TLC Separation of Isomeric Diazinodithiins and Diazinyl Sulfides as the Smiles Rearrangement Products
The reactions of diazinodithiins 1, 5, and 9 with sodium methanethiolate in DMSO, followed by methylation with methyl iodide, proceed with or without the Smiles rearrangement to give isomeric diazinodithiins 4, 8, and 12 and diazinyl sulfides 2, 3, 6, 7, 10, and 11. The aim of this was to find TLC conditions to follow the rearrangement, to separate and identify thioazines 1–12. The retention parameter RF was measured and next calculated as separation factors ΔRF, RS, and α. The RF values were correlated with the dipole moments of thioazines 1–12 and the symmetry (C2h and C2v) of diazinodithiins 1, 4, 5, 8, 9, and 12.