α7 nicotinic acetylcholine receptor agonists are promising therapeutic candidates for the treatment of cognitive impairment. As a follow up of our internal medicinal chemistry program we investigated a novel series of α7 nAChR agonists. Starting from molecular docking studies on two series of molecules recently developed in our laboratories, an alternative scaffold was designed attempting to combine the optimal features of these previously identified urea and pyrazole compounds. Based on our previous SAR knowledge and on predicted drug-like properties, a small library was synthesized in parallel manner, affording compounds with excellent α7 nAChR activity, selectivity and preliminary ADME profile.
A practical and scalable route to the SMO antagonist SEN826 1 is described herein, including the discussion of an alternative approach to the synthesis of the target molecule. The optimized route consists of five chemical steps. A new and efficient access to the key intermediate 6 via the bisulfite–aldehyde complex was developed, significantly enhancing the yields and reducing costs. As a result, a synthetic procedure for preparation of multihundred gram quantities of the final product has been developed.
A practical and scalable route to the Wnt inhibitor SEN461 1 is described herein. The optimized route consists of nine chemical steps. The intermediates are solids and were isolated by filtrations. Critical reactions steps in the medicinal chemistry route were modified for an initial scale-up process, and as a result, we developed a synthetic procedure for the preparation of multihundred gram quantities of the final product. A further process development for the phase 1 clinical batch campaign is reported.
The TWEAK-Fn14 pathway is upregulated in models of inflammation, autoimmune diseases, and cancer. Both TWEAK and Fn14 show increased expression also in the CNS in response to different stimuli, particularly astrocytes, microglia, and neurons, leading to activation of NF-κB and release of proinflammatory cytokines. Although neutralizing antibodies against these proteins have been shown to have therapeutic efficacy in animal models of inflammation, no small-molecule therapeutics are yet available. Here, we describe the development of a novel homogeneous time-resolved fluorescence (HTRF)–based screening assay together with several counterassays for the identification of small-molecule inhibitors of this protein-protein interaction. Recombinant HIS-TWEAK and Fn14-Fc proteins as well as FLAG-TWEAK and Fn14-FLAG proteins and an anti-Fn14 antibody were used to establish and validate these assays and to screen a library of 60 000 compounds. Two HTRF counterassays with unrelated proteins in the same assay format, an antiaggregation assay and a redox assay, were applied to filter out potential false-positive compounds. The novel assay and associated screening cascade should be useful for the discovery of small-molecule inhibitors of the TWEAK-Fn14 protein interaction.
α7 Nicotinic acetylcholine receptors (α7 nAChR) represent promising therapeutic candidates for the treatment of cognitive impairment associated with Alzheimer's disease (AD) and schizophrenia. A medicinal chemistry effort around previously reported compound 1 (SEN15924, WAY-361789) led to the identification of 12 (SEN78702, WYE-308775) a potent and selective full agonist of the α7 nAChR that demonstrated improved plasma stability, brain levels, and efficacy in behavioral cognition models.
Both stereoisomer of hydroxyethylamine (HEA) and hydroxyethylsulfide (HES) transition-state isostere inhibitors of BACE-1 were synthesized. The syn-HEA epimer resulted always more active than the anti stereoisomer independently from the P-1 and the P-1' substituents. On the contrary, the anti epimer of the HES isostere resulted more active than the syn stereoisomer. The change of stereopreference was studied by molecular modelling.
Using a commercially available device for controlled introduction of hydrogen in a vial for reactions under microwave dielectric heating, we developed a protocol for the transformation of substituted pyridines into the corresponding piperidines. Complete reduction occurred in 40 minutes, or even less, on substrates that require 24-48 hours to be reduced under standard conditions. Moreover, the reduction proved to be as stereoselective as the corresponding reaction carried out at room temperature.
An efficient synthesis of a pyrrolo-azepine scaffold for the parallel preparation of an array of (oxo-pyrrolo-azepinyl)acetamides is described. The Stetter cyclisation of 1,3-cyclohexanedione with ethyl bromopyruvate was the key reaction in the assembly of a tetrahydrobenzofuran substrate which was submitted to a rapid transformation into a tetrahydroindole by microwave-assisted cyclocondensation in the presence of glycine. The carbonyl group was then stereoselectively transformed into the corresponding (Z)-oxime which gave the pyrrolo-azepinone by Beckmann rearrangement in the presence of polyphosphoric acid. Trimethylaluminium-mediated amidation gave the corresponding amides which were finally N-alkylated at the 5-position to give 52 diverse (pyrrolo-azepinyl)acetamides, showing an appreciable exploration of the chemical space around the central heterocyclic core. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A parallel synthesis of aryl azoles with neuroprotective activity is described. All compounds obtained were evaluated in an in vitro assay using a NMDA toxicity paradigm showing a neuroprotective activity between 15% and 40%. The potential biological target of the active compounds was investigated by extensive literature searches based around similar scaffolds with reported neuroprotective activity. The most interesting molecules active in the NMDA toxicity assay (3a and 2g) showed moderate but significant activity in the inhibition of the Site 2 Sodium Channel binding assay at 10 mu M. To confirm our hypothesis compounds 3a, c, f and 2g were tested in the Veratridine assay which is one of the excitotoxicity assays of revelance to NaV channels. The compounds tested showed an activity between 40% and 70%. The identification of neuroprotective small molecules and the identification of NaV channels as the potential site of action were the most important goals of this work. (c) 2007 Elsevier Ltd. All rights reserved.