Synthesis of Novel Spiro[Cyclopropane-Indazole] Derivatives Via Magnesium-Mediated Conjugate Addition of Bromoform

Abstract

A novel series of 2,2-dibromo-3-aryl-1′-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-1Hindazol-4(5H)-ones in the presence of magnesium under N 2 . The structures of all the products were characterised by 1 H NMR, 13 C NMR, IR spectroscopy, elemental analysis and mass spectrometry. IRKBr) ν max /cm -1 1686; MS (ESI) m/z 391 [M-Br] + . Anal. calcd for C 21 H 16 Br

Synthesis of novel dispiro[indazole-5,3′-pyrrolidine-2′,3″-indole] derivatives via 1,3-dipolar cycloaddition of azomethine ylide

“…The starting materials 1a-i were synthesised as previously described. 11 All of the reagents were from commercial suppliers and were used without further purification. All of the solvents were freshly distilled from the appropriate drying agents before use.…”

Synthesis of Spiro Indazole-Tetrahydrothiophenes via Sulfa-Michael/Aldol Cascade Reactions

“…Starting materials 1a-h were synthesised as previously described. 31 All of the reagents were from commercial suppliers and were used without further purification. All of the solvents were freshly distilled from the appropriate drying agents before use.…”