Synthesis and reactivity of Mannich bases. Part 15: Synthesis of 3-(2-(1-pyrazolyl)ethyl)-1,2-benzisoxazoles

Four new Mannich bases derived from ortho-hydroxyacetophenones and containing pyrazoles as amine moieties have been subjected to oximation in alkaline medium. The selective acetylation to the oximino hydroxyl of the resulting oximes led to the corresponding oxime-acetates. These have been transformed via a ring closure reaction in refluxing benzene and in the presence of anhydrous K2CO3 into 3-(2-(1-pyrazolyl)ethyl)-1,2-benzisoxazoles, valuable as potential pharmacologically relevant compounds.