Synthesis of 5-amino-1,5-diarylpenta-2,4-dien-1-ones

Nucleophilic addition of morpholine and piperidine to 1,5-diarylpent-2-en-4-yn-1-ones involves the triple bond in the latter, regardless of the substituents in the aryl rings, to produce the corresponding (E,E)-5-(morpholin-4-yl or piperidin-1-yl)-1,5-diarylpenta-2,4-dien-1-ones in up to 93% yield. According to the X-ray diffraction data, the synthesized compounds in crystal have s-cis and s-trans conformations of the enone and dienone fragments, respectively.