A NOVEL SYNTHESIS OF A 1,3-DISUBSTITUTED 1,3-DIHYDRO-2H-IMIDAZO[4,5-b]PYRIDIN-2-ONE. APPLICATION TO GW808990 A CRF1 RECEPTOR ANTAGONIST

A novel synthesis of a 1,3-disubstituted 1,3-dihydro-2H-imidazo-[4,5-b]pyridin-2-one has been achieved by condensation of iminohydantoin 3 with t-butyl acetoacetate in diglyme at 160 °C. Hydrogenation of the product in the presence of 4-heptanone followed by a Buchwald-Hartwig amination afforded GW808990, a CRF 1 receptor antagonist.