The electron impact‐induced cyclization of o‐carboxy‐ and o‐carboxamidocyclopropylbenzenes

Abstract

The isomerization of M + ' of o-carboxy-and o-carboxamidocyclopropylbenzenes into five-and six-membered heterocycles due to the ortho effect has been demonstrated by means of electron impact mass spectra, high-resolution mass spectrometry data and metastable ion spectra. The criteria for the quantitative estimation of the degree of cyclopropane cyclization into these isomeric cycles were formulated. The nature and quantity of heterocyclic ions proved to be in good accord with the results for cyclization of the same cyclopropanes in the strong acid solutions.

Cyclization of N‐arylcyclopropanecarboxamides into N‐arylpyrrolidin‐2‐ones under electron ionization and in the condensed phase

“…The spectra obtained for several series of ortho ‐substituted cyclopropylbenzenes were used to confirm the presence of the predicted heterocycles in solution. The cyclization products of the molecular ions for these arylcyclopropanes were identical to those synthesized in the condensed phase …”

‘Tert‐amino effect’ induced by electron ionization and comparison with thermal reaction in solution

“…Certain analogies between mechanisms of chemical reactions in the gas phase and in solution have been known for a long time 1–10. Sometimes it is possible to correlate the behavior of charged species formed both in the gas phase (e.g., in the ion source of a mass spectrometer) and in liquid phases.…”

“…Sometimes it is possible to correlate the behavior of charged species formed both in the gas phase (e.g., in the ion source of a mass spectrometer) and in liquid phases. Therefore, in addition to its analytical applications, mass spectrometry can be used to predict possible transformations of some organic compounds in solution under conditions of thermolysis and photolysis,1,2 or of catalysis with acids3–7 and bases 8–10…”

Chemistry of heterocyclic compounds at the Department of Organic Chemistry, Chemical Faculty, M. V. Lomonosov State University. (Review)

“…The intensity ratios of the key peaks in the electron impact spectra of the cyclopropanes corresponded with an accuracy of 3-5% to the ratio of the isomeric products after the establishment of equilibrium in the solution [315]. Unfortunately, the establishment of thermodynamic equilibrium was an extremely slow process.…”