Toluene → 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 (1.80 g, 4.93 mmol, from Step 1), di-tert-butyl hydrazine-1,2-dicarboxylate (1.3 g, 5.4 mmol, Aldrich) and Cs2CO3 (1.6 g, 4.9 mmol, Aldrich) were combined in toluene (20 mL, 200 mmol) and dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine-(2′-aminobiphenyl-2-yl)(chloro)palladium (1:1) (0.39 g, 0.49 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 3.5 hours. The reaction was cooled to room temperature, water was added and the product was extracted with five portions of EtOAc. The combined extracts were dried over sodium sulfate, filtered and concentrated. Flash chromatography, eluting with a gradient from 0-50% EtOAc in hexanes afforded product as a yellow foam (2.11 g, 76%).

Provenance & Evidence