1: methanol With sodium methylate; copper(I) bromide in N,N-dimethyl-formamide T=20°C; Wessely-Moser rearrangement; 1 h; 2: 8-bromo-5-hydroxy-7,4'-dimethoxyflavone; 6-bromo-5-hydroxy-7,4'-dimethoxyflavone in N,N-dimethyl-formamide T=120°C; 5 h;

1.1: sodium methylate; copper(I) bromide / N,N-dimethyl-formamide / 1 h / 20 °C 1.2: 5 h / 120 °C 2.1: hydrogen bromide; acetic acid / water View Scheme