1: ethyl 8-methoxy-5,6-dihydro-5-methyl-6-oxo-4H-imidazolt;1,5-agt;lt;1,4gt;benzodiazepine-3-carboxylate With boron tribromide in dichloromethane T=-70°C; 2: ethanol in dichloromethane T=20°C; Cooling;

1.1: sodium hydride / N,N-dimethyl-formamide; tetrahydrofuran; mineral oil / Inert atmosphere 1.2: Cooling; Inert atmosphere 1.3: 18 h / 20 °C / Inert atmosphere 2.1: boron tribromide / dichloromethane / -70 °C 2.2: 20 °C / Cooling View Scheme

1.1: dimethyl sulfoxide / 2 h / 157 °C 2.1: sodium hydride / N,N-dimethyl-formamide; tetrahydrofuran; mineral oil / Inert atmosphere 2.2: Cooling; Inert atmosphere 2.3: 18 h / 20 °C / Inert atmosphere 3.1: boron tribromide / dichloromethane / -70 °C 3.2: 20 °C / Cooling View Scheme

1.1: 1,4-dioxane / 1 h / Cooling; Reflux 2.1: dimethyl sulfoxide / 2 h / 157 °C 3.1: sodium hydride / N,N-dimethyl-formamide; tetrahydrofuran; mineral oil / Inert atmosphere 3.2: Cooling; Inert atmosphere 3.3: 18 h / 20 °C / Inert atmosphere 4.1: boron tribromide / dichloromethane / -70 °C 4.2: 20 °C / Cooling View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide; tetrahydrofuran; mineral oil / Inert atmosphere 1.2: Cooling; Inert atmosphere 1.3: 18 h / 20 °C / Inert atmosphere 2.1: boron tribromide / dichloromethane / -70 °C 2.2: 20 °C / Cooling View Scheme