Facile Oxidation of fused 1, 4-dimethoxybenzenes to 1, 4-quinones using NBS: Fine-tuned Control over Bromination and Oxidation Reactions

DW Kim, HY Choi, KJ Lee, DY Chi

Index: Kim, Dong Wook; Choi, Han Young; Lee, Kee-Jung; Chi, Dae Yoon Organic Letters, 2001 , vol. 3, # 3 p. 445 - 447

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Citation Number: 47

Abstract

Fused 1, 4-dimethoxybenzenes could be oxidized to benzoquinones by either direct oxidation or demethylation-oxidation. The oxidative demethylation of 5, 8-dimethoxy-2- methylquinoline using 1.1 equiv of NBS in aqueous THF and a catalytic amount of H2SO4 at 20° C for 5 min gave 2-methylquinoline-5, 8-dione in 98% yield without bromination. Moreover, we can control either bromination or oxidative demethylation, or both reactions.