SYNTHESIS AND CHARACTERIZATION OF HETEROAROMATIC CHALCONES

Abstract

Chalcones are well known naturally occurring pigments which serve as valuable intermediate in organic synthesis of flavonoid compounds. It has found significant role in pharmaceutical effects including antioncogenic, antiinflammatory, antiulcerative, analgesic, antiviral, antimalarial and antibacterial activities. Chloroquinoline and indole compounds are known to exhibit variety of antimicrobial activity. Also, it has been reported that chalcone having quinoline moiety is an intermediate for the synthesis of chloroquinoline cyanopyridines and cyanopyrans derivatives. Here an efficient method for quinoline and indole based chalcones synthesis described. 2- chloroquinoline aldehyde synthesized by using acylation of aniline followed by cyclization in presence of DMF/POC13 obtained quinoline aldehyde (2a) in 65% yield. Indole aldehyde synthesized accordingly "Vilsmayer reaction" by reacting indole with DMF/POC13 obtained Indole aldehyde (lb) 90 % yield. Indole based chalcones were synthesized accordingly Claisan-Shmidt condensation of indole aldehyde with various aromatic acetophenones by using piperidine as a base in ethanol obtained indole based chlacones (2b-7b) in 60-80% yield. Quinoline based chlacones also prepared accordingly Claisan-Shmidt condensation of 2-chloroquinoline aldehyde with various aromatic acetophenones by using 40 % aq NaOH as a base in ethanol obtained quinoline based chlacones (3a-8a) in 70-76 % yield.