Possible approaches to the synthesis of functionalized, pyrazole, isoxazole, pyrimidine, pyridine and fused pyridine derivatives The sequence involves the heterocyclization of ethyl 3-oxo-2-(4-stearamidobenzoyl)butanoate (3) with appropriate reagents. Propoxylated of these heterocycles using propylene oxide to produce nonionic surface active agents having a long alkyl chain with molecular weight suitable for becoming an amphiphilic molecule with correct hydrophilic-lypophilic balance which enhances solubility, biodegradability and hence lowers the toxicity to human beings and becomes environmentally friendly. The antimicrobial activity of the newly synthesized was examined and it was found that some of these compounds have similar or higher activity compared with commercial antibiotic drugs (sulphadiazine), which make them suitable for diverse applications like the manufacturing of drugs, pesticides, emulsifiers, cosmetics, etc.