5-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-2(1H)-quinolinones and 3,4-dihydro-2(1H)-quinolinones: dual-acting 5-HT1 receptor antagonists and serotonin reuptake inhibitors. Part 3.

5-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}-2(1H)-quinolinones and 3,4-dihydro-2(1H)-quinolinones have been identified with different combinations of 5-HT(1) autoreceptor antagonist and hSerT potencies and excellent rat PK profiles. The availability of tool compounds with a range of profiles at targets known to play a key role in the control of synaptic 5-HT levels will allow exploration of different pharmacological profiles in a range of animal behavioral and disease models.

Exploration of the amine terminus in a novel series of 1,2,4-triazolo-3-yl-azabicyclo[3.1.0]hexanes as selective dopamine D3 receptor antagonists.

A novel series of 1,2,4-triazol-3-yl-azabicyclo[3.1.0]hexanes with high affinity and selectivity for the DA D(3) receptor and excellent pharmacokinetic profiles was recently reported. We also recently discussed the role of the linker associated with the triazole moiety. In this manuscript, we are reporting a detailed exploration of the region of the receptor interacting with the amine terminus of the scaffold wherein SAR and developability data associated with these novel templates was undertaken.

Pyrrolo[1,2-a]pyrazine and pyrazolo[1,5-a]pyrazine: novel, potent, and selective series of Vasopressin 1b receptor antagonists.

Novel series of pyrrole-pyrazinone and pyrazole-pyrazinone have been identified as potent and selective Vasopressin(1b) receptor antagonists. Exploration of the substitution pattern around the core of these templates allowed generation of compounds with high inhibitory potency at the Vasopressin(1b) receptor, including examples that showed good selectivity with respect to Vasopressin(1a), Vasopressin(2), and Oxytocin receptor subtypes.

Design and synthesis of novel tricyclic benzoxazines as potent 5-HT(1A/B/D) receptor antagonists leading to the discovery of 6-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-4H-imidazo[5,1-c][1,4]benzoxazine-3-carboxamide (GSK588045).

Bioisoteric replacement of the metabolically labile N-methyl amide group of a series of benzoxazinones with small heterocyclic rings has led to novel series of fused tricyclic benzoxazines which are potent 5-HT(1A/B/D) receptor antagonists with and without concomitant human serotonin transporter (hSerT) activity. Optimizing against multiple parameters in parallel identified 6-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-4H-imidazo[5,1-c][1,4]benzoxazine-3-carboxamide (GSK588045) as a potent 5-HT(1A/B/D) receptor antagonist with a high degree of selectivity over human ether-a-go-go related gene (hERG) potassium channels, favorable pharmacokinetics, and excellent activity in vivo in rodent pharmacodynamic (PD) models. On the basis of its outstanding overall profile, this compound was progressed as a clinical candidate with the ultimate aim to assess its potential as a faster acting antidepressant/anxiolytic with reduced side-effect burden.

Cyclopenta[d]pyrimidines and dihydropyrrolo[2,3-d]pyrimidines as potent and selective corticotropin-releasing factor 1 receptor antagonists.

Two new classes of potent and selective CRF(1) receptor antagonists are presented. Exploration of general templates 3 and 4 through modifications of the top amine and bottom phenyl substituents led to optimization of the in vitro affinity and pharmacokinetic profiles. The typical alkyl chains present in the top region of CRF(1) antagonists were replaced by substituted heteroaryl moieties, leading to a dramatic improvement of the metabolic stability. This improvement was apparent when the compounds were dosed in vivo: several compounds exhibited low plasma clearance, good oral bioavailability, and high brain penetration. As a consequence of their outstanding pharmacokinetic profiles, these CRF(1) antagonists, as exemplified by compound 4 fi (4-(4-bromo-3-methyl-1H-pyrazol-1-yl)-7-(2,4-dichlorophenyl)-2-methyl-6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidine), produced a dose-dependent "anxiolytic-like" effect when administered orally, decreasing the vocalization of rat pups.

Diaryl substituted pyrrolidinones and pyrrolones as 5-HT2C inhibitors: synthesis and biological evaluation.

Within the continuous quest for the discovery of novel compounds able to treat anxiety and depression, the generation of a pharmacophore model for 5-HT2C receptor antagonists and the discovery of a new class of potent and selective 5-HT2C molecules are reported.

Enantiomerically pure tetrahydroquinoline derivatives as in vivo potent antagonists of the glycine binding site associated to the NMDA receptor.

To identify neuroprotective agents after stroke, new substituted tetrahydroquinoline derivatives were designed as antagonists of the glycine binding site associated to the NMDA receptor, satisfying the key pharmacophoric requirements. In particular, the racemate 3c exhibited outstanding in vivo activity in the MCAo model in rats, when given iv both pre- and post-ischemia. Pure enantiomers 3c-(+) and 3c-(-) have been prepared following an original synthetic route. Despite the significant difference of activity observed in vitro, they shown similar neuroprotective profile in the MCAo model in rats.

Benzoazepine derivative as potent antagonists of the glycine binding site associated to the NMDA receptor.

A series of benzoazepine derivatives, bearing suitable substituents at the C-3 position, was designed and evaluated by superimposition with the pharmacophore model of the glycine binding site. To fully explore the SAR of this class of compounds and to allow the preparation of new different compounds at the C-3 position, appropriate synthetic routes were set up. The benzoazepines were evaluated in terms of in vitro affinity using [3H]glycine binding assay and in vivo potency by inhibition of convulsions induced by N-methyl-D-aspartate (NMDA) in mice. This further analysis confirmed the preliminary results previously reported and that compound 27 is the most promising compound (Ki=32 nM, ED(50)=0.09 mg/kg, i.v.) in this series. Significant neuroprotective effect was observed after both pre- and post-ischaemia administration in the MCAo model. In particular, after post-ischaemia administration, it was found to be still effective when the administration was delayed up to 6 h after occlusion of the middle cerebral artery.

Solid-phase synthesis of combinatorial libraries based on enatiomerically pure (1S,2S,4R,5S)-4,5-dihydroxycyclohexan-1,2-dicarboxylic acid scaffolds.

The conditions for solid-phase functionalization of the new enantio-pure scaffold 1 to give libraries of general formula 4 have been derived.