Selective heterofunctionalization of kynurenic acid derivatives

The latest findings in the literature show that kynurenic acid and its analogues are potent drug candidates against numerous neurological diseases. In this article, kynurenic acid derivatives were treated with NaOCl and NaOBr solutions and yielded the corresponding 3-halogeno compounds. The reaction is fast and conducted under mild conditions, and the yields are efficient just like the previous methods available for the same transformation. These newly synthesized halogeno compounds can serve as starting materials for the synthesis of 3-aminokynurenic acid analogues by treating the 3-bromokynurenic acid analogue with NaN₃. The solvent effect of this reaction was also examined. These reactions are suitable for the synthesis of 3-heterosubstituted kynurenic acid analogues.