The indophenine reaction revisited. Properties of a soluble dialkyl derivative
摘要:
The classical indophenine reaction of thiophene with isatin and sulfuric acid has been reinvestigated using N-heptylisatin, which affords soluble reaction products amenable to chromatographic purification. An NMR analysis of the resulting indophenine blue (8) has shown it to be a mixture of all six possible geometric isomers (8a-f) of the previously assumed gross structure. The intermediacy of alcohol 11 in the formation of 8 is strongly supported. In addition, an indophenine analog (9a) derived from only one thiophene unit is reported for the first time.
The indophenine reaction revisited. Properties of a soluble dialkyl derivative
摘要:
The classical indophenine reaction of thiophene with isatin and sulfuric acid has been reinvestigated using N-heptylisatin, which affords soluble reaction products amenable to chromatographic purification. An NMR analysis of the resulting indophenine blue (8) has shown it to be a mixture of all six possible geometric isomers (8a-f) of the previously assumed gross structure. The intermediacy of alcohol 11 in the formation of 8 is strongly supported. In addition, an indophenine analog (9a) derived from only one thiophene unit is reported for the first time.