2-Phthalimidoacetaldehyde Diethyl Acetal → 2-(7-Bromoquinolin-3-yl)isoindoline-1,3-dione

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Reaction Steps

A mixture of 2-(2,2-diethoxyethyl)isoindoline-1,3-dione (3.16 g, 12.00 mmol), 2-amino-4-bromobenzaldehyde (2 g, 10.00 mmol) and p-toluenesulfonic acid monohydrate (1.902 g, 10.00 mmol) in toluene (60 mL) was heated under reflux using Dean-Stark apparatus overnight. A very dark/black solid precipitated overnight and was collected, washed with toluene and hexanes, then dissolved in chloroform fortified with DMF. The mixture was washed with aq. NaHCO3 solution (×2), ensuring any precipitate was dissolved in additional chloroform during separation. The organic layer was dried (sodium sulfate) and evaporated onto silica gel. Purification by flash chromatography (0-2% methanol in dichloromethane) afforded the title compound (1.6 g, 45%). 1H NMR (400 MHz, DMSO-d6) δ ppm 9.05 (d, 1 H), 8.57 (d, J=2.3 Hz, 1 H), 8.35 (d, J=1.8 Hz, 1 H), 8.11 (d, J=8.6 Hz, 1 H), 8.09-8.02 (m, 2 H), 8.02-7.93 (m, 2 H), 7.87 (dd, J=1.9, 8.7 Hz, 1 H).

Provenance & Evidence