Solvent‐free condensation of aromatic aldehydes and 2,3‐dimethyl‐1‐phenyl‐3‐pyrazolin‐5‐one by
<i>p</i>
‐toruenesulfonic acid
作者:Hideko Koshima、Mitsuo Hamada
DOI:10.1002/jhet.5570390538
日期:2002.9
Solvent-free condensation easily occurred by mixing aromatic aldehydes and 2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (antipyrine) in the presence of p-toluenesulfonic acid as a solid acid catalyst at room temperature to give the corresponding disubstituted products as sole products in high yields.