4-Oxo-1H-and-2H-[1]benzopyrano[4,3-c]pyrazoles. Preparation from 4-hydroxycoumarin or 3-chromonecarboxylic acid derivatives.
作者:Bernard Chantegrel、Abdel-Ilah Nodi、Suzanne Gelin
DOI:10.1016/s0040-4039(00)81413-6
日期:——
The conversion of 3-acyl-4-hydroxycoumarins to either 4-oxo-1-phenyl-1H-[1]benzopyrano[4,3-c]pyrazoles or 4-oxo-2-phenyl-2H-[1]benzopyrano[4,3-c]pyrazoles is described. The product obtained from the reaction of phenylhydrazine with 3-chromonecarboxylic acid has been established not to be such 2-phenyl[1]benzopyrano[4,3-c]pyrazol-3-2H-one as previously reported but to be 4-oxo-1-phenyl-1H[1]benzopyrano[4
3-酰基-4-羟基香豆素转化为4-氧代-1-苯基-1H- [1]苯并吡喃并[4,3-c]吡唑或4-氧代-2-苯基-2H- [1]苯并吡喃[描述了4,3-c]吡唑。已经确定由苯肼与3-色酮羧酸反应获得的产物不是先前报道的2-苯基[1]苯并吡喃并[4,3-c]吡唑-3-2H-酮,而是4-氧代。 -1-苯基-1H [1]苯并吡喃并[4,3-c]吡唑。我们的结果表明,以前描述为从4-氯-3-甲酰基-香豆素中收率的方法是不可行的。