Microwave Mediated Synthesis, Characterisation and Biological activity of Certain New Mannich Bases of Isatin and Coumarin.

In the present study Schiff's bases of isatin were synthesized by condensation of the keto group of isatin with the 4-methyl coumarinyl-7-oxyacetic hydrazide. The N-mannich bases of the above Schiff's bases were synthesized by reaction of acidic imino group of isatin with formaldehyde and various primary or secondary amines. In this current study, microwave assisted parallel synthesis along with the conventional method was opted for synthesizing Schiff's and Mannich bases of isatin and their efficacies based on the percentage yield and consumption of time for synthesis by each method were compared. The compounds synthesized were screened against some selected gram (+)ve and gram (−)ve microorganisms and activities were compared with a standard antibiotic. Similarly the prepared compounds were also subjected for antifungal screening, where activities were compared with standard antifungal agent. The compounds synthesized were also evaluated for antioxidant activity and compared with standard drug (ascorbic acid). Antioxidant activity was done by DPPH method.