Cesium carbonate → 3-Bromo-5-(1-oxo-3,4,6,7,8,9-hexahydropyrazino[1,2-a]indol-2(1H)-yl)isonicotinaldehyde

Participants

Reaction Conditions

Reaction Steps

A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 101e (300 mg, 1.57 mmol), 3,5-dibromoisonicotinaldehyde (2) (517 mg, 1.96 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (XantPhos, 120 mg, 0.2 mmol), tris(dibenzylideneacetone)dipalladium(0) (180 mg, 0.2 mmol), Cs2CO3 (650 mg, 2 mmol), and 1,4-dioxane (8 mL). After three cycles of vacuum/argon flush, the mixture was heated at 100° C. for 6 h. It was then cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by flash column chromatography eluting with DCM/MeOH (from 40:1 to 20:1) to afford 101f as a pale yellow solid (350 mg, 40%). MS: [M+H]+ 374.

Provenance & Evidence