4,5-Dichloro-1,2,3-dithiazolium chloride explained

4,5-Dichloro-1,2,3-dithiazolium chloride (Appel's salt) is an organosulfur compound. It is the chloride salt of the 4,5-dichloro-1,2,3-dithiazolium cation. It is a green solid that is poorly soluble in organic solvents.

Synthesis

The compound is obtained by the reaction of acetonitrile with sulfur monochloride. The initial phases of this reaction entail chlorination of the acetonitrile. The resulting dichloroacetonitrile undergoes cycloaddition with sulfur monochloride:^[1]

The cation is highly electrophilic. It hydrolyzes readily. Protic nucleophiles displace one chloride:^{[2] [3]}

The compound was discovered by Appel et al.^[4]

References

1. 10.1002/jhet.5570290306. Polysulfur-Nitrogen Heterocyclic Chemistry. 1992. Rees. Charles W.. Journal of Heterocyclic Chemistry. 29. 3. 639–651.
2. Book: 10.1002/047084289X.rn01113. 4,5-Dichloro-1,2,3-dithiazol-1-ium Chloride. Encyclopedia of Reagents for Organic Synthesis. 2009. Foucourt. Alicia. Chosson. Elizabeth. Besson. Thierry. 978-0471936237.
3. 10.1016/S0040-4020(01)89619-8. 4,5-Dichloro-1,2,3-dithiazolium chloride (Appel's Salt): Reactions with N-Nucleophiles. 1994. Cuadro. Ana M.. Alvarez-Buila. Julio. Tetrahedron. 50. 33. 10037–10046. 10017/3581. free.
4. 10.1002/cber.19851180430. Synthese und Reaktionen des 4,5-Dichlor-1,2,3-dithiazolium-chlorids. 1985. Appel. Rolf. Janssen. Heinrich. Siray. Mustafa. Knoch. Falk. Chemische Berichte. 118. 4. 1632–1643.