Preparation of pyrazolo[3',4':4,5]pyrido[2,3-d]pyrimidines by the intramolecular reaction of azomethine imines in a 2,4(1H,3H)-pyrimidinedione system

Article abstract of DOI:10.1055/s-1993-25819

A facile synthetic route to establish 6,8-dimethyl-3,3a,4,5-dihydro-2H-pyrazolo[3',4':4,5]pyrido[2,3- d]pyrimidine-7,9(6H,8H)-diones is described based on an intramolecular azomethine imine cyclization followed by dehydrogenation. The azomethine imine int