RING-CHAIN TAUTOMERISM OF 3-UNSUBSTITUTED TRIFLUOROMETHYL-CONTAINING <i>N</i>-ACYL-5-HYDROXY-2-PYRAZOLINES
DOI:
https://doi.org/10.1007/1769Keywords:
enamino ketones, 4-ethoxy-1, 1, 1-trifluorobut-3-en-2-one, hydrazides of aromatic acids, hydrazides of pyridinecarboxylic acids, 5-hydroxy-2-pyrazolines, ring-chain tautomerismAbstract
Reaction of the hydrazides of aromatic and pyridine-3(4)-carboxylic acids with 4‑ethoxy-1,1,1-tri-fluorobut-3-en-2-one leads to the formation of derivatives having a 5-hydroxy-2-pyrazoline structure. In solution in DMSO-d6 they are capable of exhibiting ring-chain equilibrium involving the 5-hydroxy-2-pyrazoline and enehydrazine tautomers. The latter form is represented by a mixture of Z- and E‑isomers with a significant preponderance of the latter. The product from the reaction of 4‑aminobenzohydrazide with 4-ethoxy-1,1,1-trifluorobut-3-en-2-one in a ratio of 1:2 has a structure containing 5-hydroxy-2-pyrazoline and enamine fragments.
How to Cite
Pakal'nis, V. V.; Zerov, A. V.; Yakimovich, S. I.; Alekseev, V. V. Chem. Heterocycl. Compd. 2014, 50, 1107. [Khim. Geterotsikl. Soedin. 2014, 1201.]
For this article in the English edition see DOI 10.1007/s10593-014-1570-8
