Synthesis of novel ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives from 3-amino-4-carbamoyl-5-(methylthio)thiophene-2-carboxylate was carried out by traditional as well as microwave irradiation green protocol. Ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives were screened for antimicrobial screening against gram positive bacteria Staphylococcus aureus (ATCC 29737), gram negative bacteria Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (MTCC 277), Aspergillus niger (MCIM 545) fungi.