137320-24-2Relevant academic research and scientific papers
Reactions of uracils. 21. Zwitterionic heteropolycyclic uracils by a novel three-component reaction: Iminophosphorane, isocyanate, heteroarene
Wamhoff,Schmidt
, p. 6976 - 6984 (2007/10/02)
The novel three-component reaction of (uracil-6-ylimino)phosphorane 1, isocyanate 2, and (substituted) pyridines gives, in a one-pot procedure, a variety of new pyrido[1',2':3,4]pyrimido[4,5-d]pyrimidines 3-11. The zwitterionic ground state of these new ring systems is i.a. established by means of solvatochromism, Hammett correlations, NMR, and X-ray analysis. Replacement of the pyridine by isoquinoline and phthalazine gives access to the novel ring systems pyrimido[4',5':4,5]pyrimido[6,1-a]isoquinoline and -phthalazine, which are formed as dihydro derivatives (14, 15) or as zwitterions (13, 17), depending on the reaction conditions. Oxidative cleavage of the phthalazine 15 in nitrobenzene affords the pyrimido[4,5-d]pyrimidines 16.
Heterocondensed uracil betaines by three component reaction: Iminophosphorane, heteroarene, isocyanate
Wamhoff, Heinrich,Schmidt, Andreas,Nieger, Martin
, p. 4473 - 4476 (2007/10/02)
1,3-Dimethyl-6(triphenylphosphoranylideneamino)uracil 1 affords with pyridines and the isocyanates 2a-f in a novel type of a three component reaction pyrido[1,2-f]pyrimido-[4,5-d] pyrimidines 5a-h (X-ray analysis of 5a).
