1: 58 percent / 1N-HCl / 1.5 h / Heating 2: 72 percent / triethylamine / dioxane / 0.33 h / Heating 3: 70 percent / 1,3-dibromo-5,5-dimethylhydantoin, benzoyl peroxide / CCl4 / 0.33 h / Heating; Irradiation 4: K2CO3 / dimethylformamide / 4 h / 75 °C 5: NaOCH3 / methanol / 1.5 h / Heating View Scheme

1: 51 percent / SnCl2*2H2O, conc. HCl / 0.25 h / below 40 deg C 2: 58 percent / 1N-HCl / 1.5 h / Heating 3: 72 percent / triethylamine / dioxane / 0.33 h / Heating 4: 70 percent / 1,3-dibromo-5,5-dimethylhydantoin, benzoyl peroxide / CCl4 / 0.33 h / Heating; Irradiation 5: K2CO3 / dimethylformamide / 4 h / 75 °C 6: NaOCH3 / methanol / 1.5 h / Heating View Scheme

1: K2CO3 / dimethylformamide / 4 h / 75 °C 2: NaOCH3 / methanol / 1.5 h / Heating View Scheme

1: various solvent(s) / 5 h / 160 °C 2: 51 percent / SnCl2*2H2O, conc. HCl / 0.25 h / below 40 deg C 3: 58 percent / 1N-HCl / 1.5 h / Heating 4: 72 percent / triethylamine / dioxane / 0.33 h / Heating 5: 70 percent / 1,3-dibromo-5,5-dimethylhydantoin, benzoyl peroxide / CCl4 / 0.33 h / Heating; Irradiation 6: K2CO3 / dimethylformamide / 4 h / 75 °C 7: NaOCH3 / methanol / 1.5 h / Heating View Scheme

1: 72 percent / triethylamine / dioxane / 0.33 h / Heating 2: 70 percent / 1,3-dibromo-5,5-dimethylhydantoin, benzoyl peroxide / CCl4 / 0.33 h / Heating; Irradiation 3: K2CO3 / dimethylformamide / 4 h / 75 °C 4: NaOCH3 / methanol / 1.5 h / Heating View Scheme

1: 70 percent / 1,3-dibromo-5,5-dimethylhydantoin, benzoyl peroxide / CCl4 / 0.33 h / Heating; Irradiation 2: K2CO3 / dimethylformamide / 4 h / 75 °C 3: NaOCH3 / methanol / 1.5 h / Heating View Scheme