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

Abstract

An efficient synthesis of nitrogen ring junction pyrimido-indazoles has been developed. This is a metal catalyzed transformation that proceeds via A³ coupling reaction between 1H-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 (A₁), reaction temperature (B₁) and time (C₁). The fluorescence quantum yields of the pyrimido[1,2-b]indazoles were calculated.