Synthesis and Benzodiazepine Receptor Affinity of Derivatives of the New Tricyclic Heteroaromatic System Pyrido[3′,2′:5,6]thiopyrano[4,3‐c]pyridazin‐3(2H,5H)‐one.

Abstract

Pyrido[3',2':5,6]thiopyrano[4,3-c]pyridazin-3(2H,5H)-one. -The new tricyclic systems (VII) and (VIII) are obtained via condensation of thiopyranopyridinones (I) with glyoxylic acid (II) and reaction of the intermediate acid mixtures (III), (IV) and (V) with hydrazine or substituted phenylhydrazines (VI). The benzodiazepine receptor ligands display an affinity in the micromolar/submicromolar order, but they show a lower potency than the structurally related ligands in the benzothiopyranopyridazinone series. -(PRIMOFIORE*, G.; DA SETTIMO, F.; MARINI, A. M.; SIMORINI, F.; LA MOTTA, C.; TALIANI, S.; LANERI, S.; TRINCAVELLI, L.; MARTINI, C.; Arch. Pharm. (Weinheim, Ger.) 338 (2005) 2-3, 126-132; Dip. Sci. Farm., Univ. Pisa, I-56126 Pisa, Italy; Eng.) -H. Hoennerscheid 34-207