A novel Brønsted solid acid named poly(vinylpyrrolidonium) hydrogen phosphate ([PVP-H]H2PO4) has been prepared by using H3PO4 and poly(vinylpyrrolidone) as green and commercially available reagents. The prepared reagent was characterized using a series of techniques including Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, energy-dispersive X-ray analysis (EDAX), pH analysis, and Hammett acidity function. The mentioned solid acid with wide acidic functional group sites can be utilized as a highly efficient, heterogeneous, and reusable catalyst for preparation of 2-amino-3-cyano-5-oxo-5,6,7,8-tetrahydro-4H-benzopyrans using aldehydes, dimedone, and malononitrile. Also, this catalyst can be reused for several times without loss of catalytic activity.
一种新型布朗斯台德固体酸名为聚
乙烯基吡咯烷酮
磷酸氢盐([PVP-H]H2PO4),采用绿色且商业上可获得的试剂H3PO4和聚
乙烯基吡咯烷酮制备。制备的试剂通过一系列技术进行了表征,包括傅里叶变换红外光谱(FT-IR)、热重分析(TGA)、扫描电子显微镜(
SEM)、X射线衍射(XRD)分析、能散X射线分析(E
DAX)、pH分析和哈米特酸度函数。这种具有广
泛酸性功能团位的固体酸可作为高效、非均相和可重复使用的催化剂,用于醛、
双甲酮和
丙二腈制备2-
氨基-3-
氰基-5-氧-5,6,7,8-四氢-4H-苯并
吡喃。此外,该催化剂可多次重复使用而不会损失催化活性。