Theoretical insights into the enhancement of 1-Methyl-2,4,5-trinitroimidazole yield by exchanging of group introduction order

Abstract During the synthesis of 1-methyl-2,4,5-trinitroimidazole (MTNI), the product yield was affected by group introduction order. This phenomenon has not been explained in the reaction mechanism. In this paper, the DFT method was used to study the synthesis mechanism. For the nitration reaction, an N-H ⋯ O hydrogen bond was formed between the midazole ring and water molecule in the solution to promote the nitration reaction, so the nitration mechanism was affected by the introduction of methyl group at the N site. For the methylation reaction, the electrophilic attack of the methyl group was affected by the introduction of more electron-withdrawing nitro group.