toluene-4-sulfonic acid in xylene Heating;

1: 59 percent / I2, KI, aq. NH4OH 2: 69 percent / (η3-C3H5PdCl)2, P(OEt)3, nBu4NF / tetrahydrofuran / 0.5 h / 60 °C 3: 71 percent / Tl(NO3)3 / Ambient temperature 4: 84 percent / p-TsOH / xylene / Heating View Scheme

1: 71 percent / Tl(NO3)3 / Ambient temperature 2: 84 percent / p-TsOH / xylene / Heating View Scheme

1: 69 percent / (η3-C3H5PdCl)2, P(OEt)3, nBu4NF / tetrahydrofuran / 0.5 h / 60 °C 2: 71 percent / Tl(NO3)3 / Ambient temperature 3: 84 percent / p-TsOH / xylene / Heating View Scheme