N-Chlorosuccinimide

N-Chlorosuccinimide (NCS) is the organic compound with the formula C₂H₄(CO)₂NCl. This white solid is used for chlorinations.^[2] It is also used as a mild oxidant.^[3] NCS is related to succinimide, but with N-Cl in place of N-H. The N–Cl bond is highly reactive, and NCS functions as a source of "Cl⁺".

N-Chlorosuccinimide^[1]

Names
Preferred IUPAC name 1-Chloropyrrolidine-2,5-dione
Other names Chlorosuccinimide
Identifiers
CAS Number	128-09-6 Y
3D model (JSmol)	Interactive image
Abbreviations	NCS
Beilstein Reference	113915
ChEBI	CHEBI:53203
ChEMBL	ChEMBL2107513
ChemSpider	29129 N
ECHA InfoCard	100.004.436
EC Number	204-878-8
Gmelin Reference	122816
PubChem CID	31398
UNII	0FWP306H7X Y
CompTox Dashboard (EPA)	DTXSID2042199
InChI InChI=1S/C4H4ClNO2/c5-6-3(7)1-2-4(6)8/h1-2H2 N Key: JRNVZBWKYDBUCA-UHFFFAOYSA-N N InChI=1/C4H4ClNO2/c5-6-3(7)1-2-4(6)8/h1-2H2 Key: JRNVZBWKYDBUCA-UHFFFAOYAN
SMILES O=C1N(Cl)C(=O)CC1
Properties
Chemical formula	C4H4ClNO2
Molar mass	133.53 g·mol−1
Appearance	white solid
Density	1.65 g/cm3
Melting point	148 to 150 °C (298 to 302 °F; 421 to 423 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H314, H319, H335, H412
Precautionary statements	P260, P261, P264, P270, P271, P273, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P330, P337+P313, P363, P403+P233, P405, P501
Related compounds
Related Imides	Succinimide N-Bromosuccinimide N-Iodosuccinimide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis and selected reactions

NCS is produced from succinimide by treatment with Cl⁺ sources, such as sodium hypochlorite (bleach), and t-butylhypochlorite, and even chlorine.^[2]

Electron-rich arenes are readily monochlorinated by NCS. Aniline and mesitylene are converted to the respective chlorinated derivatives.^[2]

Related reagents

• N-Iodosuccinimide (NIS), the iodine analog of N-chlorosuccinimide.^[4]
• N-bromosuccinimide (NBS), the bromine analog of N-chlorosuccinimide.^[5]
• Other N-chloro compounds that are commercially available include chloramine-T, trichloroisocyanuric acid ((OCNCl)₃), 1,3-dichloro-5,5-dimethylhydantoin.^[2]

Further reading

• Delaney, Paul A.; R. Johnstone (1985). "Solvent effects in the chlorination of tetrahydrothiophens with N-chlorosuccinimide". Tetrahedron. 41 (18): 3845–3851. doi:10.1016/S0040-4020(01)91405-X.
• N-chlorosuccinimide has been employed as chlorinating agent in combination with visible-light photoredox catalysts in organic synthesis.^[6]