What Is Chalcone Scaffolds?

Chalcone scaffolds had attracted many researchers to investigate their synthetic routes, potential biological activities and their roles as intermediates for naturally occurring flavanoid skeletons. This study focused on the synthesis of chalcones bearing O-, C-prenyl and chromane as substituents. The target compounds were purified by chromatographic methods and structures of all compounds were determined by using IR, NMR and MS spectroscopies. The prenylated precursors were synthesized initially from 2,4-dihydroxyacetophenone (65) and 2,4,6-trihydroxyacetophenone (93). Prenylation of 2,4-dihydroxyacetophenone using prenyl bromide had successfully gave 2-hydroxy-4-O-prenylacetophenone (101). A reaction of 2,4,6-trihydroxyacetophenone with prenyl bromide in the presence of base resulted in a mixture and chromatographic purification gave 2,4,6-trihydroxy-3-C-prenylacetophenone (132) and 2,4-dihydroxy-5,6-chromanacetophenone (133). …show more content…
C-prenylated acetophenone (132) was then converted to 2-hydroxy-3-C-prenyl-4,6-dimethoxyacetophenone (137) using methyl iodide in the presence of potassium carbonate. Claisen-Schmidt condensation of O- and C-prenylated acetophenone with individual benzaldehyde 4-(N,N-dimethyl)aminobenzaldehyde (61), 2-methoxybenzaldehyde (126), 4-isopropylbenzaldehyde (127), 3,4-dimethoxybenzaldehyde (128) and 4-chlorobenzaldehyde (129) resulted in the formation of two series of chalcones with five chalcones for each