1.1: 2,4,6-trichlorobenzoyl chloride; triethylamine / toluene / 5 h / 20 °C 1.2: 84 percent / 4-(dimethylamino)pyridine / toluene / 0.5 h / 20 °C 2.1: pyridinium poly(hydrogen fluoride) / tetrahydrofuran / 12 h / 20 °C 3.1: 8.0 mg / mercury(II) perchlorate trihydrate; calcium carbonate / acetonitrile; H2O / 0.05 h / 20 °C View Scheme