H. Morita, K. Harada, Y. Okamoto
May 1, 1999
Citations
0
Influential Citations
11
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
3-Chloro- and 3-bromo-4-methoxycoumarins 1a,b were readily transformed into 4-halo-5-(2-hydroxyphenyl)-3-oxo-2,3-dihydropyrazoles 2a,b with hydrazines. In the reaction of 1a,b with excess hydrazine and phenylhydrazine in boiling ethanol, unexpected 4-hydrazono-3-(2-hydroxyphenyl)-2-pyrazolin-5-ones 3, 5 were obtained. The structure of 3 was determined by X-ray diffraction analysis.