New Synthesis of 3-Bromoflavones via Bromination of 1-(2-Hydroxyphenyl)-3-arylpropane-1,3-dione by CuBr<sub>2</sub>, and Conversion into 3-Aminoflavones
A new synthesis of 3-bromoflavones from 1-(2-hydroxyphenyl)-3-arylpropane-1,3-dione using CuBr2 is described. The usefulness of 3-bromoflavone as a precursor of 3-aminoflavone is also described.
A new protocol for total synthesis of natural product frutinone A was accomplished in three steps by using inexpensive 2′-hydroxyacetophenone as starting material. The key intermediate 3-(2-chlorobenzoyl)-4-hydroxycoumarin was synthesized in one pot through Baker–Venkataraman rearrangement of 2-acetylphenyl 2-chlorobenzoate followed by introduction of methyl chloroformate under basic conditions. Then