Iron-catalyzed synthesis of 4-arylpyrimido[1,2-b]indazoles using 3-aminobenzindazole, phenylacetylene, and N,N-dimethylformamide as one-carbon synthon

An iron-catalyzed [4 + 2] cyclization for constructing 4-Arylpyrimido[1,2-b] indazoles using 3-Aminopyrazole, phenylacetylene and N, N -Dimethylformamide has been reported, where N, N -Dimethylformamide (DMF) acted one-carbon synthon. The reaction conditions are mild and rapid, with a wide range of applicable substrates. • Employing DMF as a one-carbon synthon for efficient synthesis of 4-arylpyrimido[1,2-b] indazoles. • Extensive substrate range and favorable functional group tolerance. • Easily obtainable raw materials and fast reaction make it suitable for large-scale manufacturing. • Providing a new strategy for synthesizing biologically active molecules relevant to pharmaceutical research.