78007-56-4Relevant academic research and scientific papers
Studies on Diazepines. XXVIII. Syntheses of 5H-1,3-Diazepines and 2H-1,4-Diazepines from 3-Azidopyridines
Sawanishi, Hiroyuki,Tajima, Kayoko,Tsuchiya, Takashi
, p. 4101 - 4109 (2007/10/02)
Photolysis of 2-unsubstituted (5a-f) and 2,4-disubstituted (5k, l) 3-azidopyridines in the presence of sodium methoxide resulted in ring expansion to give the 4-methoxy-5H-1,3-diazepines (8 and 18), presumably via the azirine intermediates 6 and 17 derived from the initially formed singlet 3-pyridylnitrenes by cyclization at the 2-position of the pyridine ring.On the other hand, in the photolysis of 2-substituted 3-azidopyridines (5g-j), the cyclization of the nitrenes occurred predominantly at the vacant 4-position giving rise to the 3-methoxy-2H-1,4-diazepines (13).Keywords--3-azidopyridine; photolysis; pyridylnitrene; ring expansion; 5H-1,3-diazepine; 2H-1,4-diazepine; azirine intermediate
Thermolyse von Oxazolin-5-onen, XI. N-Acylimine und Enamide durch Gasphasenpyrolyse von 4-Alkyl-2-oxazoline-5-onen
Jendrzejewski, Stefan,Steglich, Wolfgang
, p. 1337 - 1342 (2007/10/02)
On gas phase thermolysis 4-alkyl-2-oxazolin-5-ones 1 undergo CO elimination to yield N-acylimines 2, which rearrange into more stable enamides 3 if α-hydrogens are present.N-Acylimines (e.g. 2a) may be isolated in cases where the rearrangement is prevented by a quarternary C-atom.The 4,4-dialkylsubstituted oxazolinone 1o yields mixtures of N-acylimine 2o and enamide 3o, the amount of the latter increasing at higher pyrolysis temperatures.
