A new thermal process to prepare spiroindolin-3-ones from 3-substituted 2,1-benzisoxazoles in good yields (70–85%) is described. The highest yields were observed when microwave irradiation was used. The method does not require the use of any additive or catalyst. A possible reaction mechanism involving a nitrene key intermediate is proposed.

中文翻译：

---

由2,1-苯并异恶唑合成2-螺吲哚并-3-一（硫代）巴比妥酸酯：热条件促进的重排

描述了一种新的热方法，该方法可以由3取代的2，1-苯并恶唑制备高产率（70-85％）的螺吲哚啉-3-酮。当使用微波辐射时，观察到最高的产率。该方法不需要使用任何添加剂或催化剂。提出了一种可能的反应机理，其中涉及一个氮烯键中间体。