2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-75°C; 2 h;

1: 2,6-difluoro-1-bromobenzene With 2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-75°C; 2 h; 2: carbon dioxide in tetrahydrofuran; hexane

carbon dioxide; diisopropylamine in tetrahydrofuran; cyclohexane

1: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 2: 96 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

1: 94 percent / butyllithium; bromine / hexane; tetrahydrofuran / 0.75 h / -75 °C 2: diisopropylamine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C 3: 96 percent / 2,2,6,6-tetramethylpiperidine; butyllithium / hexane; tetrahydrofuran / 2 h / -75 °C View Scheme

n-butyllithium 1) hexane, Et2O, 2 min, -78 deg C. 2) ether; Yield given. Multistep reaction. Yields of byproduct given;

sodium hydroxide; zinc Heating;