简介：Anefficientandenvironmentallyfriendlyprocedurefortheone-potsynthesisoftetrahydropyrimidinonesfromaldehydes,β-diketonesandurea/thioureabyusingmagnesiumbromideasaninexpensiveandeasilyavailablecatalystundersolvent-freeconditionswasdescribed.ComparedwiththeclassicalBiginellireactionconditions,thisnewmethodhastheadvantageofgoodtoexcellentyields(74%-94%)andshortreactiontime(45-90min).ThestructureoftheBiginellireactionproductfromβ-diketone,salicylaldehydeandureahasbeenproposedtopossessanoxygen-bridgebycyclization(intramolecularMichael-addition).

简介：为isoxazolo的合成的一个快速、有效的方法[5,4-d]pyrimidin-4(5H)在与固体的常规加热和没有溶剂的微波照耀下面与orthoesters通过5-aminoisoxazole-4-carboxamides的出租机动三轮车冷凝作用被开发了酸催化。在比较，反应更快，收益在微波照耀下面是更高的。

简介：4-(Succinimido)-1-butanesulfonicacidasanefficientandreusableBronstedacidcatalyzedthesynthesisofpyrano[4,3-b]pyranderivativesundersolvent-freeconditions.Thecatalystcanbepreparedbymixingsuccinimideand1,4-butanesultonethatismoresimpleandsaferthanthepreparationofsuccinimidesulfonicacid.Thismethodhastheadvantagesofhighyield,cleanreaction,simplemethodologyandshortreactiontime.Thecatalystcouldberecycledwithoutsignificantlossofactivity.