212131-74-3Relevant academic research and scientific papers
Pyrimidine annelated heterocycles-synthesis and cycloaddition of the first pyrimido[1,4]diazepine N-oxides
Heaney, Frances,Burke, Cathriona,Cunningham, Desmond,McArdle, Patrick
, p. 622 - 632 (2007/10/03)
5-Formyl- and 5-acetyl-4-(alkenylamino)pyrimidines 5 have been prepared as precursors to novel pyrimido[1,4]-diazepine N-oxides 3. In addition to cyclisation to the targeted dipoles the substrates 5 have also been observed to form imidazopyrimidines 12 and 39 via an intramolecular Michael addition; additionally 5b has been observed to form the pyrimidoazepinone 42. Aldonitrone 3a cycloadded readily to olefinic dipolarophiles; ketodipole 3b did not share this reactivity. Both dipoles reacted with acetylenic dipolarophiles but the ensuing cycloadducts 37 were unstable; facile ring contraction of their isoxazolopyrimidodiazepine skeletons to the pteridine nucleus is noted. The structure of 37c has been determined by X-ray crystallography.
Preparation of imidazo[1,2-c]pyrimidinones from a chloropyrimidine and an electron poor ω-allylic amine
Heaney, Frances,Bourke, Sharon,Burke, Cathriona,Cunningham, Desmond,McArdle, Patrick
, p. 2255 - 2257 (2007/10/03)
Synthesis of the title ring system by a sequential intermolecular nucleophilic displacement and intramolecular 'conjugate' addition has been achieved both as a one pot and as a stepwise procedure; an X-ray structure determination has been carried out to distinguish between the possible isomeric structures 8c-I and 8c-II.
