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Inhibition of the aspartyl protease BACE-1 has the potential to deliver a disease-modifying therapy for Alzheimer's disease. Herein, is described a series of potent inhibitors based on an hydroxyethylamine (HEA) transition state mimetic template. These inhibitors interact with the non prime side of the enzyme using a novel edge-to-face interaction with Arg-296.

Our first generation of hydroxyethylamine transition-state mimetic BACE-1 inhibitors allowed us to validate BACE-1 as a key target for Alzheimer's disease by demonstrating amyloid lowering in an animal model, albeit at rather high doses. Finding a molecule from this series which was active at lower oral doses proved elusive and demonstrated the need to find a novel series of inhibitors with improved pharmacokinetics. This Letter describes the discovery of such inhibitors.

Traditional strategies in indole chemistry do not allow high-yielding access to some substitution patterns such as 3,5,7-trisubstituted indoles. We report in this article the efficient synthesis of this type of indole. The Heck cyclisation strategy we used allows the synthesis of 7-iodo-, 7-alkoxy-, 7-amino-, and 7-nitroindoles bearing other functionalities at the 3- and 5-positions. We believe that the mild conditions used should allow the preparation of indoles with a wide range of substituents in these two positions as shown by the synthesis of a 5-bromo-7-iodoindole. However, this strategy has some limitations in the case of very electron-deficient indoles such as a 7-nitroindole where the aromatisation of the 7-nitrodihydroindole intermediate is not complete. In this case, Larock's indole synthesis from disubstituted acetylenes proved to be more appropriate.

Traditional strategies in indole chemistry do not allow high yielding access to some substitution patterns such as 3,5,7-trisubstituted indoles. We report in this article the efficient synthesis of this type of indole. The Heck cyclisation strategy we used allows the synthesis of 7-iodo-, 7-nitro-, 7-amino- or 7-alkoxy indoles bearing other functionalities in the 3- and 5-positions. We believe the mild conditions used should allow preparation of indoles with a wide range of substituents in these two positions.

The development of the collagenase inhibitor, cipemastat (Ro 32-3555), required the synthesis of both carbon-14 labelled and deuteriated material for the measurement of the parent drug and drug-related material in biological fluids. In addition, labelled metabolites were needed for both in vitro metabolism and analytical studies. This paper describes the synthesis of labelled forms of cipemastat and its amide (Ro 32-4778) and glucuronide (Ro 32-6414) metabolites. Copyright © 2001 John Wiley & Sons, Ltd.

Our first generation of hydroxyethylamine BACE-1 inhibitors proved unlikely to provide molecules that would lower amyloid in an animal model at low oral doses. This observation led us to the discovery of a second generation of inhibitors having nanomolar activity in a cell-based assay and with the potential for improved pharmacokinetic profiles. In this Letter, we describe our successful strategy for the optimization of oral bioavailability and also give insights into the design of compounds with the potential for improved brain penetration.

Inhibition of the aspartyl protease BACE-1 has the potential to deliver a disease-modifying therapy for Alzheimer's disease. We have recently disclosed a series of transition-state mimetic BACE-1 inhibitors showing nanomolar potency in cell-based assays. Amongst them, GSK188909 (compound 2) had favorable pharmacokinetics and was the first orally bioavailable inhibitor reported to demonstrate brain amyloid lowering in an animal model. In this Letter, we describe the reasons that led us to favor a second generation of inhibitors for further in vivo studies.

BACE-1 inhibition has the potential to provide a disease-modifying therapy for the treatment of Alzheimer’s disease. Optimization of a first generation of BACE-1 inhibitors led to the discovery of novel hydroxyethylamines (HEAs) bearing a tricyclic nonprime side. These derivatives have nanomolar cell potency and are orally bioavailable.

This paper describes the discovery of non-peptidic, potent, and selective hydroxy ethylamine (HEA) inhibitors of BACE-1 by replacement of the prime side of a lead di-amide 2 . Inhibitors with nanosmolar potency and high selectivity were identified. Depending on the nature of the P 1 ′ and P 2 ′ substituents, two different binding modes were observed in X-ray co-crystal structures.

This article is focusing on further optimization of previously described hydroxy ethylamine (HEA) BACE-1 inhibitors obtained from a focused library with the support of X-ray crystallography. Optimization of the non-prime side of our inhibitors and introduction of a 6-membered sultam substituent binding to Asn-294 as well as a fluorine in the C-2 position led to derivatives with nanomolar potency in cell-based assays.

Inhibition of the aspartyl protease BACE-1 has the potential to deliver a disease-modifying therapy for Alzheimer’s disease. Herein, is described the lead generation effort which resulted, with the support of X-ray crystallography, in the discovery of potent inhibitors based on a hydroxy ethylamine (HEA) transition-state mimetic. These inhibitors were capable of lowering amyloid production in a cell-based assay.