Acylation of 1-arylpyrazolidin-3-ones

Article abstract of DOI:10.1007/BF02290844

Acylation of 1-arylpyrazolidin-3-ones using aromatic acid anhydrides and chlorides in the presence of base occurs principally at the oxygen atom to give 1-aryl-3-acyloxy-2-pyrazolines, subsequent heating or microwave irradiation of which leads to the corresponding N-acylpyrazolidin-3-ones. The action of aliphatic acid anhydrides and chlorides on 1-arylpyrazolidin-3-ones gives predominantly the N-acylpyrazolidin-3-ones.