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NEW ONE-POT SYNTHESIS OF 4-HYDROXYIMINO-5-POLYFLUOROALKYLPYRAZOL-3-ONES, THEIR STRUCTURE AND BIOLOGICAL ACTIVITY
Abstract
We propose different methods for the synthesis of 4-hydroxyimino-5-polyfluoroalkylpyrazol-3-ones. The simplest and most convenient
procedure relies on sequential one-pot treatment of polyfluoroalkyl-3-oxoesters with hydrazine and sodium nitrite in acetic acid. It was established that 4-hydroxyimino-5-polyfluoroalkylpyrazol-3-ones exist in solid state and in solutions as mixtures of Z,Е-isomers of the hydroxyimine tautomer. The synthesized compounds were characterized with respect to in vivo analgesic activity and acute toxicity.
procedure relies on sequential one-pot treatment of polyfluoroalkyl-3-oxoesters with hydrazine and sodium nitrite in acetic acid. It was established that 4-hydroxyimino-5-polyfluoroalkylpyrazol-3-ones exist in solid state and in solutions as mixtures of Z,Е-isomers of the hydroxyimine tautomer. The synthesized compounds were characterized with respect to in vivo analgesic activity and acute toxicity.
Keywords
2-hydroxyimino-3-polyfluoroalkylpyrazol-5-ones, analgesic activity, nitrosation, tautomerism.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv