Thiazoline

Thiazoline

Names
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
Identifiers
CAS Number	504-79-0 (2,3) Y 24576-55-4 (2,5) N 504-79-0 (4,5) N
3D model (JSmol)	(2,3): Interactive image (2,5): Interactive image (4,5): Interactive image
ChemSpider	133456 (2,3) 10541467 (2,5) 107368 (4,5)
PubChem CID	151424 (2,3) 15194654 (2,5) 120269 (4,5)
SMILES (2,3): C1=CSCN1 (2,5): C1=NCSC1 (4,5): C1CSC=N1
Properties
Chemical formula	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).
N  (what is YN ?)
Infobox references

Thiazolines (or dihydrothiazoles) are a group of isomeric heterocyclic compound 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.

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

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.

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.

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.