produced. Therefore, reaction of these Schiff's bases with primary or secondary amines with formaldehyde in ethanol at room temperature afforded the corresponding Mannich bases 13–14. The structures of all new compounds were confirmed using spectral analysis. Furthermore, most of the synthesized derivatives showed high efficiency for removal of Pb2+, Cd2+, Ca2+, and Mg2+ from aqueous solutions, as well
                                    一种高效、简单、一锅法的双 Mannich 反应合成环化 2-methyl-6-取代-6,7-dihydro-5 H-s -triazolo[5,1- b ]-1,3,5 -噻二嗪通过5-methyl-1 H-s -triazole -3-thiol ( 1 ) 与
甲醛和脂肪族
伯胺在
乙醇中在室温下反应,而与伯芳族胺,未环化的 3-methyl-1-((取代-产生
氨基)甲基)-1 H-s-三唑-5-
硫醇。在 Mannich 反应条件下,4-
氨基-3-甲基-s-三唑-5-
硫醇 ( 8 ) 仅在沸腾的
乙醇中或室温下与
甲醛反应得到 3-methyl-5,6-dihydro- s-三唑并[3,4- b ]-1,3,4-
噻二唑,不掺入仲胺。此外,化合物8与芳香醛在不同反应条件下反应后,生成了未环化的席夫碱。因此,这些席夫碱与
伯胺或仲胺与
甲醛在
乙醇中在室温下反应得到相应的曼尼希碱13-14。使用光谱分析