Asinger reaction
{{Reactionbox
|Name = Asinger reaction
|Type = Ring forming reaction
|NamedAfter = Friedrich Asinger
|Section3 = {{Reactionbox Identifiers
|RSC_ontology_id = 0000688
}}
}}
The Asinger-reaction (sometimes referred to as the Asinger-4 component reaction or A-4CR for short) is a multicomponent reaction for the synthesis of 3-thiazolines and other related heterocycles.{{cite journal |last1=Asinger |first1=F. |last2=Offermanns |first2=H. |title=Syntheses with ketones, sulfur, and ammonia or amines at room temperature |journal=Angewandte Chemie International Edition in English |date=November 1967 |volume=6 |issue=11 |pages=907–919 |doi=10.1002/anie.196709071}} It is named after Friedrich Asinger who first reported it in 1956.{{cite journal |last1=Asinger |first1=F. |title=Über die gemeinsame Einwirkung von Schwefel und Ammoniak auf Ketone |journal=Angewandte Chemie |date=21 June 1956 |volume=68 |issue=12 |pages=413 |doi=10.1002/ange.19560681209|bibcode=1956AngCh..68..413A}}
Process
An α-halogenated carbonyl-component reacts with sodium hydrosulfide (NaSH) and forms a Thiol in situ. The thiol reacts directly with another carbonyl component and ammonia to form a thiazoline. The reaction works also by using elemental sulphur, an α–substituted ketone, another carbonyl component and ammonia; in this case, a mixture of products is formed.
The formation of 3-thiazolines also occurs by using α-thioaldehyde or α-thioketone and ammonia.{{cite journal |last1=Asinger |first1=F. |last2=Thiel |first2=M. |title=Einfache Synthesen und chemisches Verhalten neuer heterocyclischer Ringsysteme |journal=Angewandte Chemie |date=26 November 1958 |volume=70 |issue=22–23 |pages=667–683 |doi=10.1002/ange.19580702202|bibcode=1958AngCh..70..667A}}
A simplified route of the Asinger-reaction was developed at Degussa. An α-halogenated carbonyl compound reacts with sodium hydrosulfide (NaSH) and forms a thiol in situ which reacts directly with aldehydes or ketones and ammonia to 3-thiazolines.{{cite journal |last1=Drauz |first1=Karlheinz |last2=Koban |first2=Hans Günter |last3=Martens |first3=Jürgen |last4=Schwarze |first4=Wolfgang |title=Phosphonic and Phosphinic Acid Analogs of Penicillamine |journal=Liebigs Annalen der Chemie |date=12 March 1985 |volume=1985 |issue=3 |pages=448–452 |doi=10.1002/jlac.198519850303}} The chemical industry developed based on the Asinger-reaction multi stage processes for the production of pharmaceuticals like D-penicillamine{{cite journal |last1=Weigert |first1=Wolfgang M. |last2=Offermanns |first2=Heribert |last3=Scherberich |first3=Paul |title=D-Penicillamin - Herstellung und Eigenschaften |journal=Angewandte Chemie |date=May 1975 |volume=87 |issue=10 |pages=372–378 |doi=10.1002/ange.19750871003|bibcode=1975AngCh..87..372W}} and the aminoacid DL-cysteine.{{cite journal |last1=Martens |first1=Jürgen |last2=Offermanns |first2=Heribert |last3=Scherberich |first3=Paul |title=Einfache Synthese von racemischem Cystein |journal=Angewandte Chemie |date=August 1981 |volume=93 |issue=8 |pages=680–683 |doi=10.1002/ange.19810930808|bibcode=1981AngCh..93..680M}}
File:Asinger Reaction Penicilliamin.svg by the Asinger reaction]]
References
{{Reflist}}
Literature
- {{cite journal | journal = Angewandte Chemie | volume = 68 | issue = 11 | year = 1956| pages = 377| doi = 10.1002/ange.19560681109| title = Chemiker-Treffen Salzburg: Über die einfache und ergiebige Synthese von Thiazolonen | author = Friedrich Asinger}}
- {{cite journal | journal = Angewandte Chemie | volume = 68 | issue = 12 | year = 1956 | pages = 413 | doi = 10.1002/ange.19560681209 | title = Über die gemeinsame Einwirkung von Schwefel und Ammoniak auf Ketone | author = Friedrich Asinger| bibcode = 1956AngCh..68..413A}}
- {{cite journal | journal = Tetrahedron Letters | volume = 41 | issue = 38 | year = 2000 | pages = 7289–7292 | doi = 10.1016/S0040-4039(00)01266-1 | title = Synthesis of the first enantiomerically pure 3-thiazolines via Asinger reaction |author1=Imre Schlemminger |author2=Hans-Hermann Janknecht |author3=Wolfgang Maison |author4=Wolfgang Saak |author5=Jürgen Martens}}
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Category:Multiple component reactions