Rhodanine

Not to be confused with rhodamine.

Rhodanine is a 5-membered heterocyclic organic compound possessing a thiazolidine core. It was discovered in 1877 by Marceli Nencki who named it "Rhodaninsaure" in reference to its synthesis from ammonium rhodanide (known as ammonium thiocyanate to modern chemists) and chloroacetic acid in water.^[3]

Rhodanine^[1]

Names
Preferred IUPAC name 2-Sulfanylidene-1,3-thiazolidin-4-one
Other names 2-Thioxo-4-thiazolidinone; 4-Oxo-2-thioxothiazoline
Identifiers
CAS Number	141-84-4 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL224633 Y
ChemSpider	1013337 Y
ECHA InfoCard	100.005.005
EC Number	205-505-1
KEGG	C07280
PubChem CID	1201546
UNII	7O50LKL2G8 Y
CompTox Dashboard (EPA)	DTXSID4026002
InChI InChI=1S/C3H3NOS2/c5-2-1-7-3(6)4-2/h1H2,(H,4,5,6) Y Key: KIWUVOGUEXMXSV-UHFFFAOYSA-N Y InChI=1/C3H3NOS2/c5-2-1-7-3(6)4-2/h1H2,(H,4,5,6) Key: KIWUVOGUEXMXSV-UHFFFAOYAP
SMILES O=C1NC(=S)SC1
Properties
Chemical formula	C3H3NOS2
Molar mass	133.18 g·mol−1
Density	0.868 g/cm−3[2]
Melting point	170 °C (338 °F; 443 K)[2]
Solubility in water	Soluble[2]
Solubility	Ethanol, dimethyl sulfoxide[2]
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H318
Precautionary statements	P264, P270, P280, P301+P312, P305+P351+P338, P310, P330, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Rhodanines can also be prepared by the reaction of carbon disulfide, ammonia, and chloroacetic acid, which proceeds via an intermediate dithiocarbamate.^[4]

Derivatives

Some rhodanine derivatives have pharmacological properties; for instance, epalrestat is used to treat diabetic neuropathy. However, most are promiscuous binders with poor selectivity; as a result, this class of compounds is viewed with suspicion by medicinal chemists.^[5][6][7] Differing academic opinions exist concerning the correct use of PAINS filters, the necessity of the experimental confirmations of such properties, and many useful features of rhodanine derivatives.^[8][9]