrohr eintropfen. Von unten her leitet man getrocknete und filtrierte Luft mit einer Geschwindigkeit von 3 Litern/Minute durch das Rohr. Nachdem nach etwa 1 bis 11/4 Stun den alles Pyridyl-4-carbinol zugetropft ist, lässt man die Luft noch eine weitere Stunde durch das beheizte Rohr strömen. Im Auf fanggefäss sammeln sich 22. bis 23g Konden sat an.
Aus dem Kondensat erhält man durch einmaliges Fraktionieren einen geringen, aus Wasser und Pyridin-4-aldehyd bestehenden Vorlauf, 11 g Pyridin-4-aldehyd (Kp.2o "", 90 bis 91 C) und 7 g unverändertes Pyridyl- 4-carbinol. Unter Berücksichtigung der Wie- dergewinnLing von etwa 3,011/o Pyridyl-4- carbinol beträgt die Ausbeute an Aldehyd 71%.
Process for the preparation of pyridine-4-aldehyde. The present invention relates to a process for the preparation of pyridine-4-aldeliyd, which is characterized in that pyridyl-4-earbinol together with an 'oxygen-containing gas mixture, preferably air, at a temperature of 200 to 400 C with an oxidation catalyst brings in contact.
The reaction is conveniently carried out as follows: Pyridyl-4-carbinol is evaporated and brought into contact with a stream of air in a tube covered with silver or copper, which is heated to about 250 to 3'50 C. By condensation of the reaction gases and subsequent rectification, the aldehyde is obtained in good yield and in pure form. It is best to use a vertical aluminum tube that can be heated by an electric furnace over a substantial part of its length. A filling of finely divided copper or silver, such as copper wire mesh, silver wire mesh: silver shavings or silver wool, acts as a catalyst.
The air, dried with concentrated sulfuric acid and filtered through cotton wool, can either be blown or sucked through the tube, where the flow rate is measured with a rotameter. The pyridyl-4-earbinol is preheated to a temperature above its melting point and brought into the heated zone of the tube from the upper end of the reaction tube using a heated dropping funnel. The air flows in the tube from bottom to top and meets the pyridine-4-carbinol in the immediate presence of the heated catalyst.
After leaving the tube, the reaction vapors are diverted through a distillation elbow attached to the upper end of the tube and condensed in a large cooling coil, cooled to about -10 "C. The condensate, which mainly consists of pyridine = 4-aldehyde, pyridyl-4 -carbinol and water, is collected in a frozen collecting vessel. The pyridine-4-aldehyde should be used as an intermediate product.
<I> Example: </I> 22 g of pyridyl-4-carbinol are allowed to drop at a rate of 7 to 9 drops per minute into a reaction tube heated to 280 C and charged with silver turnings as a catalyst. Dried and filtered air is passed through the tube from below at a rate of 3 liters / minute. After all the pyridyl-4-carbinol has been added dropwise after about 1 to 11/4 hours, the air is allowed to flow through the heated tube for a further hour. 22 to 23 g of condensate collect in the collecting vessel.
A small first run consisting of water and pyridine-4-aldehyde, 11 g of pyridine-4-aldehyde (boiling point 20 "", 90 to 91 ° C.) and 7 g of unchanged pyridyl-4-carbinol are obtained from the condensate by fractionating once . Taking into account the recovery of about 3.011 / o pyridyl-4-carbinol, the aldehyde yield is 71%.
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH309175T | 1952-11-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CH309175A true CH309175A (en) | 1955-08-31 |
Family
ID=4493744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CH309175D CH309175A (en) | 1952-11-27 | 1952-11-27 | Process for the preparation of pyridine-4-aldehyde. |
Country Status (1)
| Country | Link |
|---|---|
| CH (1) | CH309175A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0356843A2 (en) * | 1988-08-27 | 1990-03-07 | BASF Aktiengesellschaft | Process for the preparation of heteroaromatic aldehydes and ketones |
-
1952
- 1952-11-27 CH CH309175D patent/CH309175A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0356843A2 (en) * | 1988-08-27 | 1990-03-07 | BASF Aktiengesellschaft | Process for the preparation of heteroaromatic aldehydes and ketones |
| EP0356843A3 (en) * | 1988-08-27 | 1991-04-03 | BASF Aktiengesellschaft | Process for the preparation of heteroaromatic aldehydes and ketones |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bauer | The preparation of fatty acid chlorides | |
| CH309175A (en) | Process for the preparation of pyridine-4-aldehyde. | |
| US2533086A (en) | Hydroxymethylthianaphthene | |
| CH286108A (en) | Process for the preparation of pyridine-3-aldehyde. | |
| DE826294C (en) | Process for the production of cyclohexene | |
| DE923185C (en) | Process for the production of epoxycyclooctane by oxidation of cyclooctene | |
| DE1204230B (en) | Process for the preparation of 3, 4-lutidine | |
| DE704663C (en) | Process for the preparation of saturated aliphatic aldehydes | |
| DE1055522B (en) | Process for the purification of terephthalic acid diesters of lower aliphatic alcohols | |
| DE858698C (en) | Process for the preparation of pyridine and quinoline derivatives | |
| AT222103B (en) | Process for the preparation of 2-trans-β-ionylideneacetic acid | |
| US2021872A (en) | Divintrl ether and processes for its | |
| DE2056132C3 (en) | Process for the production of glycerol acetates | |
| DE873688C (en) | Process for the production of chlorine by reacting hydrogen chloride with oxygen | |
| DE545161C (en) | Process for temperature control in catalytic reactions | |
| GB744074A (en) | Improvements in or relating to the purification of titanium tetrachloride | |
| DE899197C (en) | Process for the production of thymol | |
| AT238165B (en) | Process for the production of 2,6-dichlorobenzaldehyde | |
| DE952092C (en) | Process for the preparation of dihydrodifuran | |
| CH137389A (en) | Process for the preparation of 1-methylbutadiene-1.3. | |
| AT235274B (en) | Process for the production of 3,4-dichloromandelic acid and its methyl ether | |
| DE845506C (en) | Process for the production of acetaldehyde | |
| Crossley et al. | SYNTHESES OF A SERIES OF 15-KETOGLYCOLS AND 15-KETO FATTY ACIDS FROM USTILIC ACID | |
| DE1618312A1 (en) | Process for the production of unsaturated organic compounds | |
| DE887815C (en) | Process for the preparation of disubstituted carboxylic acid diamides |