Search

This paper reports a new method for the synthesis of 3-aminooxindole derivatives. Ethyl 2-( N -arylcarbamoyl)-2-iminoacetates, which can be prepared from the reaction of α-ethoxycarbonyl-α-bromo- N -phenylacetamides with sodium azide, were found to undergo Friedel–Crafts cyclization to afford 3-aminooxindoles in high yield by the catalysis of an acid such as BF 3 ⋅OEt 2 . α-Aryl-α-azido- N -arylamides, on the other hand, were transformed to 3-arylaminooxindoles via a tandem 1,2-aryl migration-dinitrogenation and cyclization by the action of triflic acid. As both ethyl 2-( N -arylcarbamoyl)-2-iminoacetates and α-aryl-α-azido- N -arylamides are easily accessible, the current reactions are expected to be practically useful in the synthesis of 3-aminooxindole derivatives. [ABSTRACT FROM AUTHOR]