1: 89 percent / TMSCl, NaI / acetonitrile / 6 h / 0 - 20 °C 2: 74 percent / Cs2CO3 / dimethylsulfoxide / 21 h / 47 - 50 °C View Scheme

1: 89 percent / TMSCl, NaI / acetonitrile / 6 h / 0 - 20 °C 2: 74 percent / Cs2CO3 / dimethylsulfoxide / 21 h / 47 - 50 °C 3: 93.4 percent / trifluoroacetic acid; toluene / 2 h / 110 °C 4: p-TSA*H2O / toluene; acetic acid / 18 h / 95 - 100 °C View Scheme

1: 89 percent / TMSCl, NaI / acetonitrile / 6 h / 0 - 20 °C 2: 74 percent / Cs2CO3 / dimethylsulfoxide / 21 h / 47 - 50 °C 3: 93.4 percent / trifluoroacetic acid; toluene / 2 h / 110 °C 4: p-TSA*H2O / toluene; acetic acid / 18 h / 95 - 100 °C 5: pyridine / 2 h / 20 - 25 °C View Scheme

1: 89 percent / TMSCl, NaI / acetonitrile / 6 h / 0 - 20 °C 2: 74 percent / Cs2CO3 / dimethylsulfoxide / 21 h / 47 - 50 °C 3: 93.4 percent / trifluoroacetic acid; toluene / 2 h / 110 °C 4: p-TSA*H2O / toluene; acetic acid / 18 h / 95 - 100 °C View Scheme

1: 89 percent / TMSCl, NaI / acetonitrile / 6 h / 0 - 20 °C 2: 74 percent / Cs2CO3 / dimethylsulfoxide / 21 h / 47 - 50 °C 3: 93.4 percent / trifluoroacetic acid; toluene / 2 h / 110 °C View Scheme