A SIMPLE SYNTHESIS OF NOVEL EXTRACTION REAGENTS. 4-ACYL-5-PYRAZOLONE-SUBSTITUTED CROWN ETHERS

A synthesis of novel 4-acylpyrazol-5-one-substituted crown ethers metal-chelating reagents is described. 4-Acylpyrazol-5-one-substituted dibenzo-16-crown-5 1a, 4-acylpyrazol-5-one-substituted dibenzo-19-crown-6 1b, and bis(4-acylpyrazol-5-one)-substituted diaza-18-crown-6 1c were designed and synthesized by simple coupling reactions between α-chloro 4-acylpyrazol-5-one 3 and the corresponding crown ethers 2a–c. Compound 1a was found to be an effective and metal ion-selective extraction reagent.