1: PBr3, pyridine / diethyl ether 2: 1.) EtMgBr, 2.) CuI / 1.) THF, 40 deg C, 30 min, 2.) THF, a) 50 deg C, 3 h, b) RT, overnight 3: H2, quinoline / Pd/BaSO4 / ethyl acetate 4: lithium t-butyl thiolate / dimethylformamide View Scheme