Abstract The rationalization of the synthesis of substituted analogs of megazol, a biologically active 5-nitroimidazole at position 4 of the imidazole ring, had led to the study of intermediate steps. The methylation by diazomethane of 2, 4-(5) dihalogeno-5-(4) nitroimidazole is regioselective leading to 2, 4-dihalogeno-1-methyl-5-nitroimidazole 2. On this compound 2, hard nucleophiles such as cyanide, methoxide or hydride anions react ...