potassium carbonate in N,N-dimethyl-formamide T=80 - 100°C; 4 h;

1: With water; bis-[(trifluoroacetoxy)iodo]benzene in acetonitrile T=65°C; 30 h; 2: With hydrogenchloride in water; acetonitrile pH=1; 3: With sodium carbonate in water pH=8 - 9;

triethylamine in dichloromethane T=20°C; 2 h;