STRUCTURE AFFINITY RELATIONSHIPS OF SOME ALKOXYCARBONYL-2H-PYRIMIDO OR ALKOXYCARBONYL-4H-PYRIMIDO [2,1-B]BENZOTHIAZOL-2-ONE OR 4-ONE BENZODIAZEPINE RECEPTOR LIGANDS

Synthesis and ability to displace [H-3]-diazepam binding from rat brai n membranes of the koxycarbonyl-4H-pyrimido[2,1-b]benzothiazol-4-ones 2a-h and koxycarbonyl-2H-pyrimido[2,1-b]benzothiazol-2-ones 3a-n are d escribed. It has been found that, among the prepared compounds, compou nd 2a is the most active. Structure-affinity relationships for compoun ds 2, 3 and the previously reported [16] koxycarbonyl-4H-pyrimido[2,1- b]benzothiazol-4-ones 1 are discussed. Moreover, theoretical molecular descriptors have been derived for such benzodiazepine receptor (BZR) ligands both from quantum chemical calculations (AM1) and modeling of their molecular structures. An attempt to interpret the obtained resul ts with reference to some BZR pharmacophore models is also reported.