Highly Selective Synthesis of Chlorophenols under Microwave Irradiation
Table 2
Oxychlorination of phenol.
Entry
Acid
Catalyst
Dioxygen flow rate (mL/min)
Conversion (%)
Selectivity (%)
1
—
CuCl2 (0.1 eq.)
O2 (22 mL/min)
—
—
2
—
CuCl2 (2 eq.)
O2 (22 mL/min)
—
—
3
HCl (6 mol/L)
CuCl2 (0.1 eq.)
—
30.2
96.3
4
HCl (6 mol/L)
—
O2 (22 mL/min)
—
—
5
HCl (6 mol/L)
CuCl2 (0.1 eq.)
O2 (22 mL/min)
93.4
96.6
6
HCl (6 mol/L)
CuCl2 (2 eq.)
O2 (22 mL/min)
94.1
96.9
7
HCl (2 mol/L)
CuCl2 (0.1 eq.)
O2 (22 mL/min)
77.7
95.7
8
HCl (6 mol/L)
LiCl (2 eq.)
O2 (22 mL/min)
3.1
93.1
9
H2SO4 (6 mol/L)
CuCl2 (2 eq.)
O2 (22 mL/min)
10.3
96.0
Conditions: microwave irradiation; solvent, H2O for 1-2, aqueous hydrochloric acid solution for 3–8, aqueous sulfuric acid solution for 9; reaction time (60min); reaction temperature (50°C). Conversion and selectivity were determined by GC.
