carbon tetrabromide; triphenylphosphine in tetrahydrofuran T=20°C; 5 h;

1: 99.2 percent / NaBH4 / methanol / 1 h / 20 °C 2: 35.7 percent / CBr4; PPh3 / tetrahydrofuran / 5 h / 20 °C View Scheme

1.1: AlCl3 / CH2Cl2 / 0.5 h / 0 °C 1.2: 99.2 percent / CH2Cl2 / 1 h / 0 °C 2.1: 99.2 percent / NaBH4 / methanol / 1 h / 20 °C 3.1: 35.7 percent / CBr4; PPh3 / tetrahydrofuran / 5 h / 20 °C View Scheme