ABSTRACT
Optimisation of a novel series of osteoclast ATPase inhibitors led to (2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6- pentamethylpiperidin-4-yl)-2,4-pentadienamide (1) that was the most potent compound in an in vitro osteoclast ATPase assay and in human bone resorption assays. Two of the possible geometric isomers have also been prepared and shown to be significantly less potent than 1.
Subject(s)
Enzyme Inhibitors/pharmacology , Osteoclasts/drug effects , Proton-Translocating ATPases/antagonists & inhibitors , Vacuolar Proton-Translocating ATPases , Enzyme Inhibitors/chemistry , Humans , Indoles/chemistry , Indoles/pharmacology , Isomerism , Osteoclasts/enzymology , Piperidines/chemistry , Piperidines/pharmacologyABSTRACT
In pyridazinone or thiadiazinone cardiotonic agents with one chiral centre, the PDE inhibitory action resides mainly in one enantiomer and the myofibrillar calcium sensitization mainly in the other. This phenomenon is observed when the chiral centre is located on the pyridazinone or thiadiazinone heterocycle, but cannot be extended to structures where the chiral centre is elsewhere on the molecule. For the first time a stereoselective synthesis of a 5-substituted 3,6-dihydro-6-methyl-2H-1,3,4-thiadiazine-2-one has been achieved and an absolute configuration is proposed.
