1H-Pyrrolo(2,3-b)pyridine → (2-Bromo-1,3-thiazol-5-yl)(1H-pyrrolo[2,3-b]pyridin-3-yl)methanone

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Reaction Steps

A suspension of 2-Bromo-thiazole-5-carboxylic acid (98, 0.5 g, 0.002 mol) in oxalyl chloride (3 mL) was stirred at room temperature until it turned into a clear solution. Solvent was removed and the residue was dried over vacuum. A light yellow solid was obtained and was dissolved in dichloromethane (10 mL) and slowly added to a solution of 1H-Pyrrolo[2,3-b]pyridine (1, 0.34 g, 0.0029 mol) in dichloromethane (30 mL) at −10° C. To the mixture was then added aluminum trichloride (2.6 g, 0.019 mol) in one portion with vigorous stirring. The reaction was held at −10° C. for 30 minutes, then allowed to warm to room temperature. The reaction mixture was stirred at ambient temperature overnight. The reaction was quenched with ice-water and acidified with hydrochloric acid (10%) to pH 4. The solution was then extracted with dichloromethane. The organic layer was collected, washed with brine, and dried over magnesium sulfate. After removal of solvent, the residue was purified by silica gel column chromatography eluting with ethyl acetate in hexane to provide the compound as a white solid (99, 12 mg, 2%). MS (ESI) [M−H+]=369.09.

Provenance & Evidence