Trifluoroacetic acid → HCID 18369481, compound

Participants

Reaction Steps

To a solution of trifluoroacetic acid (558 mg) and triethylsilane (1.14 g) in dry dichloromethane (2.0 ml) were added ethyl 2-methylpyrazolo[1,5-a]pyridine-5-carboxylate (200 mg) and 2,4-dichlorobenzaldehyde (189 mg), and the mixture was stirred at room temperature for 3 days. To the reaction mixture was added 2,4-dichlorobenzaldehyde (189 mg) and the mixture was stirred at room temperature for one day. This step was repeated three times. The reaction mixture was diluted with dichloromethane and washed with a saturated aqueous sodium hydrogencarbonate solution. The aqueous layer was extracted with dichloromethane. The organic layers were combined, dried over magnesium sulfate, and concentrated to dryness under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=9:1) and washed with isopropyl ether to give the objective compound (233 mg) as a white powder.

Provenance & Evidence