99747-54-3Relevant academic research and scientific papers
A facile synthesis of pyrrolo-[3,2-d]pyrimidines from 6-azidouracils and ylide phosphoranes
Abdou, Wafaa M.,Fahmy, Amin F. M.,Kamel, Azza A.
, p. 357 - 365 (2007/10/03)
A series of the title compounds, 9-deazaxanthines, was regioselectively prepared in reasonable yields as major products from the reactions of 6-azidouracils 1a,b with stabilized ester-2a,b or keto-2c ylide phosphoranes and a moderated phosphorus ylide 3, instead of the expected triazoles. Side products were also observed wherein pyrimido[5,4-g]pteridine-2,4,5,7-tetrone (15) and other fused ring systems or acyclic-substituted uracil derivatives were isolated. A comparative study on the reactivity of 1a in analogy to 1b toward phosphoranes is also described.
Pyrido[2,3-d]pyrimidines, II [1]. One Step Synthesis of Pyrido[2,3-d]pyrimidines and Pyrimido[4,5-b]quinolines from 6-Amino Uracils
Khattab,Kappe
, p. 917 - 925 (2007/10/03)
Reduction of 6-azidouracils 2 with hydrogen palladium or sodium dithionite afforded the corresponding 6-aminouracils 5 which could also be obtained by reaction of 2 with triphenylphosphane via phosphazenes and subsequent hydrolysis (Staudinger reaction). The use of trimethylphosphite instead of phosphanes yields with 2b the expected trimethoxyphosphazene 3c, whereas 2a reacts to the phosphonoaminopyrimidine 4. The syntheses of 5-hydroxy pyrido[2,3-d]pryimidine-2,4,7-triones 6, pyrido[2,3-d]pyrimidine-2,4,5-triones 8, cyclopenta[e]pyrido[2,3-d]pyrimidin-2,4,5-triones 7a, c, and tetrahydro-pyrimido[4,5-b]quinolin-2,4,5-triones 7b, d by condensation of 6-aminouracils 5 with malonates, ethylaceto/benzoylacetate, ethyl 2-oxocyclopentanecarboxylate and ethyl 2-oxocyclohexanecarboxylate, respectively, are described.
Reactions of Uracils. 6. New Ring Transformations of 6-Aminouracils with Acetylenedicarboxylates to Pyridinedionates and Pyrrolopyridines. Some Revised Constitutions
Wamhoff, Heinrich,Schupp, Winfried,Kirfel, Armin,Will, Georg
, p. 149 - 154 (2007/10/02)
Treatment of 6--1,3-dimethyluracils 8 with dialkyl acetylenedicarboxylates in aprotic solvents affords zwitterionic pyridinedionates 12, involving a novel ring transformation reaction, via cleaving attack of a terminal carbanion to the 2-carbonyl of the uracil.In protic solvents 12 undergo a smooth heterocyclization reaction to give the pyrrolopyridines 14.The structures of 12b and 14b have been established by single-crystal X-ray diffraction.By spectroscopic comparison as well as by independent syntheses 12 proved to be closely related (phosphorylated) analogues of previously reported "ureas 17 and 18", while 13 was identical with the "5-propynoyluracil 15".Catalytic hydrogenation of 13a gave carbinol 20, which proved by means of 1H (H-D exchange) and 13C NMR to be identical with "cis-olefin 19".
