Sur la synthèse de chloro-3 indolinones a partir de β-nitrostyrènes diversement substitués

When treated with acetyl chloride and ferric chloride in methylene chloride, at 0°, monosubstituted β-nitrostyrene derivatives such as 2,3 or 4-methyl, -chloro or -fluoro and 3-nitro-β-nitrostyrenes cyclize into the new corresponding 3-chloro-1,3-dihydro-2H-indol-2-one. Reaction with other metal chlorides such as aluminum chloride and titanium tetrachloride does not lead to these heterocyclic derivatives but only produces N-acetyl-N-hydroxy-α-chlorobenzeneacetamides and/or N-(acetyloxy)-α-chlorobenzeneethanimidoyl chlorides.