Thiazoline
Thiazolines (or dihydrothiazoles) are a group of isomeric 5-membered heterocyclic compounds containing both sulfur and nitrogen in the ring. Although unsubstituted thiazolines are rarely encountered themselves, their derivatives are more common and some are bioactive. For example, in a common post-translational modification, cysteine residues are converted into thiazolines.[1]
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Names | |
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IUPAC names
2,3-Dihydrothiazole 2,5-Dihydrothiazole 4,5-Dihydrothiazole | |
Other names
2,3-Dihydro-1,3-thiazole or 4-thiazoline 2,5-Dihydro-1,3-thiazole or 3-thiazoline 4,5-Dihydro-1,3-thiazole or 2-thiazoline | |
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Properties | |
C3H5NS | |
Molar mass | 87.14 g·mol−1 |
Appearance | Colorless liquids |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
The name thiazoline originates from the Hantzsch–Widman nomenclature.
Isomers
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Three structural isomers of thiazoline exist depending on the position of the double bond. These forms do not readily interconvert and hence are not tautomers. Of these 2-thiazoline is the most common.
A fourth structure exists in which the N and S atoms are adjacent; this known as isothiazoline.
Synthesis
Thiazolines were first prepared by dialkylation of thioamides by Richard Willstatter in 1909.[2] 2-Thiazolines are commonly prepared from 2-aminoethanethiols (e.g. cysteamine).[3] They may also be synthesized via the Asinger reaction.
Applications
Many molecules contain thiazoline rings, one example being Firefly luciferin, the light-emitting molecule in fireflies. The amino acid cysteine is produced industrially from substituted thiazole.[3] 2-Aminothiazoline-4-carboxylic acid is an intermediate in the industrial synthesis of L-cysteine.[4]
See also
- Thiazole - an analogue with 2 double bonds
- Thiazolidine - an analogue with no double bonds
- Oxazoline - an analogue with O in place of S
References
- Walsh, Christopher T.; Nolan, Elizabeth M. (2008). "Morphing peptide backbones into heterocycles". Proceedings of the National Academy of Sciences USA. 105 (15): 5655–5656. Bibcode:2008PNAS..105.5655W. doi:10.1073/pnas.0802300105. PMC 2311349. PMID 18398003.
- Willstätter, Richard; Wirth, Theodor (1909). "Über Thioformamid". Chem. Ber. 42 (2): 1908–1922. doi:10.1002/cber.19090420267.
- Gaumont, Annie-Claude; Gulea, Mihaela; Levillain, Jocelyne (11 March 2009). "Overview of the Chemistry of 2-Thiazolines". Chemical Reviews. 109 (3): 1371–1401. doi:10.1021/cr800189z. PMID 19154153.
- Karlheinz Drauz, Ian Grayson, Axel Kleemann, Hans-Peter Krimmer, Wolfgang Leuchtenberger, Christoph Weckbecker (2006). Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_057.pub2.
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