Abstract New 4-substituted concave pyridines 1b− d have been synthesised as precursors to allow extension of the pyridine π-system. With the Sonogashira coupling as the key synthetic step, the 4-iodo pyridine 1c was coupled with phenylacetylene (11) to give 1g in 77% yield. Because of its conjugated π system, the new concave pyridine 1g has UV absorption maxima at λ max1= 286 nm and λ max2= 303 nm with ϵ max1= 43300 Lmol− 1 cm− 1 and ...
