Ring-Chain Tautomerism and Some Reactions of 2-Hydroxyindoline Derivatives

抄録

The spectral (proton and carbon-13 nuclear magnetic resonance) and chemical properties of the 1-acetyl-2-hydroxyindolines 1-5, which can exist in the ring (A) and chain (B) tautomers, have been investigated. The methylation and acetylation of the 2-hydroxy-3-indolinones 1-3 gave the ring tautomeric methyl ether and acetyl esters of 1-3, while the reaction with ο-phenylenediamine (9) gave the quinoxalines 10 and 11 as the chain tautomeric products. The reactions of 1-3 with the phosphonium ylide 12 gave the 2-methoxycarbonylmethyl-3-indolinones 14 (R = Ph) and 16 (R = Me) and/or the 2-hydroxy-3-methoxycarbonylmethyleneindolines 15 (R =Ph) and 18 (R = H), respectively, depending on the nature of the substituent (R) at the 2-position in 1-3. The acetylation and reaction of the 2, 3-dihydroxyindoline 4 with 12 are also described.