2-Iodoxybenzoic acid → 5-(2-diethylamino-ethyl)-3-trifluoromethyl-4-oxo-4,5,6,7-tetrahydro-1H-pyrrolo[3,2-c]pyridine-2-carbaldehyde

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Reaction Steps

A stirred solution of 5-(2-diethylamino-ethyl)-2-hydroxymethyl-3-trifloromethyl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one (1.208 g, 3.63 mmol) and 4-methylbenzenesulfonic acid monohydrate (690 mg, 3.63 mmol) in 8 ml of N,N-dimethyl sulfoxide was added dropwise with 2-iodoxybenzoic acid (1.63 g, 5.8 mmol) in 8 ml of N,N-dimethyl sulfoxide. Upon the completion of the addition, the mixture was stirred at room temperature for 2.5 hours. The reaction mixture was added with ice to quench the reaction and filtered. The filtrate was added with saturated sodium carbonate to adjust pH9˜10, extracted with dichloromethane (50 ml×5). The combined organic phase was washed with saturated sodium carbonate (10 ml), saturated sodium chloride (10 ml), dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by the silica gel column chromatography with dichloromethane: n-hexane: methanol:ammonia (200:20:10:0.5) as eluents to give 5-(2-diethylamino-ethyl)-3-trifluoromethyl-4-oxo-4,5,6,7-tetrahydro-1H-pyrrolo[3,2-c]pyridine-2-carbaldehyde (407 mg, 28%) as a yellow solid.

Provenance & Evidence