THE CHEMISTRY OF THALIMIDOMETHYL-4H-PYRIDO[4,3-E]-1,2,4-THIADIAZINE 1,1-DIOXIDES AND THEIR USE IN THE SYNTHESIS OF POTENTIAL CHOLECYSTOKININ GASTRIN RECEPTORS LIGANDS/

The synthesis of thalimidomethyl-4H-pyrido[4,3-e]-1,2,4-thiadiazine 1, 1-dioxides is described. The compound devoid of an alkyl or an aryl su bstituent in the 4-position gave access by hydrazinolysis to H-pyrido[ 4,3-e]-1,2,4-thiadiazin-3-yl)methylamine, a key intermediate in the sy nthesis of 3-arylcarboxamidomethyl-4H- and rylureidomethyl-4H-pyrido[4 ,3-e]-1,2,4-thiadiazine 1,1-dioxides. Saturation of the double bond of enzamidomethyl)-4H-pyrido[4,3-e]-1,2,4-thiadiazine 1,1-dioxide by mea ns of sodium borohydride led to yl)-2,3-dihydro-4H-pyrido[4,3-e]-1,2,4 -thiadiazine 1,1-dioxide. The original pyridothiadiazine dioxides were proposed as potential cholecystokinin/gastrin receptor ligands. In sp ite of a strong biological efficiency on CCK receptors, this work on p yridothiadiazine dioxides reports new practical aspects of the chemist ry and physicochemical properties of this unusual heterocyclic ring sy stem.