Thiazoline

Thiazoline

Names
IUPAC name 4,5-dihydro-1,3-thiazole
Other names 4,5-Dihydrothiazole
Identifiers
CAS Number	504-79-0
Jmol interactive 3D	Image
PubChem	120269
SMILES C1CSC=N1
Properties
Chemical formula	C3H5NS
Appearance	colourless liquid
Boiling point	135 to 138 °C (275 to 280 °F; 408 to 411 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Thiazoline is a heterocyclic compound containing both sulfur and nitrogen in the ring. Although thiazoline itself is rarely encountered, its derivatives are often bioactive. For example, in a common post-translational modification, cysteine residues are converted into thiazolines.^[1]

Synthesis

Thiazolines were first prepared by dialkylation of thioamides.^[2] More commonly, they are prepared from derivatives of 2-aminoethanethiol (cysteamine).

Isomeric heterocyclic compounds: 2-thiazoline, 3-thiazoline and 4-thiazoline (from left to right). R is an organyl residue.

Related compounds

Three related classes of C₃NS heterocycles are well studied, 1,3-thiazoles (parent: C₃H₃NS), 1,3-thiazolines (parent: C₃H₅NS), and 1,3-thiazolidines (parent: C₃H₇NS). The naming is analogous to the C3N2 heterocycles, imidazoles, imidazolines, and imidazolidines.

Substituted thiazolines

Many molecules contain thiazoline rings, one example being luciferin, the light-emitting molecule in fireflies. The amino acid cysteine is produced industrially from substituted thiazole.^[3]

Thiazolines found in nature

In a recent study, thiazolines were identified in nature through an analysis of sesame seed oil. The toasted sesame seed oil was extracted using a Solvent-Assisted Flavor Evaporation technique. The extract was analyzed by GC and GC-MS and a total of 87 components were identified. Amongst these components, 2-ethyl-4-methyl-3-thiazoline and 2-isopropyl-4-methyl-3-thiazoline were identified and confirmed as being present in a natural product for the first time.^[4]

References

1. Walsh, Christopher T.; Nolan, Elizabeth M. (2008). "Morphing peptide backbones into heterocycles". Proceedings of the National Academy of Sciences USA 105: 5655–5656. doi:10.1073/pnas.0802300105.
2. Willstätter, Richard; Wirth, Theodor (1909). "Über Thioformamid". Chem. Ber. 42: 1908–1922. doi:10.1002/cber.19090420267.
3. Gaumont, Annie-Claude; Gulea, Mihaela; Levillain, Jocelyne (2009). "Overview of the Chemistry of 2-Thiazolines". Chem. Rev 109: 1371–1401. doi:10.1021/cr800189z.
4. Agyemang, D.; Bardsley, K.; Brown, S.; Kraut, K.; Psota-Kelty, L.; Trinnaman, L. (2011). "Identification of 2-Ethyl-4-Methyl-3-Thiazoline and 2-Isopropyl-4-Methyl-3-Thiazoline for the First Time in Nature by the Comprehensive Analysis of Sesame Seed Oil". J. Food Sci. 76: C385–C391. doi:10.1111/j.1750-3841.2011.02071.x.