Synthesis of druglike molecules for respiratory diseases: Utilizing microwave chemistry

Microwave-assisted organic synthesis, now ever-present in drug-discovery programs, is often reported with enhanced yields and reduced reaction times when compared with conventional heating. This is frequently coupled with a cleaner reaction profile and therefore more facile purification. At Novartis Institutes for Biomedical Research, in Horsham, UK, we research into new treatments for respiratory diseases and microwave-assisted chemistry is performed routinely within our laboratories. We have found that this form of heating significantly improves some reaction types, in particular, palladium-catalyzed processes such as Suzuki reactions. There is considerable literature in the use of microwaves to accelerate these types of palladium-catalyzed reactions. The following sections describe microwave reactions to prepare compounds that may be used to treat respiratory diseases which we, at Horsham, have found particularly interesting and offer genuine advantages over traditional thermal heating.