5-Chloro-1-methyl-4-nitroimidazole (CMNI) is suitable for use in the rapid mix experiments to investigate the mechanism of anomalous radiosensitization of mammalian cells by CMNI.It may be used in the synthesis of 5-aryl-1-methyl-4-nitroimidazoles, via Suzuki coupling with arylboronic acids, catalyzed by dichlorobis-(triphenylphosphine)palladium(II), K2CO3and tetrabutylammonium bromide.