potassium carbonate in N,N-dimethyl-formamide T=20°C; 20 h;

potassium carbonate in dimethyl sulfoxide 22 h; Ambient temperature;

1: With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 1.16667 h; Inert atmosphere; 2: With 1,2-dibromo-1,1,2,2-tetrachloroethane in tetrahydrofuran T=-78°C; 2.16667 h; Inert atmosphere;

in methanol 18 h; Ambient temperature;