ammonium acetate in N,N-dimethyl-formamide 2 h; Heating;

in N-methyl-acetamide

1: 95 percent / ammonium acetate / toluene / 5 h / Heating 2: 43 percent / dimethylformamide / 1) RT, 3.5 h, 2) reflux, 24 h 3: 70 percent / Brederck's reagent / dioxane / 2.5 h / Heating 4: 98 percent / ammonium acetate / dimethylformamide / 2 h / Heating View Scheme

1: 43 percent / dimethylformamide / 1) RT, 3.5 h, 2) reflux, 24 h 2: 70 percent / Brederck's reagent / dioxane / 2.5 h / Heating 3: 98 percent / ammonium acetate / dimethylformamide / 2 h / Heating View Scheme

1: 70 percent / Brederck's reagent / dioxane / 2.5 h / Heating 2: 98 percent / ammonium acetate / dimethylformamide / 2 h / Heating View Scheme