Ethanol → HCID 67088931, compound

Participants

Reaction Steps

A solution of DIAD in THF (10 mL) was added slowly via a syringe pump under N2 at room temperature for 1 hour to a solution of tert-butyl 3-hydroxy-5-nitro-1H-pyrazolo[3,4-b]pyridine-1-carboxylate (0.35 g, 1.2 mmol), EtOH (0.069 g, 1.5 mmol), and PPh3 (0.49 g, 1.9 mmol). The reaction mixture was poured onto water (20 mL) and extracted with EtOAc. The combined organic layers were washed with brine, dried over MgSO4, and concentrated under reduced pressure to give the crude material. The crude material was treated with MeOH to give tert-butyl 3-ethoxy-5-nitro-1H-pyrazolo[3,4-b]pyridine-1-carboxylate as a precipitate. The filtrate was concentrated and treated with a solution (10:1 hexane:EtOAc) to precipitate triphenylphosphineoxide. Then, the filtrate was concentrated and flash chromatographed (SiO2, 10:1=hexane:EtOAc) to afford tert-butyl 3-ethoxy-5-nitro-1H-pyrazolo[3,4-b]pyridine-1-carboxylate (total 0.237 g, 62% yield). LRMS (ACPI pos) m/e 209.0 ((M-Boc)+1).

Provenance & Evidence