in ethyl acetate 1.) 3 h, reflux, 2.) 12 h, room temp.;

1: 60 percent / sodium acetate / acetic acid / 0.5 h 2: 42 percent / 10percent Na2S2O4 / ethanol / 1 h / Ambient temperature 3: 76 percent / ethyl acetate / 1.) 3 h, reflux, 2.) 12 h, room temp. View Scheme

1: 42 percent / 10percent Na2S2O4 / ethanol / 1 h / Ambient temperature 2: 76 percent / ethyl acetate / 1.) 3 h, reflux, 2.) 12 h, room temp. View Scheme

1: 79 percent / Na2S2O4 / H2O / 1 h / Ambient temperature 2: 76 percent / ethyl acetate / 1.) 3 h, reflux, 2.) 12 h, room temp. View Scheme