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

Participants

Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 103a (800 mg, 3.5 mmol), 3,4,6,7,8,9-hexahydropyrazino[1,2-a]indol-1(2H)-one 101e (665 mg, 3.5 mmol), tris(dibenzylideneacetone)dipalladium(0) (320 mg, 0.35 mmol), XantPhos (400 mg, 0.7 mmol), Cs2CO3 (2.3 g, 7.0 mmol), and 1,4-dioxane (20 mL). After three cycles of vacuum/argon flush, the mixture was heated at 90° C. for 5 h. It was then cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by silica-gel column chromatography eluting with dichloromethane/methanol (80:1) to afford 103b as a yellow solid (1.2 g, 50%). MS: [M+H]+ 330.

Provenance & Evidence