1,3,5,2,4-Trithiadiazines; a new ring system

Diazoalkanes react with tetrasulphur tetranitride to give red crystalline, 1,3λ4δ2,5,2,4-trithiadiazines [(3), (7), (8)], representatives of a new ring system with a nearly planar S3N2 unit; the parent compound (3) was independently synthesised from methanebis(sulphenyl chloride)(11) and sulphur bis(trimethylsilyl)diimide (12).