Pyruvic Acid → 5-Fluoro-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

0.5 g (2.10 mmol) of 2-amino-3-iodo-5-fluoropyridine obtained in Stage 5.1, 0.55 g (6.3 mmol) of pyruvic acid, 0.71 g (6.3 mmol) of 1,4-diazabicyclo[2.2.2]octane (DABCO) and 15 mL of anhydrous dimethylformamide are introduced into a 25-mL sealed tube, equipped with a magnetic stirrer and bubbled with argon. After some minutes, 0.05 g (0.22 mmol) of palladium acetate is added. The reaction mixture is stirred and bubbled with argon for 20 minutes, then it is quickly sealed and heated to 100° C. for 2.5 h. The cooled solution is concentrated at reduced pressure. The residue is then taken up in ethyl acetate (100 mL) and water (75 mL). The organic phase is washed with water then extracted with 2×50 mL of aqueous solution of 2N sodium hydroxide. The basic aqueous phases are combined, cooled to 0° C. then acidified by adding hydrochloric acid (pH 3). The mixture is extracted with ethyl acetate (4×50 mL), the combined organic phases are dried over sodium sulfate and then concentrated at reduced pressure. We obtain 0.158 g (0.88 mmol) of the expected product in the form of a yellow powder.

Provenance & Evidence