A new series of 2-(aryldiazenyl)-[1H]-3-methylbenzo[g] indoles were synthesized as potential antitumor agents by cyclization reaction of the corresponding arylamidrazones in the presence of polyphosphoric acid (PPA) as a cyclizing agent.
The later arylamidrazones were synthesized by reaction of their corresponding hydrazonyl chlorides with 1-naphthylamine in the presence of triethylamine (TEA) as a base. The starting hydrazonyl chlorides were prepared by diazotization reaction of the commercially available substituted aniline derivatives reacted with α-chloroacetylacetone in the presence of pyridine.
This novel strategy gives easy access for the synthesis of benzo[g]indoles. The newly synthesized compounds have been characterized by X-Ray, 1H NMR, 13C NMR and mass spectrometry