Potassium Hydroxide → 5-Fluoro-1-(3-fluorobenzyl)-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid

Participants

Reaction Steps

A mixture of 6.9 g (20.58 mmol) of 5-fluoro-1-(3-fluorobenzyl)-1H-pyrrolo[2,3-b]pyridine-2-ethyl carboxylate (WO07/010,138) and 1.89 g (33.7 mmol) of potassium hydroxide in a mixture of 80 mL of ethanol and 10 mL of water is heated under reflux for 1.5 h. After this time, the reaction mixture is concentrated at reduced pressure, and is then taken up in 200 mL of water. The solution is acidified with additions of concentrated hydrochloric acid, and then extracted three times with 50 mL of dichloromethane. The organic phases are combined, dried over sodium sulfate and then concentrated at reduced pressure. The resultant product is triturated in 5 mL of dichloromethane. A precipitate is collected by filtration and is dried at reduced pressure. In this way we isolate 5.35 g of the expected product, which is used as it is in the rest of the synthesis.

Provenance & Evidence