Nano α-Al<sub>2</sub>O<sub>3</sub>supported ammonium dihydrogen phosphate (NH<sub>4</sub>H<sub>2</sub>PO<sub>4</sub>/Al<sub>2</sub>O<sub>3</sub>): preparation, characterization and its application as a novel and heterogeneous catalyst for the one-pot synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-c]pyrazole derivatives
作者:Behrooz Maleki、Samaneh Sedigh Ashrafi
DOI:10.1039/c4ra07813f
日期:——
8-tetrahydrobenzo[b]pyrans and 6-amino-5-cyano-4-aryl-1,4-dihydropyrano[2,3-c]pyrazoles from the condensation of various aldehydes, malononitrile, and 1,3-dicarbonyl compounds (1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione) or 3-methyl-1-phenyl-2-pyrazoline-5-one, using NH4H2PO4/Al2O3 with good yields. The use of easily available catalyst, shorter reaction times, better yields, the simplicity of the reaction
为制备2-氨基-3-氰基-4-芳基-7,7-二甲基-5,6,7,8-四氢苯并[ b ]吡喃和6-氨基的简单,有效和环境友好的方法被开发出来。来自各种醛,丙二腈和1,3-二羰基化合物(1,3-环己二酮或5,5-二甲基)缩合的-5-氰基-4-芳基-1,4-二氢吡喃并[2,3- c ]吡唑-1,3-环己二酮)或3-甲基-1-苯基-2-吡唑啉-5-酮,使用NH 4 H 2 PO 4 / Al 2 O 3产量高。使用容易获得的催化剂,更短的反应时间,更好的产率,反应的简单性,非均相系统和容易的后处理是本方法的优点。催化剂的表征是通过FT-IR光谱,X射线衍射(XRD)技术,热分析(TG / DTG)和透射电子显微镜(TEM)进行的。