Comparison Study of Synthesis of some Aromatic Compounds Using Conventional and Microwave Method

Abstract

 In this study, four aromatic compounds—benzylidene aniline, acetanilide, and (N)-cinnamylidene aniline-benzimidazole—were prepared and their physical properties (Molecular weight, Melting point, Density, Solubility, Reaction time, and Yield). The conventional solvent method was evaluated for benzylidene aniline yielded 88% with a reaction time of 30 min, while the microwave method significantly improved the efficiency, producing a 97% yield in just 2 min, with no changes in melting point or density. Infrared spectra confirmed the presence of characteristic C–H, C=C, and C=N vibrations. For acetanilide, the conventional method yielded 86% in 20 min, while microwave irradiation increased the yield to 95% with a shorter reaction time of 3 to 5 min. The melting point and density were almost identical in both methods, confirming the purity of the product. Infrared spectral data supported the successful formation of acetanilide through the characteristic stretching vibrations of N–H, C–H, and C=O. For N-cinnamylidene aniline, the conventional solvent-based method achieved a yield of 77%, with a melting point between 175 and 176.5 °C and a density of 0.93 g/cm³. Vibrations were found at characteristic bands for the benzamidazole compound at 1620 cm⁻¹ (C=N) and 1600–1450 cm⁻¹ (aromatic C=C), the yield was 75% using the conventional method, while the yield was 91% using the microwave method, with a reduced time of only 15 minutes. The IR spectrum showed two peaks at 3400–3300 cm⁻¹ (N–H) and 1620–1600 cm⁻¹ (C=N), confirming the formation of the expected product. Overall, the results demonstrate that microwave-assisted synthesis outperforms conventional solvent-based methods, providing higher yields and shorter reaction times while maintaining similar physical and spectral properties of the final products.