carbon disulfide; n-butyllithium; benzeneseleninic acid; 1,1,1,3,3,3-hexamethyl-disilazane 1.) THF, hexane, -20 deg C, 30 min, 2.) THF, rt, 3.) THF, rt, 5 h; Yield given. Multistep reaction;

1: 1.) hexamethyldisilazane, 1.6 M n-BuLi, 2.) CS2, 3.) PhSeO2H / 1.) THF, hexane, -20 deg C, 30 min, 2.) THF, rt, 3.) THF, rt, 5 h 2: 95 percent / DCC, 4-dimethylaminopyridine / CH2Cl2 View Scheme

1: 1.) hexamethyldisilazane, 1.6 M n-BuLi, 2.) CS2, 3.) PhSeO2H / 1.) THF, hexane, -20 deg C, 30 min, 2.) THF, rt, 3.) THF, rt, 5 h 2: oxalyl chloride, DMF / benzene / Ambient temperature View Scheme

1: 1.) hexamethyldisilazane, 1.6 M n-BuLi, 2.) CS2, 3.) PhSeO2H / 1.) THF, hexane, -20 deg C, 30 min, 2.) THF, rt, 3.) THF, rt, 5 h 2: oxalyl chloride, DMF / benzene / Ambient temperature 3: pyridine / benzene / 2 h View Scheme