VARIOUS APPROACHES TO 4-(PYRROLIDIN-2-YL)PYRAZOLES

Authors

  • Tetiana I. Shvydenko Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660
  • Viacheslav A. Lysenko Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660
  • Sergiy L. Filimonchuk Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660
  • Svitlana V. Shishkina Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660. State Scientific Institution ''Institute for Single Crystals'', National Academy of Sciences of Ukraine, 60 Nauky Ave., Kharkiv 61072
  • Kostiantyn G. Nazarenko Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660
  • Aleksandr N. Kostyuk Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660

Keywords:

lactim ethers, pyrazol-5-ones, 4-(pyrrolidin-2-yl)pyrazoles, reduction, reductive dechlorination

Abstract

A reliable systematic approach to a series of substituted 4-(pyrrolidin-2-ylidene)pyrazol-5-ones was developed. The compounds were synthesized through the reaction of pyrazol-5-ones with cyclic lactim ethers or lactam acetals. Subsequent treatment with phosphorus oxychloride yielded 5-chloro-4-(3,4-dihydro-2H-pyrrol-5-yl)-1H-pyrazoles, which possess both an active chlorine atom and an imine group. These intermediates underwent stepwise reduction – either targeting the imine group followed by reductive dechlorination, or vice versa – a direct reduction to produce 4-pyrrolidin-2-yl)pyrazoles. These products serve as valuable building blocks in medicinal chemistry, offering potential for further functionalization and application in drug design. 

Author Biography

Aleksandr N. Kostyuk, Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Akademika Kukharya St., Kyiv-94 02660

зав. отделом химии фосфорорганических соединений

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Published

2026-02-24

Issue

Vol. 61 No. 9/10 (2025): Modern catalytic approaches for the assembly and functionalization of heterocyclic compounds

Section

Original Papers