Kevin Neil Dack

A mild and selective C-3 reductive alkylation of indoles

In the presence of triethylsilane and trifluoroacetic acid, the reaction between indoles and aldehydes in dichloromethane at 0°C, results in good yields of C-3 reductively alkylated products. The transformation is most effective for the preparation of 3-(arylmethyl)indoles 6 from aromatic aldehydes.

Design of Potent and Selective Inhibitors to Overcome Clinical Anaplastic Lymphoma Kinase Mutations Resistant to Crizotinib.

Crizotinib (1), an anaplastic lymphoma kinase (ALK) receptor tyrosine kinase inhibitor approved by the U.S. Food and Drug Administration in 2011, is efficacious in ALK and ROS positive patients. Under pressure of crizotinib treatment, point mutations arise in the kinase domain of ALK, resulting in resistance and progressive disease. The successful application of both structure-based and lipophilic-efficiency-focused drug design resulted in aminopyridine 8e, which was potent across a broad panel of engineered ALK mutant cell lines and showed suitable preclinical pharmacokinetics and robust tumor growth inhibition in a crizotinib-resistant cell line (H3122-L1196M).

Dynamic combinatorial mass spectrometry leads to inhibitors of a 2-oxoglutarate-dependent nucleic acid demethylase.

2-Oxoglutarate-dependent nucleic acid demethylases are of biological interest because of their roles in nucleic acid repair and modification. Although some of these enzymes are linked to physiology, their regulatory roles are unclear. Hence, there is a desire to develop selective inhibitors for them; we report studies on AlkB, which reveal it as being amenable to selective inhibition by small molecules. Dynamic combinatorial chemistry linked to mass spectrometric analyses (DCMS) led to the identification of lead compounds, one of which was analyzed by crystallography. Subsequent structure-guided studies led to the identification of inhibitors of improved potency, some of which were shown to be selective over two other 2OG oxygenases. The work further validates the use of the DCMS method and will help to enable the development of inhibitors of nucleic acid modifying 2OG oxygenases both for use as functional probes and, in the longer term, for potential therapeutic use.

Acidic triazoles as soluble guanylate cyclase stimulators

A series of acidic triazoles with activity as soluble guanylate cyclase stimulators is described. Incorporation of the CF(3) triazole improved the overall physicochemical and drug-like properties of the molecule and is exemplified by compound 25.

Thromboxane modulating agents. 1. Design of 1-[(arylsulfonyl)amino] alkylindole derivatives as dual thromboxane synthase inhibitor/thromboxane receptor antagonists.

Abstract The design of a series of dual thromboxane synthase inhibitor/thromboxane receptor antagonists based on an indole thromboxane synthase inhibitor template is described. The indole-5-propanoic acid derivatives 17, 22 and 23 were found to be potent dual agents in vitro.

Thromboxane modulating agents. 2. Thromboxane receptor antagonists derived from the thromboxane synthase inhibitor dazmegrel.

Abstract The design of dual thromboxane synthase inhibitor/thromboxane receptor antagonists (e.g. 15 ) based on the structure of the thromboxane synthase inhibitor dazmegrel is described. More potent receptor antagonists (e.g. 16c ) result from replacement of the pyridinyl subsituent with 4-fluorophenyl. Modelling suggests the existence of more than one site capable of interacting with the aryl sulfonamide of TxA 2 receptor antagonists.

Discovery of PF-184563, a potent and selective V1a antagonist for the treatment of dysmenorrhoea. The influence of compound flexibility on microsomal stability

The V1a receptor has emerged as an attractive target for a range of indications including Raynauds disease and dysmenorrhoea. As part of an effort to discover a new class of orally active V1a antagonist, we optimised a highly lipophilic, metabolically unstable lead into a range of potent, selective and metabolically stable V1a antagonists. In this communication, we demonstrate the series-dependent effect of limiting the number of rotatable bonds in order to decrease Cytochrome P450-mediated metabolism. This effort culminated in the discovery of PF-184563, a novel, selective V1a antagonist with excellent in vitro and in vivo properties.

Optimisation of a pyrazole series of progesterone antagonists; Part 1.

The design and synthesis of a novel series of non-steroidal progesterone receptor antagonists is described. Ligand-lipophilicity efficiency (LLE) was used in the selection of a prototype agent for in vivo pharmacology studies.

Thromboxane modulating agents. 4. Design and synthesis of 3-(2-[{(4-chlorophenyl)sulfonyl}-amino]ethyl)benzenepropanoic acid derivatives as potent thromboxane receptor antagonists

The design of a series of thromboxane receptor antagonists based on 3-(2-[[(4-chlorophenyl)sulfonyl]amino]ethyl)benzenepropanoic acid (1) is described. Addition of an arylmethyl group at the 5-position of 1 gave exceptionally potent agents in vitro and in vivo, with 13a (UK-147,535) giving complete blockade of the TxA2 receptor for greater than 12 hours in dogs, following an oral dose of 0.1 mg/kg.

Use of libraries to access new chemical space: Applications to CRTH2

The generation of novel CRTH2 ligands in heavily congested chemical space, by de novo design of libraries is disclosed. Novel (1719) compounds across seven libraries were synthesised. More than 100 of these compounds showed binding potency <3 μM against CRTH2, with the most potent being 247 nM. These libraries produced novel series and demonstrated that this approach is a viable one.