一锅法三组分合成苯并噻唑酮

Benzothiazolones represent an important class of compounds found in medicines and pesticides. The traditional synthetic methods to prepare of benzothiazolones usually suffered from the limitation of commercially available starting materials such as substituted o-aminothiophenols, toxic carbonyl sources or multiple steps. In this paper, an efficient Cu-catalyzed one-pot synthesis of benzothiazolones directly from easily available 2-haloanilines, potassium sulfide and N,N-dimethylformamide (DMF) as strating materials has been developed. In this protocol, C-S and C-N bond formation occurs during reactions with yields up to 87% after optimization of reaction conditions, which was CuSO4 (10 mol%), 2,2'-bipyridine (10 mol%), and NaOH (3 equiv) at 120 C for 18 h without inert atmosphere. Electron-donating groups seemed to be beneficial to the catalysis than electron-withdrawing groups, which indicated the electron-donating groups would benefit the nucleophilic attack during reaction. The mechanism studies revealed that the carbonyl group of product came from DMF.