DE421021C - Process for the preparation of acetylsalicylic acid - Google Patents
Process for the preparation of acetylsalicylic acidInfo
- Publication number
- DE421021C DE421021C DEG51291D DEG0051291D DE421021C DE 421021 C DE421021 C DE 421021C DE G51291 D DEG51291 D DE G51291D DE G0051291 D DEG0051291 D DE G0051291D DE 421021 C DE421021 C DE 421021C
- Authority
- DE
- Germany
- Prior art keywords
- preparation
- acetylsalicylic acid
- ethylidene diacetate
- acid
- acetic acid
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
- C07C69/76—Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring
- C07C69/84—Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring of monocyclic hydroxy carboxylic acids, the hydroxy groups and the carboxyl groups of which are bound to carbon atoms of a six-membered aromatic ring
- C07C69/86—Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring of monocyclic hydroxy carboxylic acids, the hydroxy groups and the carboxyl groups of which are bound to carbon atoms of a six-membered aromatic ring with esterified hydroxyl groups
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
Verfahren zur Darstellung von Acetylsalicylsäure. Es ist bekannt, daß -Äthylidendiacetat unter bestimmten Bedingungen, z. B. durch Erhitzen der Dämpfe auf 25o bis 300°, in Acetaldehyd und Essigsäureanhydrid zerfällt. Um diesen Zerfall bei wesentlich niedrigeren Temperaturen herbeizuführen, setzt man Katalysatoren zu. Bei den bisher in der Literatur erwähnten Fällen der Acetylierung von organischen Verbindungen mittels Äthylidendiacetat handelt es sich nur um leicht, schon durch Erwärmen mit Eisessig acetylierbare Produkte, wie Alkohole oder Phenylhydrazin (vgl. hierzu Monatshefte f. Chem. 30, S. 84.5, Abs. 2). .Process for the preparation of acetylsalicylic acid. It is known, that ethylidene diacetate under certain conditions, e.g. B. by heating the vapors to 25o to 300 °, decomposes into acetaldehyde and acetic anhydride. About this decay To bring about at much lower temperatures, one uses catalysts to. In the cases of acetylation of organic compounds mentioned so far in the literature Compounds by means of ethylidene diacetate are only easy, already through Warm up with glacial acetic acid products that can be acetylated, such as alcohols or phenylhydrazine (cf. on this, monthly bulletins f. Chem. 30, p. 84.5, paragraph 2). .
Es hat sich nun überraschenderweise gezeigt, daß die Einführung der Acetylgruppe in die im Verhältnis zu Alkoholen und Acvlhydrazinen schwieriger acetylierbare Salicylsäure mühelos und glatt gelingt, wenn man diese Verbindung mit Äthylidendiacetat ohne jede---i weiteren Zusatz -zum Sieden erhitzt. Neben Acetylsalicylsäure entstehen dabei Essigsäure und Acetaldehyd.It has now been shown, surprisingly, that the introduction of the Acetyl group in the more difficult to acetylate in relation to alcohols and acylhydrazines Salicylic acid succeeds effortlessly and smoothly when you combine this with ethylidene diacetate heated to boiling without any --- i further addition. In addition to acetylsalicylic acid arise acetic acid and acetaldehyde.
Der technische Wert des neuen Verfahrens liegt darin, daß der als Nebenprodukt entstehende Acetaldehy d nach bekannten Methoden sich glatt in Essigsäure überführen läßt, die wiederum, wie bekannt, durch Einleiten von Acetylen in Äthvlidendiacetat zurückverwandelt werden kann. Das Verfahren läuft also darauf hinaus, daß man als Ausgangsstoff für die Einführung der Acetylgruppe in der Hauptsache nur das billige Acetylen benötigt.The technical value of the new process lies in the fact that the as Acetaldehydes formed by the by-product are converted smoothly into acetic acid by known methods can be transferred, which in turn, as is known, by introducing acetylene into Äthvlidendiacetat can be converted back. So the process boils down to being The starting material for the introduction of the acetyl group is mainly cheap Acetylene needed.
Beispiel: Die Lösung von 6 kg Salicylsäure in ro kg Äthylidendiacetat wird 5 Stunden unter Rückfluß gekocht, wobei man die sich kondensierenden Dämpfe nur so weit kühlt, daß das Äthylidendiacetat und die sich bildende Essigsäure, nicht aber der Acetaldehyd, in das Kochgefäß zurückfließen. Der Acetaldehyd wird in einer Vorlage gesammelt. Aus dem Reaktionsprodukt werden die Essigsäure und ein Teil des überschüssig vorhandenen Äthylidendiacetats abdestilliert. Der Rückstand erstarrt zu einem Kristallbrei von Acetylsalicylsäure, die nach dem Absaugen und Umkristallisieren aus passenden Lösungsmitteln rein erhalten wird. Die Ausbeute beträgt ungefähr 70 Prozent der Theorie. Der Rest kann aus der Mutterlauge durch Eindampfen zur Trockne in unreinerer Form gewonnen und entweder durch Umkristallisieren gereinigt oder durch Kochen mit Natronlauge in Salicylsäure zurückverwandelt werden.Example: The solution of 6 kg of salicylic acid in ro kg of ethylidene diacetate is refluxed for 5 hours, whereby the condensing vapors are only cooled to such an extent that the ethylidene diacetate and the acetic acid formed, but not the acetaldehyde, flow back into the cooking vessel. The acetaldehyde is collected in a receiver. The acetic acid and part of the excess ethylidene diacetate present are distilled off from the reaction product. The residue solidifies to form a crystal slurry of acetylsalicylic acid, which is obtained in pure form after suction and recrystallization from suitable solvents. The yield is about 70 percent of theory. The remainder can be obtained in impure form from the mother liquor by evaporation to dryness and either purified by recrystallization or converted back into salicylic acid by boiling with sodium hydroxide solution.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEG51291D DE421021C (en) | 1920-06-23 | 1920-06-23 | Process for the preparation of acetylsalicylic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEG51291D DE421021C (en) | 1920-06-23 | 1920-06-23 | Process for the preparation of acetylsalicylic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE421021C true DE421021C (en) | 1925-11-04 |
Family
ID=7129711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DEG51291D Expired DE421021C (en) | 1920-06-23 | 1920-06-23 | Process for the preparation of acetylsalicylic acid |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE421021C (en) |
-
1920
- 1920-06-23 DE DEG51291D patent/DE421021C/en not_active Expired
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