Effective chlorination of 2,3,5,6-tetrachloropyridine to pentachloropyridine was realized under mild phase transfer conditions with carbon tetrachloride and 50% NaOH or solid K3PO4. Mechanistic study of this reaction indicated the possibility of an aromatic carbanionic intermediate. Hexachloroethane was established as a more selective electrophilic chlorination agent.
在温和的相转移条件下,用
四氯化碳和50%NaOH或固体K 3 PO 4实现了2,3,5,6-四
氯吡啶的有效
氯化为五
氯吡啶。该反应的机理研究表明存在芳族碳负离子中间体的可能性。建立了
六氯乙烷作为更具选择性的亲电
氯化剂。