Heaney, Frances and Burke, Cathriona and Cunningham, Desmond and McArdle, Patrick (2001) Pyrimidine annelated heterocycles—synthesis and cycloaddition of the first pyrimido[1,4]diazepine N-oxides. Journal of the Chemical Society, Perkin Transactions 1 (6). pp. 622-632. ISSN 0300-922X

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Abstract

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 39via 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.

Item Type:	Article
Keywords:	Pyrimidine; annelated heterocycles; synthesis; cycloaddition; pyrimido[1,4]diazepine N-oxides;
Academic Unit:	Faculty of Science and Engineering > Chemistry
Item ID:	7973
Identification Number:	https://doi.org/10.1039/B007163N
Depositing User:	Dr. Frances Heaney
Date Deposited:	24 Feb 2017 16:28
Journal or Publication Title:	Journal of the Chemical Society, Perkin Transactions 1
Publisher:	Royal Society of Chemistry
Refereed:	Yes
Funders:	Enterprise Ireland (EI)
URI:	http://pubs.rsc.org
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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