Mannich bases are important compounds due to their wide range of biological and industrial applications. Schiff's and Mannich bases of isatin possess versatile activities like antimicrobial,antiviral,anticancer, antitubercular activities etc. References show heterocyclic compounds containing coumarin to exhibit activities such as antimicrobial, antiviral, antitubercular, antipyretic, antiinflammatory and antioxidant activities and isonoazid to be an excellent antitubercular agent. In the light of these interesting biological activities the present work was carried out with view of synthesizing some isatin based Mannich bases from coumarin and isoniazid. Nowadays microwave mediated synthesis has gained importance in organic synthesis. 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 structure of the compounds synthesised has been confirmed by IR, 1H NMR and mass spectral data.All the compounds were screened for antimicrobial and antioxidant activity.