Synthesis and antifungal evaluation of some 3-phenyl-2,5-disubstituted indoles derived from new ethyl-2-benzyl-2-[N-(aryl)hydrazono] ethanoates.

In connection with previous related works [1-6] we have now studied the reaction of ethyl alpha-benzyl-alpha-acetylethanoate (EBAE), as an aliphatic active C-H compound, with the diazonium salts of p-aminobenzoic acid (PABA), sulfanilamide (SA) and N,N-dimethylsulfanilamide (DSA), respectively. Ethyl 2-benzyl-2-[N-(aryl)hydrazono] ethanoates were the resulting substances (1-3). The synthesis of 4-6, namely 3-phenyl-2,5-disubstituted indoles, was carried out employing acidic indole ring closure reaction (Fischer indole synthesis) starting from 1-3. Because only 5 had a high antifungal potency its derivatives 7-10 were also prepared. But these derivatives were unfortunately found to be inactive. Structure elucidation of 1-10 were made by elemental analysis, IR, NMR and mass spectral data.