1: 8-Bromo-3-methyl-3,7-dihydropurine-2,6-dione With N-ethyl-N,N-diisopropylamine in N,N-dimethyl-formamide T=-25 - 70°C; Inert atmosphere; 2: 3',4'-dihydroxy-2-chloroacetophenone in N,N-dimethyl-formamide T=70°C; 5 h; Inert atmosphere;

in N,N-dimethyl-formamide 1.5 h; Heating;