Synthesis of novel spiro[cyclopropane-indazole] derivatives via magnesium-mediated conjugate addition of bromoform

摘要

A novel series of a,2-dibromo-3-aryl-l'-phenyl-6'7-dihydrospiro[cyclopropane-1,5'-indazol]-4'(1'H)-ones derivatives were prepared in moderate to good yields by conjugate addition of bromoform to (E)-5-arylmethylene-1-phenyl-6,7-dihydro-1H-indazol-4(5H)-ones in the presence of magnesium under N,The structures of all the products were characterised by ~1H NMR, ~(13)C NMR, IR spectroscopy, elemental analysis and mass spectrometry.