Metal-free synthesis of 2-substituted (N, O, C) benzothiazoles via an intramolecular C-S bond formation.
An efficient, economical, and convenient method was developed for the preparation of 2-substituted (N, O, C) benzothiazoles from N'-substituted-N-(2-halophenyl)thioureas, O'-substituted-N-(2-halophenyl) carbamothioates, or N-(2-halophenyl) thioamides via a base-promoted cyclization in dioxane without any transition metal. A one-pot variant combining the synthesis of the thiourea and the cyclization was also demonstrated. High yields were obtained, and a variety of functional groups were tolerated under these conditions. Transition-metal-free, mild reactive conditions, wide application scope, and shorter reaction times make this method superior to the reported methods for the synthesis of 2-substituted benzothiazoles and suitable for combinatorial format.
Feng
Enguang
E
The Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, PR China.
Huang
He
H
Zhou
Yu
Y
Ye
Deju
D
Jiang
Hualiang
H
Liu
Hong
H
D052160:Benzothiazoles / Q000138:chemical synthesis* / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D015394:Molecular Structure; D013237:Stereoisomerism
D052160:Benzothiazoles