76698-22-1Relevant articles and documents
Cyclopropanimines, V. - Ring-substituted Cyclopropanimines from α-Bromoketimines
Quast, Helmut,Frank, Rolf,Heublein, Alfred,Schmitt, Edeltraud
, p. 1814 - 1835 (2007/10/02)
Good yields of N-alkyl- and N-arylcyclopropanimines 9 are obtained from the α-bromoketimines 8 in a 1,3-elimination of hydrogen bromide by means of an excess of potassium tert-butoxide in tetrahydrofuran.The α-bromoimine 14 forms the imine 15 derived from bicyclohexane.In part, the limitations of this 1,3-elimination can be traced back to an unsufficient acidity of the α'-protons of the α-bromoimines.All isolated cyclopropanimines are colorless, in vacuo distillable oils or low-melting crystals.Their stability parallels the size of the nitrogen subtituent.As shown by their 1H- and 13C-NMR spectra as well as the measurement of the ASIS and the temperature dependence of the 1H-NMR spectra the cyclopropanimines 9 exist as mixtures of (E,Z)-diastereomers.The (E)/(Z) ratio of the diastereomers increases with increasing size of the nitrogen substituent.According to its 13C-NMR spectrum, the bicyclohexanimine 15 prefers the boat conformation.The IR, UV, 1H-, and 13C-NMR spectra of the cyclopropanimines are compared to those of other heteromethylenecyclopropanes and of acyclic compounds.The main fragmentation paths in the mass spectrometer do not correspond to the thermal decomposition of the cyclopropanimines into isocyanides and alkenes.
