Hasan H.A.Abdulmalek E.Rahman M.B.A.Shaari K.B.Yamin B.M.Chan K.W.2024-05-282024-05-2820181752153X10.1186/s13065-018-0509-z2-s2.0-85059233791https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059233791&doi=10.1186%2fs13065-018-0509-z&partnerID=40&md5=0e6c6340e665a6e945b4841681e0df24https://oarep.usim.edu.my/handle/123456789/8725Background: Although the development of antibiotic and antioxidant manufacturing, the problem of bacterial resistance and food and/or cosmetics oxidation still needs more efforts to design new derivatives which can help to minimize these troubles. Benzimidazo[1,2-c]quinazolines are nitrogen-rich heterocyclic compounds that possess many pharmaceutical properties such as antimicrobial, anticonvulsant, immunoenhancer, and anticancer. Results: A comparative study between two methods, (microwave-assisted and conventional heating approaches), was performed to synthesise a new quinazoline derivative from 2-(2-aminophenyl)-1H-benzimidazole and octanal to produce 6-heptyl-5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazoline (OCT). The compound was characterised using FTIR, 1H and 13C NMR, DIMS, as well as X-ray crystallography. The most significant peak in the 13C NMR spectrum is C-7 at 65.5 ppm which confirms the cyclisation process. Crystal structure analysis revealed that the molecule grows in the monoclinic crystal system P21/n space group and stabilised by an intermolecular hydrogen bond between the N1-H1A.N3 atoms. The crystal packing analysis showed that the molecule adopts zig-zag one dimensional chains. Fluorescence study of OCT revealed that it produces blue light when expose to UV-light and its' quantum yield equal to 26%. Antioxidant activity, which included DPPH. and ABTS.+ assays was also performed and statistical analysis was achieved via a paired T-test using Minitab 16 software with P < 0.05. Also, the antimicrobial assay against two Gram-positive, two Gram-negative, and one fungus was screened for these derivatives. Conclusions: Using microwave to synthesise OCT have drastically reduced reaction time, and increased yield. OCT show good antioxidant activity in one of the tests and moderate antimicrobial activity.en-USABTSAntioxidantDihydrobenzo[4,5]imidazo[1,2-c]quinazolineDPPHSingle crystalArticle121145