David A. Entwistle

Replacing dichloroethane as a solvent for rhodium-catalysed intermolecular alkyne hydroacylation reactions: the utility of propylene carbonate

Propylene carbonate is an excellent solvent for rhodium-catalysed intermolecular alkyne hydroacylation reactions, allowing a variety of β-S-aldehydes and alkynes to be combined in high yields, to deliver enone products. The effective use of propylene carbonate removes the need to employ dichloroethane as solvent.

Inhalation by Design: Novel Tertiary Amine Muscarinic M3 Receptor Antagonists with Slow Off-Rate Binding Kinetics for Inhaled Once-Daily Treatment of Chronic Obstructive Pulmonary Disease

A novel tertiary amine series of potent muscarinic M(3) receptor antagonists are described that exhibit potential as inhaled long-acting bronchodilators for the treatment of chronic obstructive pulmonary disease. Geminal dimethyl functionality present in this series of compounds confers very long dissociative half-life (slow off-rate) from the M(3) receptor that mediates very long-lasting smooth muscle relaxation in guinea pig tracheal strips. Optimization of pharmacokinetic properties was achieved by combining rapid oxidative clearance with targeted introduction of a phenolic moiety to secure rapid glucuronidation. Together, these attributes minimize systemic exposure following inhalation, mitigate potential drug-drug interactions, and reduce systemically mediated adverse events. Compound 47 (PF-3635659) is identified as a Phase II clinical candidate from this series with in vivo duration of action studies confirming its potential for once-daily use in humans.

Optimized glucuronidation of dual pharmacology β-2 agonists/M3 antagonists for the treatment of COPD

‘Inhalation by design’ concepts were developed to create novel dual pharmacology β-2 agonists-M3 antagonists, for the treatment of chronic obstructive pulmonary disorder. A key feature of this work is the combination of balanced potency and pharmacological duration with optimised glucuronidation through the incorporation of metabolically vulnerable phenols.