1: With lithium diisopropyl amide in tetrahydrofuran T=-10°C; Metallation; 0.5 h; 2: With iodine in tetrahydrofuran T=-78 - 20°C; Iodination;

1.1: 90 percent / polyphosphoric acid / chlorobenzene / Heating 2.1: LDA / tetrahydrofuran / 0.5 h / -10 °C 2.2: 80 percent / I2 / tetrahydrofuran / -78 - 20 °C View Scheme

1.1: 81 percent / NaOEt / ethanol 2.1: 90 percent / polyphosphoric acid / chlorobenzene / Heating 3.1: LDA / tetrahydrofuran / 0.5 h / -10 °C 3.2: 80 percent / I2 / tetrahydrofuran / -78 - 20 °C View Scheme