The preparation of double salt of aluminum sulfate-sulfuric acid (Al4(SO4)6·(H2SO4)·24H2O) by the reaction of aluminum sulfate and sulfuric acid in water is described. Aluminum sulfate-sulfuric acid is characterized via some spectroscopic and microscopic techniques such as infrared spectroscopy (IR), X-ray diffraction spectroscopy (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) which corroborated the structure of the double salt. This double salt is soluble in water and insoluble in organic solvents. It was employed as a new catalyst for the synthesis of spirooxindole compounds on water with good to excellent yields. The double salt could be recycled and reused without appreciable loss of activity.

中文翻译：

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使用硫酸铝-硫酸复盐作为可重复使用的催化剂，“在水中”合成单和双螺吲哚衍生物。


介绍了硫酸铝与硫酸在水中反应制备硫酸铝-硫酸复盐(Al4(SO4)6·(H2SO4)·24H2O)的方法。硫酸铝-硫酸通过一些光谱和显微技术进行表征，例如红外光谱 (IR)、X 射线衍射光谱 (XRD)、能量色散 X 射线光谱 (EDX)、扫描电子显微镜 (SEM) 和透射电子显微镜显微镜（TEM）证实了复盐的结构。该复盐溶于水，不溶于有机溶剂。它被用作一种新型催化剂，用于在水中合成螺吲哚化合物，收率良好至优异。复盐可以回收和再利用，而不会明显损失活性。