S8‐Mediated Cyclization of 2‐Aminophenols/thiophenols with Arylmethyl Chloride: Approach to Benzoxazoles and Benzothiazoles |
| |
| Authors: | Dr Haifeng Gan Dazhuang Miao Qiang Pan Renhe Hu Xiaotong Li Prof Dr Shiqing Han |
| |
| Institution: | 1. College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, P. R. China;2. (+86)?25‐58139369;3. Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, CAS, Shanghai, P. R. China |
| |
| Abstract: | A metal‐free approach to benzazoles from arylmethyl chlorides and 2‐mercaptan/2‐hydroxyanilines using elemental sulfur as a traceless oxidizing agent has been developed. The reactions proceeded in good to excellent yields, exhibiting good functional groups tolerance and gram‐scale ability. A key mechanistic investigation indicated that the key intermediate trisulfide 6 , which was characterized by NMR, HRMS and crystal X‐ray crystallography, was separated in the reaction prior to the formation of the product. |
| |
| Keywords: | arylmethyl chlorides benzothiazoles benzoxazoles cyclization sulfur |
|
|
