| Autor: |
Cantos, Albert, March, Pedro de, Moreno-Mañas, Marcial, Pla, Anna, Sanchez-Ferrando, Francisco, Virgili, Albert |
| Zdroj: |
Bulletin of the Chemical Society of Japan; December 1987, Vol. 60 Issue: 12 p4425-4431, 7p |
| Abstrakt: |
Cyclization of dehydroacetic acid N-substituted hydrazones furnished 1-substituted 3,6-dimethylpyrano[4,3-c]pyrazol-4(1H)-ones, together with varying amounts of N,N′-disubstituted 5-hydroxy-3-methyl-4-(3-methyl-1H-pyrazol-5-yl)-1H-pyrazoles. The same pyranopyrazolones were obtained regioselectively without side reactions from N-alkylhydrazines and 4-chloro-3-(1-chlorovinyl)-6-methyl-2H-pyran-2-one, (“Dehydroacetchlorid”), while N-arylhydrazines gave the 2-aryl-3,6-dimethylpyrano[4,3-c]pyrazol-4(2H)-ones. NMR NOE methods, including long-range selective heteronuclear 13C{1H} NOE enhancement measurements, allowed unambiguous distinction between -4(1H)-ones and -4(2H)-ones. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
