The title compound, (E)-5-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)benzo[d]oxazol-2(3H)-one, was synthesized by the acid- and base-catalyzed aldol condensation of 2-oxo-2,3-dihydrobenzo[d]oxazole-5-carbaldehyde and 3,4,5-trimethoxyacetophenone. The structure of the target compound was confirmed using ¹H NMR, ¹³C NMR, HRMS, and elemental analysis.

The title compound, (E)-3-methyl-6-(3-oxo-3-(thiophen-2-yl)-1-propenyl)-2(3H)-benzothiazolone, was synthesized by Claisen-Schmidt condensation of 3-methyl-2(3H)-benzothiazolone-6-carbaldehyde with 2-acetylthiophene in 94% yield. The structure of the target compound was confirmed using ¹H-NMR, ¹³C-NMR, IR, MS, and elemental analysis.

A series of chlorinated chalcone derivatives containing oxazole and thiazole rings were synthesized via Claisen–Schmidt condensation of 6-acetyl-2(3H)-benzoxa(thia)zolone with substituted chlorobenzaldehydes. The synthesized compounds were evaluated for their antimicrobial activity against selected bacterial and fungal strains. Several compounds demonstrated moderate antimicrobial activity against the tested microorganisms.

The title compound, 6-[1-acetyl-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl]-2(3H)-benzoxazolone, was synthesized by condensation of 6-[3-(4-methoxyphenyl)-2-propenoyl]-2(3H)-benzoxazolone (1) and hydrazine hydrate in acetic acid in 84% yield. The structure of the target compound was confirmed using ¹H-NMR, ¹³C-NMR, IR, MS, and elemental analysis.

The title compound, (E)-3-methyl-6-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)-2(3H)-benzothiazolone, was synthesized by both an acid- and base-catalyzed aldol condensation of 3-methyl-6-acetyl-2(3H)-benzothiazolone and 3,4,5-trimethoxyacetophenone. The structure of the target compound was confirmed using ¹H-NMR, ¹³C-NMR, IR, MS, and elemental analysis.

A new hybrid molecule containing a triazole and a benzoxazolone ring was synthesized. The structure of 6-[(4-chlorophenyl)(1H-1,2,4-triazol-1-yl) methyl]-3-methyl-2(3H)-benzoxazolone was confirmed by IR, ¹H-, ¹³C-NMR, MS and elemental analysis.