A clean, three-component and one-pot cyclo-condensation to pyrimidine-fused heterocycles

摘要

A simple, clean and three-component one-pot cyclo-condensation reaction of barbituric acids, aromatic aldehydes and 6-amino-uracils or 1H-pyrazol-5-amines for the synthesis of pyrido[2,3-d:6,5-d]dipyrimidines and pyrazolo[4',3':5,6]pyrido[2,3-d]pyri-midines in refluxing water is reported. This protocol includes some important aspects, such as the use of water as a "green" reaction medium, high atom economy and mild reaction conditions. Reaction of 6-amino-uracils with ninhydrine resulted in the formation of tetrahydroindeno[2',r:4,5]pyrorolo[2,3-d]pyrimidine-triones. These products were evaluated in vitro for their antibacterial activities. Most of the compounds have a narrow to good spectrum antimicrobial activity.