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Synthesis of Spiropyrimidodiazepines and Spirodiazepinopurines by Tandem Nitroso‐ene/ Diels–Alder Reactions
Author(s) -
Zhang FangLi,
Vasella Andrea
Publication year - 2007
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200790238
Subject(s) - chemistry , ene reaction , tandem , intramolecular force , imine , nitroso , intermolecular force , molecule , crystal structure , nitroso compounds , stereochemistry , diels–alder reaction , medicinal chemistry , organic chemistry , catalysis , materials science , composite material
New spirocyclic heterocycles 8, 16, 19/20, 25, 27 , and 30 derived from pyrimido[4,5‐ b ][1,4]diazepin]‐8′(9′ H )‐one were synthesised by a tandem nitroso‐ene/ Diels–Alder reaction of 4‐(alkenoylamino)‐5‐nitrosopyrimides. The crystal structure of 16 was established by X‐ray analysis. It is characterised by four pairs of intermolecular H‐bonds linking every two molecules in the unit cell. Sequential imine reduction and intramolecular condensation of the C(4′) ‐(acylamino)‐pyrimido[4,5‐ b ][1,4]diazepines 27 and 30 led to the [1,4]diazepino[1,2,3‐ gh ]purines 28 / 29 and 31 , respectively.