Abstract A new and environmentally benign protocol was developed for the synthesis of a series of benzylamino coumarin derivatives via the multicomponent reactions of 4-hydroxycoumarin, aromatic aldehyde and cyclic secondary amine in water using sulfated titania (TiO2-SO42−) as a heterogeneous solid acid catalyst under microwave irradiation at 100°C. The proposed method is advantageous due to its simple reaction procedure, high yield, easy work-up, short reaction time, and reusability of sulfated titania (TiO2-SO42−) and its high adaptability for the synthesis of benzylamino coumarin derivatives in good to excellent yields. The catalyst can be easily recovered and reused with almost the same catalytic activity. The structure of the benzylamino coumarin derivatives was confirmed by melting points, elemental analysis, IR, 1H, and 13C NMR and 2D NMR spectral data. Higher catalytic activity of sulfated titania (TiO2-SO42−) is due to its increased Bronsted acidity.

中文翻译：

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TiO2-SO42−：一种可回收的多相催化剂，用于在水中微波介导合成苄氨基香豆素衍生物

摘要 使用硫酸化二氧化钛 (TiO2-SO42−) 作为多相固体酸，通过 4-羟基香豆素、芳香醛和环状仲胺在水中的多组分反应，开发了一种新的环境友好型方案，用于合成一系列苄氨基香豆素衍生物。催化剂在 100°C 的微波辐射下。该方法具有反应过程简单、收率高、易于后处理、反应时间短、硫酸化二氧化钛（TiO2-SO42−）可重复使用等优点，以及对苄氨基香豆素衍生物合成的高度适应性。产量。该催化剂可以很容易地回收和重复使用，并且具有几乎相同的催化活性。苄氨基香豆素衍生物的结构通过熔点、元素分析、IR、1H、和 13C NMR 和 2D NMR 光谱数据。硫酸化二氧化钛 (TiO2-SO42-) 的更高催化活性是由于其增加的布朗斯台德酸度。