1: 50 percent / Fe(3+)-clay / xylene / 12 h / Heating 2: 88 percent / K2CO3; H2O / ethyl acetate / 12 h / Heating 3: Et3N; DMAP / CH2Cl2 / 3 h / Heating View Scheme

1: 50 percent / Fe(3+)-clay / xylene / 12 h / Heating 2: 88 percent / K2CO3; H2O / ethyl acetate / 12 h / Heating View Scheme