N-ethyl-N,N-diisopropylamine in N,N-dimethyl-formamide T=80°C; 1 h;

sodium hydrogensulfide; water

sodium hydroxide; thiourea 1.) 180-200 deg C, 2.5 h, 2.) H2O, reflux, 2.5 h; Yield given. Multistep reaction;

1: aq. HBr 2: (i) thiourea, EtOH, (ii) aq. NaOH, (iii) Na2S View Scheme

1: 1.) N,N'-dicyclohexylcarbodiimide, 2.) K2CO3 / 1.) AcOEt, RT, 40 min, 2.) water, DMF, RT, overnight 2: 63.2 percent / I2, Et3N / ethyl acetate / 1 h / -10 - 5 °C View Scheme

lithium aluminium tetrahydride in diethyl ether T=20°C; 48 h; Inert atmosphere;

1: 72 percent / iodine, sodium hydroxide, potasium iodide, sodium sulphide / methanol 2: SOCl2 / benzene / 4 h / Heating 3: CH2Cl2 / 2 h / Ambient temperature 4: 57 percent / pyridine, bromine / CH2Cl2 / from -78 deg C to room temp. 5: 92 percent / diethyl ether / 30 h / from -78 deg C to room temp. View Scheme

1: 72 percent / iodine, sodium hydroxide, potasium iodide, sodium sulphide / methanol 2: SOCl2 / benzene / 4 h / Heating 3: CH2Cl2 / 2 h / Ambient temperature 4: 57 percent / pyridine, bromine / CH2Cl2 / from -78 deg C to room temp. 5: 80 percent / sulphuryl chloride / CCl4 / Ambient temperature 6: 89 percent / diethyl ether / 30 h / from -78 deg C to room temp. View Scheme