2′-Aryl-2,5′-bibenzoxazoles: Synthesis, crystal structure and evaluation of cytotoxicity against cervical (HeLa) and liver (HepG2) cancer cell lines

• Published in: Journal of molecular structure 2022-10, Vol.1265, p.133386, Article 133386
• Main Authors: Thakral, Sumit, Kumar, Devinder, Rani, Suman, Kataria, Ramesh, Sagar, Poonam, Singhal, Nitin Kumar
• Format: Article
• Language: English
• Subjects: Benzoxazole; Bibenzoxazole; Cytotoxicity
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.133386

•Twenty-four 2′-aryl-2,5′-bibenzoxazoles (8a-8x) were synthesized in excellent yield.•The structure was established through FTIR, NMR, MS and by X-Ray crystallography.•Cytotoxicity against HeLa and HepG2 cancer cell lines was screened.•Compounds 8p, 8k and 8t displayed IC50 values 4.787, 9.611 & 10.68 µM against HeLa. A library of twenty-four 2′-aryl-2,5′-bibenzoxazoles (8a-8x) has been synthesized from 2-arylbenzoxazole-5-carboxylic acids (6a-6d) which in turn are obtained by hydrolysis of methyl 2-arylbenzoxazole-5-carboxylates (5a-5d) in excellent yields. These carboxylates (5a-5d) are prepared form methyl 3-amino-4-hydroxybenzoate (3) and readily available various benzoic acids. The bibenzoxazoles (8a-8x) are characterised using NMR, FT-IR and HRMS techniques and the structure of 8h was established by X-ray crystallography. All the synthesized compounds (8a-8x) were screened for cytotoxicity (in vitro) against cervical cancer (HeLa) and hepato-carcinoma (HepG2) cell lines and non-cancerous (HEK293) cell line. Compounds, 8p, 8k and 8t shows good activity against HeLa cancer lines having the IC50 values 4.787, 9.611 and 10.68 µM, respectively.