sec.-butyllithium 1) - 10 deg C, hexane, THF, 2) -5 deg C to room temperature, 3.5 h; Multistep reaction. Title compound not separated from byproducts;

1: 75 percent / Mg / tetrahydrofuran / 18 h / Heating 2: 67 percent / 1) sec-butyllithium / 1) - 10 deg C, hexane, THF, 2) -5 deg C to room temperature, 3.5 h View Scheme