N,N,N',N,-tetramethylethylenediamine; 1,2,2-trichloro-1,1,2-trichloro-ethane; sec.-butyllithium in tetrahydrofuran 1.) -90 deg C, 30 min, 2.) -78 deg C;

1: 3,4-difluoro-benzoic acid With N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78°C; 1 h; 2: 1,2,2-trichloro-1,1,2-trichloro-ethane in tetrahydrofuran; cyclohexane T=-78 - 20°C; 1 h; 3: With water in tetrahydrofuran; cyclohexane

ammonia; benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride in water; N,N-dimethyl-formamide T=20°C; 40 h;