Joseph Sisko

Development of a general process for the synthesis of highly substituted imidazoles

Several highly substituted imidazoles have been under investigation at GlaxoSmithKline as potential therapies for the treatment of rheumatoid arthritis and have spawned the need for a general synthetic method for their preparation on a multikilogram scale. We describe herein the optimization of a general method for the preparation of aryl-substituted TosMIC reagents and the ease with which they undergo [3+2] cycloadditions with a host of imines, prepared in situ, to generate densely functionalized imidazoles with various substitution patterns in a completely regioselective manner.

A convenient synthesis of trisubstituted pyrido[2,3-d]pyrimidin-7-ones

A novel, highly efficient and scalable route for the synthesis of trisubstituted pyrido[2,3-d]pyrimidin-7-ones was developed. The target compounds were synthesized in five steps from readily available reagents in about 40% overall yield.

Synthesis of fused dihydropyrano(furano)pyridines via [4 + 2]-cycloaddition of 5-alkenoxy substituted oxazoles.

A three-step procedure to access fused pyridines has been developed utilizing inexpensive amino acids and alkenols to form the key oxazole precursors. Yields are good to excellent and provide a rapid and inexpensive route to a range of pharmacologically and biologically valuable fused pyridines with difficult to access substitution patterns.