Cesium carbonate → 4-(2-Methoxy-6-nitrophenyl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of BOC-homopiperazine (1.0 g, 5 mmol, 1 equiv), 2-bromo-1-methoxy-3-nitrobenzene (1.16 g, 1 equiv), cesium carbonate (1.7 g, 1 equiv) in 10 mL of DMF was heated at 60° C. over 72 hrs. After cooling down to room temperature, ethyl acetate (100 mL) and water (50 mL) were added. The organic layer was subjected to flash chromatography (5 to 40% ethyl acetate in hexane) to give 4-(2-methoxy-6-nitrophenyl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester (0.50 g, 25%), which was then treated with 50 mL of 4N HCl in dioxane at 60° C. for 2 hrs. The mixture was then evaporated to dryness and used in the next step directly. MS (ES) m/z 252.1 (M+H+).

Provenance & Evidence