AbstractThe synthesis of the first dithieno[2,3‐b : 2′,3′‐e]‐1,4‐thiazine is described, this compound was prepared by condensation of 3‐thiophenethiol with methyl 2‐bromo‐3‐nitrothiophene‐5‐carboxylate followed by reduction, acylation, bromination with NBS and ringclosure with Cu, K2CO3 in nitrobenzene.A thieno‐1,4‐benzothiazine was prepared in the same way. These compounds were synthesized in order to study the suggested correlation between charge‐transfer complexes vs. physiological activity.