Regioselective Synthesis of 3,6-Disubstituted-2-aminoimidazo[1,2-a]pyridines.

A convenient synthesis of 3,6-disubstituted-2-aminoimidazo[1,2-a]pyridines 3 is described. A halogen–metal exchange study on building block 1 showed that use of i-propyl magnesium chloride is most effective for chemoselective functionalization at position 6. Further regiospecific metalation at position 3, followed by quenching with different electrophiles, afforded target compounds.