1: 91 percent / p-toluenesulfonic acid / benzene / 3 h / Heating 2: 1.) n-BuLi / 1.) ether, hexane, RT, 15 min, 2.) 22 deg C, 1 h 3: 72 percent / H2, potassium carbonate / Lindlar catalyst / toluene / 3 h / 20 °C / 760 Torr 4: PBr3 / diethyl ether / 0.08 h / Ambient temperature 5: 69 percent / benzene / Heating 6: 78 percent / NaOCH3 / CH2Cl2; methanol / 1 h / -10 °C View Scheme

toluene-4-sulfonic acid in benzene 9 h; Heating;

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