Isomeric Solid Enols on Ring- and Amide-Carbonyls of Substituted 2-Carbanilido-1,3-indandiones

Both isomeric enols on ring carbonyl (5b) and on amide carbonyl (6b) derived from N-p-methoxyphenyl-2-carbamido-1,3-indandione (4b) were
isolated, and their X-ray structures were determined. X-ray diffraction of the N-o,p-dimethoxy analogue indicated a disorder ascribed to the
presence of a 6:4 mixture of 5c and 6c. Calculation (B3LYP/6-31+G*) gave good agreement with observed geometries. The calculated energies
indicated that enols 6 are more stable by

从N-α-甲氧基苯基-2-羰基-1,3-吲哚二酮（4b）衍生的环羰基（5b）和酰胺羰基（6b）上的两种异构烯醇被成功分离，并对其X射线结构进行了测定。N-α,α-二甲氧基类似物的X射线衍射结果显示出一种无序状态，归因于5c和6c的6:4混合物的存在。采用B3LYP/6-31+G*计算方法得出的结果与观察到的几何结构高度一致。计算得到的能量表明，烯醇6在稳定性上更为优越。