Synthesis and properties of azoles and their derivatives. 23. Electron impact mass spectrometry of regio- and stereoisomeric diarylnitro-Δ2-isoxazolines
AbstractIt was shown that the general paths of dissociation of molecular ions of 3-phenyl-4(5)-aryl-5(4) nitro-δ2-isoxazolines involve the primary elimination of the NO2., HNO2, and OCHNO2 particles, and also the formation of the C6H5CN+., C6H5+, ions and substituted tropylium cations. The 3,5- and 3,4-diaryl isomers differ most sharply in the probability of formation of 
$$\left[ {{\text{RC}}_{\text{6}} {\text{H}}_{\text{4}} {\text{C}} \equiv \mathop {\text{O}}\limits^ + } \right]$$
 ions, the peaks of which are maximal in the first case. The mass spectra of cis- and trans-isomers in the 3,5-diarylisoxazoline series differ little quantitatively.