One-Pot Synthesis of Spiro-isobenzofuran Compounds via the Sequential Condensation/Oxidation Reaction of Ninhydrin with 4-Amino-1,2-naphthoquinones/2-Amino-1,4-naphthoquinones under Mild Conditions

摘要

A one-pot route for the synthesis of spiro-isobenzofuran compounds was developed via the condensation reaction of ninhydrin with 4-amino-1,2-naphthoquinones or 2-amino-1,4-naphthoquinones in acetic acid followed by the oxidative cleavage of the corresponding vicinal diols at room temperature. Various derivatives of spiro[benzo[g ]indole-2,1′-isobenzofuran]-3,3′,4,5(1H ) tetraones and spiro[benzo[f ]pyrrolo[2,3-h ]quinoxaline-2,1′-isobenzofuran]-3,3′(1H )-diones were synthesized in good to high yields. Moreover, further condensation of spiro[benzo[g ]indole-2,1′-isobenzofuran]-3,3′,4,5(1H )-tetraones with 1,2-diamines resulted in the new spiro-isobenzofuran compounds having phenazine rings in high yields.