1: With oxalyl dichloride; N,N-dimethyl-formamide in dichloromethane T=20°C; 1 h; 2: With sodium azide; water in acetone T=0 - 70°C;

1: 2-chloro-4-fluoro-1-methoxy-benzene With n-butyllithium in tetrahydrofuran T=-70°C; 1.5 h; 2: carbon dioxide in tetrahydrofuran T=-70°C; 0.166667 h; 3: With hydrogenchloride; sodium hydroxide more than 3 stages;

1: 2-chloro-4-fluoro-1-methoxy-benzene With n-butyllithium in tetrahydrofuran T=-65°C; 1.5 h; Inert atmosphere; 2: carbon dioxide in tetrahydrofuran T=-60 - -20°C; 0.666667 h;