Dual Roles of N,N-Dimethylformamide in Benzothiazoles Synthesis from N-Benzoyl-N′-(2,4,6-trichlorophenyl)thiourea

N,N-Dimethylformamide (DMF) is not only a common polar solvent in chemistry, but also a reaction reagent, a catalyst and a stabilizer. In this paper, a new reaction was found accidently where DMF acted as both solvent and catalyst. By dissolving N-benzoyl-N '-(2,4,6-trichlorophenyl)-thiourea (BAD) in DMF and evaporating the solvent slowly, single crystals were obtained but their composition was determined to be 2-benzoylamino-4,6-dichloro-benzothiazole (BTT) with DMF molecule (BTT-DMF), not BAD. The single crystals of BAD could be obtained by crystallization from the solvents of acetonitrile or ethanol. The crystal structures of BAD and BTT-DMF were measured and analysed. Based on the hydrogen bonding interactions in their crystal structures, a possible reaction mechanism was proposed. All in all, DMF is a really multifunctional chemical, it may still have other potential functions which are interesting and valuable to be developed. Graphic A new reaction was found by dissolving N-benzoyl-N '-(2,4,6-trichlorophenyl)-thiourea (BAD) in DMF and evaporation of the solvent slowly to grow single crystals.