Synthesis and cellular cytotoxicities of new N-substituted indole-3-carbaldehyde and their indolylchalcones

A simple and efficient method for N-alkylation of indole-3-carbaldehyde derivatives using a mixture of different bases in DMF under conventional and microwave irradiation conditions to afford N-substituted indole-3-carbaidehyde derivatives 3a-o is reported. These derivatives which undergo Claisen-Schmidt condensation with 1-biphenyl-4-yl-ethanone yielded the corresponding indolylhalcone derivatives 5a-h. A comparative study showed that the microwave irradiation condition afforded excellent yield and shorten reaction time of all the synthesized indole derivatives which possess promising antitumor activity as well as interchelation bioactivity of indolylhalcones 5a-h with DNA.