Cesium carbonate → 3-Bromo-5-(1-oxo-6,7,8,9-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)isonicotinaldehyde

Participants

Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 1,4-dioxane (15 mL), 3,5-dibromoisonicotinaldehyde (604 mg, 2.28 mmol), 6,7,8,9-tetrahydropyrazino[1,2-a]indol-1(2H)-one (142 mg, 0.76 mmol) and cesium carbonate (485 mg, 1.5 mmol). CuI (143 mg, 0.76 mmol) and 4,7-dimethoxy-1,10-phenanthroline (127 mg, 0.52 mmol) were added, and the reaction mixture was heated at 100° C. for 5 h. After this time, the reaction was cooled to room temperature. It was then filtered and the filtrate was concentrated under reduced pressure. The residue was purified on flash column eluting with EtOAC/PE (1:2) to afford 126a (100 mg, 35%) as a yellow solid. MS: [M+H]+ 372.

Provenance & Evidence