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

Abstract

Diazoalkanes react with tetrasulphur tetranitride to give red crystalline, 1,3h462,5,2,4-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(sulpheny1 chloride) (11) and sulphur bis(trimethylsi1yl)diimide (12).

Planar 1,3λ4δ2,2,4-Benzodithiadiazine and Its Nonplanar 5,6,7,8-Tetrafluoro Derivative: Gas-Phase Structures Studied by Electron Diffraction and Ab Initio Calculations

“…Even though the S−N=S=N−S fragment is nearly planar, the values of the bond lengths quite clearly demonstrate that the π‐bonds are localized on N2, S3, and N4, since N2−S3 (1.549(3) Å) and S3−N4 (1.560(3) Å) are substantially shorter than S1−N2 (1.671(3) Å) and N4−S5 (1.668(3) Å). Similar differences in S−N bond lengths were observed in two derivatives of 9 ,24 that is, the 1‐oxo and the 6‐(4‐methoxyphenyl) derivatives. Despite the fact that the π‐bonds are localized in exactly the same way as in 1 and 2 , this cyclohexane‐type conformation is quite different from the folded structure found in 1 .…”

“…One of the basic members of this class of compounds is 1,3λ 4 δ 2 ,5,2,4‐trithiadiazine ( 9 );24 its structure is given in Scheme . The molecule exhibits a chair‐like (puckered envelope) conformation in the solid: the plane though S3, N2, and N4 and the plane through the carbon atom, S1, and S5 make angles of 4° and 48°, respectively, with the plane defined by the S1−N2 and N4−S5 bonds.…”

Organic heterocyclothiazenes. Part 12. 1,3,5,2,4-Trithiadiazines

“…3 In an attempted synthesis of trithiatriazepine (1) we treated S4N4 with diazomethane in the hope of introducing a methylene group into S4N4 followed by an aromatising loss of HNS. However trithiatriazepine was not formed in this reaction, but the product proved to be a new, six-membered ring, 1,3h4a2,5,2,4-trithiadiazine (2), 4 and we now give details of this route to trithiadiazines.…”

“…time scale. 4 The rapid reaction between diazomethane and S4N4 was studied in some detail, with variation in solvent, reaction temperature, and mole ratio and rate of mixing of the starting materials. These variables were optimised in di-, tri-, and tetrachloromethane, from 0 to 77 "C, by the single factor p r o c e d ~r e .…”

Organic heterocyclothiazenes. Part 13. Rational synthesis and chemistry of 1,3,5,2,4-trithiadiazines

“…Chlorinolysis of the pentathiepane (16),14 prepared from dithiolanes and dithianes confer a wide and interesting range of chemistry on these molecules, and by analogy we hoped to be able to generate the trithiadiazine cation (17) radical (18), and anion (19). If planar and delocalised, the cation would be an antiaromatic 87c, and the anion (19) an aromatic lox electron system.…”