3-Methyl-1(3H)-isobenzofuranone → (3E)-3-(3-methyl-2-benzofuran-1(3H)-ylidene)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of oxindole (119 mg, 0.891 mmol) in THF (2.0 ml) cooled at 0° C. was added 1.0M LiHMDS/THF (1.78 ml). The mixture was stirred for 4 minutes at 0° C., then allowed to warm to room temperature for an additional 6 minutes. A solution of 3-methyl-2-benzofuran-1(3 H)-one (119 mg, 0.802 mmol) in THF (0.5 ml) was added, and the reaction was rapidly stirred for 1.5 hours. The reaction was quenched into 10% HCl aqueous solution (30 ml). The resulting mixture was stirred 5 minutes, and then extracted into EtOAc. The combined organic layers were washed with water, brine, dried with anhydrous Na2SO4, and rotary evaporated to a yellow oil. Upon standing at room temperature overnight a yellow crystalline solid formed from the yellow oil. The remaining oil was removed by pipet and the solid was recrystallized from EtOAc to produce (3E)-3-(3-methyl-2-benzofuran-1(3 H)-ylidene)-1,3-dihydro-2H-indol-2-one as a yellow solid (32 mg, 15%).

Provenance & Evidence