The chloride ion catalysed addition of SCl2 to TCNE gives the dicyanomethyl
ene-1,2,6-thiadiazine 3 as major product together with two unexpected minor
products, pyrimidine 4 and pyrroloimidazothiadiazine 5, whose X-ray crysta
l structures are described; the products are derived from interaction of SC
l2 with one cyano group with neighbouring group participation by two others
.