Studies on pyrimidine-annulated heterocycles: Synthesis and function of novel 9-substituted cyclohepta[b]pyrimido[5,4-d]furan-8,10(9H)-diones

A new short synthesis of 9-substituted cyclohepta[b]pyrimido[5,4-d]furan-8, 10(9H)-diones has been accomplished by the reaction of 3-methyl-, 3-butyl- , and 3-phenylbarbituric acids with 2-chlorotropone in an enolate-substitut ion process and subsequent dehydrative cyclization by using CF3CO2H. These novel compounds exhibited a strong function in oxidizing some alcohols unde r neutral and aerobic conditions to give an aldehyde or ketones in an autor ecycling process, while they are hydrogenated to mixtures of 5,7-, 1,7-, an d 3,7-dihydrocyclohepta[b]pyrimido[5,4-d]furan-8,10(9H)-dione derivatives.