PPA 1.) 95-100 deg C; 2.) 105-115 deg C, 2 h; 3.) rt, 8 h;

1: aqueous sulfuric acid 2: selenium / 310 - 330 °C View Scheme

1: 95 percent / polyphosphoric acid / 1.) 95-100 deg C; 2.) 105-115 deg C, 2 h; 3.) rt, 8 h 2: 1.) NaH / 1.) benzene, 62-64 deg C, 2 h; 2.) benzene, 70 deg C, 3 h 3: 1.) NaBH4 / 1.) methanol, 0 deg C, 30-45 min; 2.) methanol, r.t., 3-4 h 4: 79 percent / p-toluenesulfonic acid monohydrate, hydroquinone / benzene / Heating View Scheme

1: 82.2 percent / acetyl chloride 2: benzene; diethyl ether / reflux, 3 h -> room temperature 3: PPA View Scheme