Mechanistic insight into the thermal 1,3-chlorine migrations of N-chloroacetanilides under neutral conditions

GRAPHICAL ABSTRACT

ABSTRACT

The mechanistic insight of the thermal 1,3-chlorine migration reactions of N-chloroacetanilides under neutral conditions has been investigated. The results indicate that the 1,3-chorine migration reaction is initiated by the radical reaction of the homocleavage of the Cl-N bond and subsequent radical combination of the Cl-C bond on the aromatic rings. The radical mechanism was verified by the thermal rearrangement of N-chloro-N-(4-methylphenyl)acetamide in cumene. After generation of hydrochloric acid in the radical mechanism, the migrations occurred through the acid-catalyzed rearrangement as well as the acid-catalyzed Orton reaction. The current results provide a comprehensive understanding on the mechanistic insights in the Orton reaction under different conditions.

KEYWORDS:

• Acetamide
• chloro shift
• mechanism
• Orton reaction
• thermal rearrangement

Funding

This work was supported in part by the National Basic Research Program of China (No. 2013CB328905), the National Natural Science Foundation of China (Nos. 21372025 and 21572017).