Trithiazyl Trichloride

[5964-00-1] S3N3Cl3 (MW 244.6) InChI = 1S/Cl3N3S3/c1-7-4-8(2)6-9(3)5-7 InChIKey = QBQMTUMJJWPFDJ-UHFFFAOYSA-N (a reactive source of S-N and N-S-N units in one-pot syntheses of heterocycles, particularly isothiazoles and thiadiazoles;1 the reactive species may be the trimer 1 or the highly reactive monomer NSCl) Alternate Name: trithiazyl chloride; trichlorotrithiatriazine; the 'trimer'. Physical Data: pale-yellow, moisture-sensitive crystals, mp 91 °C, but mp varied between 89 and 98 °C. Solubility: soluble in CCl4, C6H6, PhMe, THF, CS2; solutions warmed to above 60 °C turn green owing to dissociation into NSCl. The trimer 1 reacts with H2O (violently) and with other hydroxylic solvents.2 Preparative Methods: it is not commercially available but can be prepared with caution by heating NH4Cl with S2Cl2, followed by chlorination of the initially formed salt S3N2Cl2.3 This chlorination can be performed more conveniently with excess of sulfuryl chloride.4 The reagent can be generated in situ (see below).5 Purification: by crystallization from dry CCl4, thionyl chloride, or sulfuryl chloride, but this is not usually necessary. Handling, Storage, and Precautions: care is needed because of its sensitivity to moisture and to heat. It is best prepared on a small scale (ca. 10 g) and stored in a glass container with an air-tight rubber septum. To dispose off residues from the S3N2Cl2 preparation, the commonly used bleach solution should be avoided since unreacted NH4Cl may be converted to explosive nitrogen trichloride; a safe alternative is to add solid sodium bicarbonate and leave in a well ventilated fumehood for a few days before washing with a large amount of water.