137278-09-2Relevant academic research and scientific papers
Ring closure reaction of 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones to benzo[b]pyrimido[4,5-h]1,6-naphthyridine-1,3,6-triones
Khattab, Ahmed F. A.,Van Tinh, Dang,Stadlbauer, Wolfgang
, p. 151 - 156 (2007/10/02)
N-Substituted aminouracils (1) react with malonates by cyclocondensation to 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones (2), which give with triethylorthoformate and aniline 6-(phenylaminomethylene)-pyrido[2,3-d]pyrimidine-tetraone (3). Halogenation of 2a-d (with R2 = Me) with phosphorylchloride leads to 5,7-dichloro-pyrido[2,3-d]pyrimidine-2,4-diones (4) by cleavage of the methyl group at N-8, whereas Vilsmeier reaction of 2 affords 5-chloro-6-formyl derivatives (6), which cyclize with arylamines to give benzo[b]pyrimido[4,5-h]1,6-naphthyridines (9). Compounds 9 were obtained independently by animation of the tosylates 5 to the 5-arylamino compounds 8, and Vilsmeier formylation to yield 9. Johann Ambrosius Barth 1996.
PYRIDOPYRIMIDINES 4. SYNTHESIS AND SOME TRANSFORMATIONS OF OXO(HYDROXY)PYRIDOPYRIMIDINES
Burova, O. A.,Smirnova, N. M.,Pol'shakov, V. I.,Chernov, G. S.,Losev, G. A.,Safonova, T. S.
, p. 538 - 544 (2007/10/02)
The cyclization of 5-cyanoacetyl-6-aminouracils in acidic media was accomplished.The structures of the pyridopyrimidines obtaines and their properties are discussed.
