SOLID-PHASE SYNTHESIS OF POLYMER-BOUND β-KETOESTERS AND THEIR APPLICATION IN THE SYNTHESIS OF STRUCTURALLY DIVERSE PYRAZOLONES

An efficient solid-phase synthesis of different polymer-bound β-ketoesters 7 is described using readily available acid chlorides 1 and haloalkanes 6 as building blocks. The corresponding pyrazolones 9 and 10 were obtained by mild acid catalyzed reaction with phenylhydrazine or by treatment with hydrazine under cyclisation and cleavage from the resin in high purity and good yield. © 1997 Elsevier Science Ltd.