sulfur in toluene 32 h; Heating;

1.1: tetrahydrofuran / 1 h / 0 °C 2.1: CuBr*SMe2; dimethyl sulfide / tetrahydrofuran / -20 °C 2.2: 71 percent / tetrahydrofuran / 3 h / -78 °C 3.1: 79 percent Chromat. / sulfur / toluene / 32 h / Heating View Scheme

sulfuric acid; iron(II) sulfate in water 3.5 h;

in toluene 7 h; Heating;

in toluene Heatingvar conc., var. solv.; Product distributionMechanism;