A Facile Regioselective Synthesis of New Class of Cyclopent[b]indole dispiro heterocycles via1,3-Dipolar Cycloaddition protocol and invitro Cytotoxic studies

The construction of azomethine ylides insitu from acenaphthoquinone/isatin and secondary amino acids such as sarcosine and thiaproline with cyclopent[b]indole dipolarophilesin refluxing dioxane and methanol afforded novel class of cyclopent[b]indole dispiro heterocycles via 1,3-dipolar cycloaddition reaction. The regio and stereochemistry of formation of the final product was concertedly assigned by proton, carbon and 2DNMR techniques. Among the synthesized dispiroheterocyclic compounds 4&7 are found to show better cytotoxic activity against HeLa and MCF-7 with structure activity relationship (SAR) studies.