Cesium carbonate → di-tert-butyl 1-[2-(ethoxycarbonyl)-1-(phenylsulfonyl)-1H-pyrrolo[3,2-b]pyridin-5-yl]hydrazine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl 5-chloro-1-(phenylsulfonyl)-1H-pyrrolo[3,2-b]pyridine-2-carboxylate (2.15 g, 5.89 mmol, from Step 1), di-tert-butyl hydrazine-1,2-dicarboxylate (1.5 g, 6.5 mmol, Aldrich) and Cs2CO3 (1.9 g, 5.9 mmol, Aldrich) were combined in toluene (30 mL) and dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine-(2′-aminobiphenyl-2-yl)(chloro)palladium (1:1) (0.46 g, 0.59 mmol, Aldrich) was added. The mixture was degassed by a stream of nitrogen through the solution for 10 minutes. The reaction was stirred at 110° C. for 3 hours. Upon cooling to room temperature, water was added and the product was extracted with three portions of EtOAc. The combined extracts were dried over sodium sulfate, filtered, and concentrated. Flash chromatography, eluting with a gradient from 0-40% EtOAc in hexanes afforded product as a yellow foam (2.54 g, 77%).

Provenance & Evidence