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

Participants

Reaction Conditions

Reaction Steps

Benzyl 1-benzyl-6-[4-fluoro-3-(methoxycarbonyl)phenyl]-1H-pyrazolo[3,4-b]pyridine-4-carboxylate (12.0 g/24.2 mmol) is dissolved in 100 mL of concentrated sulphuric acid. The solution is heated at 50° C. for 1 hour. The reaction mixture is then slowly run into ice-cold water and extracted with EtOAc. The organic phase is washed with water and then with a saturated aqueous solution of NaCl, dried over sodium sulphate and concentrated to dryness to give 6.25 g of a yellow-orange powder (yield: 82%).

Provenance & Evidence