Indoxyl 1-acetyl

In 1883, the hydroxy structure 82 was assigned to indoxyl on the basis of chemical evidence. More recently, however, the infrared spectra of 1-acetyl- and 1-methyl-indoxyl measured in chloroform indicated that the oxo form 83 (R = Ac, Me) greatly predominates, " ... 

Synthesis of this compound began with the condensation of O, N-acetyl-indoxyl 174 with 5-bromoisatin 175 to give indolo [ 3,2-fo ] quinoline 176 after stirring at room temperature for 10 days (Fig. 49) [104]. This product was then decarboxylated by heating at reflux for 6 h in diphenyl ether. Yields were... 

It is possible to directly chloroacylate an aniline using chloroacetonitrile and boron trifluoride, ortho to the nitrogen. After (V-acylation, ring closure produces iV-acetyl-indoxyls. The Sugasawa synthesis of indoles utilises these same orf/to-chloroacetyl-anilines, via borohydride reduction and ring closure. ... 

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