Thionyl Chloride

[7719-09-7] Cl2OS (MW 118.97) InChI = 1S/Cl2OS/c1-4(2)3 InChIKey = FYSNRJHAOHDILO-UHFFFAOYSA-N (chlorination of alcohols,2 carboxylic acids,3 and sulfonic acids;4 dehydration of amides;5 formation of imidoyl chlorides,6 sulfur-containing heterocycles,7 and the Vilsmeier reagent) Physical Data: 8 bp 76 °C; d 1.631 g cm−3. Solubility: sol ethers, hydrocarbons, halogenated hydrocarbons; reacts with water, protic solvents, DMF, DMSO. Form Supplied in: colorless to yellow liquid. Purification: impurities cause formation of yellow or red colors. Iron contamination can cause a black color. Fractional distillation, either directly9 or from triphenyl phosphite10 or quinoline and linseed oil,11 has been recommended. Handling, Storage, and Precautions: very corrosive and reactive; the vapor and liquid are irritating to the eyes, mucous membranes, and skin. Protective gloves should be worn when handling to avoid skin contact. Thionyl chloride should be stored in glass containers at ambient temperature and protected from moisture. It reacts with water to liberate the toxic gases HCl and SO2. Since most reactions using SOCl2 evolve these gases, they should be performed only in well-ventilated hoods. Above 140 °C, SOCl2 decomposes to Cl2, SO2, and S2Cl2. Iron and/or zinc contamination may cause catastrophic decomposition.12