Synthesis And Biological Evaluation of Some New Quinazoline Derivatives

Abstract

Quinazolines have gained significant attention due to their diverse pharmacological activities, including anti-inflammatory, antimicrobial, analgesic, hypnotic, sedative, antifungal, antispasmodic, antidiabetic, anti-tubercular, CNS depressant, and anti-cancer properties. Recent studies indicate that quinazoline derivatives exhibit moderate activity against various cancer cell lines and HIV. Additionally, several research articles have documented their antihistaminic properties. Given the importance of these heterocyclic compounds in medicinal chemistry, we aim to synthesize novel substituted quinazolines, characterize the synthesized compounds using IR and ¹H-NMR spectral data, and evaluate their antibacterial activity.The synthesis involves preparing different substituted 2-methylquinazolines using various substituted anilines. Final derivatives are obtained through the condensation of these 2-methylquinazolines with substituted aromatic aldehydes. The resultant quinazoline derivatives were purified using appropriate solvents, yielding 40-65%. Thin Layer Chromatography (TLC) was performed with chloroform: ethyl acetate (7:3) as the eluent to confirm the attachment.
Melting points were determined using Thiele's tube in open capillaries and are reported uncorrected. The purity of the compounds was assessed by TLC on silica gel G plates with chloroform: ethyl acetate (7:3) as the solvent system, visualized under UV light. IR spectra were recorded using KBr pellets on a Shimadzu 8000 series spectrophotometer. ¹H-NMR spectra were obtained on a Varian EM-200, 200 MHz spectrophotometer with DMSO as the solvent and TMS as the internal standard (chemical shift values are expressed in ppm).