Mannich-type condensation-cyclization reaction of 7-Hydroxy-4-methyl benzopyrones with formaldehyde and primary amines in toluene at reflux, benzopyrone[8,7-e][1,3]oxazine derivatives were created and confirmed by spectral analyses. Antimicrobial screening showed promising results against various bacterial & fungal strains. ADME (Adsorption Distribution Metabolism Excretion) assessment of these drugs was performed. Title compounds passed ADME evaluation and showed good absorption of drugs in cells.