Carbon Dioxide → 1H-pyrrolo[2,3-b]pyridin-4-ol

Participants

Reaction Conditions

Reaction Steps

4-Chloro-1H-pyrrolo-[2,3-b]pyridine [80 g, Reference Example 64] was treated with 10% aqueous sodium hydroxide solution (330 g) and heated to 180° C. for 8 hours in a parr bomb with magnetic stirring. The reaction mixture was cooled to room temperature and excess sodium hydroxide was neutralized with a large excess of solid carbon dioxide pellets. Undissolved starting material was removed by filtration and the filtrate was concentrated in vacuo. The residue was extracted with hot methanol (3×1000 mL). The combined methanol extracts were concentrated and the residue purified by flash column chromatography on silica gel eluting with a mixture of dichloromethane and methanol (9:1 v:v to 4:1 v:v) to afford the title compound as a solid (63 g). TLC: RF=0.32 (dichloromethane/methanol 4/1).

Provenance & Evidence