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Chemistry of Heterocyclic Compounds

, Volume 7, Issue 7, pp 892–893 | Cite as

Preparation of the simplest Δ1-pyrazolines by isomerization of Δ2-pyrazolines

  • B. V. Ioffe
  • N. B. Burmanova
Article

Abstract

Δ2-Pyrazolines that do not have substituants in the 1- and 3-positions are not capable of isomerization to 3-substituted pyrazolines and can be converted to Δ1-pyrazolines by slow distillation in the presence of bases. This method, which is completely analogous to the synthesis of azo compounds from alkylhydrazones, gives good results when applied to 4-alkyl- and 5,5-dialkyl-Δ2-pyrazolines and makes it possible to obtain the corresponding Δ1-pyrazolines in yields of 40–70%. 4-Ethyl-, 5-methyl-5-ethyl-, and 5,5-diethyl-Δ1-pyrazolines are described for the first time.

Keywords

Organic Chemistry Pyrazolines 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Consultants Bureau, a division of Plenum Publishing Corporation 1974

Authors and Affiliations

  • B. V. Ioffe
    • 1
  • N. B. Burmanova
    • 1
  1. 1.A. A. Zhdanov Leningrad State UniversityUSSR

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