Synthesis and screening for analgesic activity of certain 1,3-diketone derivatives

ABSTRACT

Claisen condensation of p-bromoacetophenone and p-hydroxyacetophenone with ethyl acetate afforded 1-aryl-1,3-butanediones [1]. Cyclization of 1 with hydrazine hydrate gave the pyrazole derivatives [3]. Acylation of 3 with acid chlorides produced the acyl derivatives [4]. The reaction of 1-[4-hydroxyphenyl] 1,3-butanedione with certain aromatic amines yielded 1-aryl-3-substituted amino-2-buten-1-one derivatives [5]. Furthermore, refluxing 1 with aromatic aldehydes afforded the styrene derivatives [6] or [7] according to the reaction conditions. Pharmacological screening has revealed that some of these derivatives showed slight analgesic activity