N-Chlorosuccinimide

[128-09-6] C4H4ClNO2 (MW 133.53) InChI = 1S/C4H4ClNO2/c5-6-3(7)1-2-4(6)8/h1-2H2 InChIKey = JRNVZBWKYDBUCA-UHFFFAOYSA-N (electrophilic α-chlorination of sulfides, sulfoxides, and ketones; preparation of N-chloroamines) Alternative Names: 1-chloro-2,5-pyrrolidinedione; NCS. Physical Data: mp 144–146 °C. Solubility: sol H2O; sl sol CCl4, benzene, toluene, AcOH; insol ether. Form Supplied in: white powder or crystals having a weak odor of chlorine when pure; widely available. Purification: the commercial reagent acquires a light yellow color and a rather strong odor of chlorine after long storage but is easily recrystallized from acetic acid: rapidly dissolve 200 g of impure sample in 1 L preheated glacial AcOH at 65–70 °C (3–5 min); cool to 15–20 °C to effect crystallization; filter through a Buchner funnel and wash the white crystals once with glacial AcOH and twice with hexane; dry in vacuo (>85% recovery). Analysis of Reagent Purity: the standard iodide–thiosulfate titration method is suitable. Handling, Storage, and Precautions: store under refrigeration and protect from moisture; acutely irritating solid, with toxic effects similar to those of the free halogens; avoid inhalation; use an efficient fume hood; perform all operations as rapidly as possible to avoid extensive decomposition of the reagent.