94487-88-4Relevant articles and documents
5-Hydroxy-4,5-Dihydropyrazoles
Zelenin, Kirill N.,Alekseyev, Valery V.,Tygysheva, Alja R.,Yakimovitch, Stanislav I.
, p. 11251 - 11256 (1995)
The use of β-diketones with strong electron-withdrawing substituents in reaction with hydrazine and its monosubstituted derivatives leads to the stable intermediates of pyrazole synthesis - 5-hydroxy-4,5-dihydropyrazoles or their open chain isomers.
Synthesis of Pyrazole, 1,2,4,5-Tetrazine, and 1,2,4-Triazole Derivatives from Thiocarbonohydrazides and β-Dicarbonyl Compounds
Alekseev, V. V.,Zelenin, K. N.,Yakimovich, S. I.
, p. 868 - 873 (2007/10/03)
Reactions of acetylacetone, α-methylacetylacetone, and benzoyl- and 4-methoxybenzoylacetone with thiocarbonohydrazide yield corresponding pyrazoles with no substituent at N1.Reactions of 1-substituted thiocarbonohydrazides with acetylacetone, as well as of trifluoromethyl-substituted β-diketones and aroylacetones containing acceptor substituents with unsubstituted thiocarbonohydrazide, result in formation of corresponding 1-(N-aminothiocarbamoyl)-5-hydroxy-Δ5-pyrazolines which in some cases are converted into respective 1-(N-aminothiocarbamoyl)pyrazoles and further into 1-unsubstituted pyrazoles.Reaction of thiocarbonohydrazide with aroylacetaldehyde leads to 1,2,4,5-tetrazine-3-thiones.The product of reactions of 1,1,4-trimethylthiocarbonohydrazide with acetylacetone is a 1,2,4-triazole derivative.
