N-Iodosuccinimide → 1-benzyl-6-[4-fluoro-3-(methoxycarbonyl)phenyl]-3-iodo-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid

Participants

Reaction Steps

Sodium hydrogen carbonate (11.39 g/0.136 mol) and N-iodosuccinimide (30.51 g/0.136 mol) are added portionwise to a suspension of 1-benzyl-6-[4-fluoro-3-(methoxycarbonyl)phenyl]-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid (14.25 g/45.2 mmol) in 410 mL of dioxane. The reaction mixture is stirred for 24 h at ambient temperature. The reaction medium is run into a saturated aqueous solution of NaHCO3. The aqueous phase is washed with EtOAc and then acidified to pH=2-3 using a solution of KHSO4 (1 M), and extracted with EtOAc. The organic phase is washed with water, with a solution of sodium thiosulphate (0.1 M) and with a saturated aqueous solution of NaCl, dried over sodium sulphate and then concentrated to dryness to give 13.9 g of a yellow powder (yield: 70%).

Provenance & Evidence