The synthesis of chalcone has drawn tremendous interest over the past years due to its wide applications in the pharmaceutical and biological sectors. Indeed, this compound is reported to possess a broad spectrum of promising bioactivities, including anti-inflammatory, anti-invasive, antioxidant, antitumor and antibacterial properties. In this work, chalcone 3 was synthesised via Claisen-Schmidt condensation by using a common starting material of benzaldehyde 1 and acetophenone 2 in the presence of alcoholic alkaline base. Subsequently, 3,5-diphenyl-2-pyrazoline 4 intermediate was successfully synthesised by reductive amination reaction of 3 with hydrazine hydrate. Thereafter, insertion of acyl subunit at N-1 position of the corresponding amine via 1N-acylation reaction afforded the targeted 1-acetyl-3,5-diphenyl-1H-pyrazole 5 derivative. The structures of all the synthesised compounds were confirmed by elemental analyses, IR, GC-MS and NMR spectra.