One-pot synthesis of highly functionalized pyrimido[1,2-b]indazoles via 6-endo-dig cyclization

An efficient synthesis of nitrogen ring junction pyrimido-indazoles has been developed. This is a metal catalyzed transformation that proceeds via A 3 coupling reaction between 1 H -indazol-3-amine, aromatic aldehydes and alkynes, which undergoes 6- endo -dig cyclization leading to the highly functionalized pyrimido[1,2- b ]indazoles. Response surface methodology (RSM) was used to investigate the effect of catalyst ( A 1 ), reaction temperature ( B 1 ) and time ( C 1 ). The fluorescence quantum yields of the pyrimido[1,2- b ]indazoles were calculated.