Sulfuric Acid → 2,6-Dichloro-5-fluoronicotinamide

Participants

Reaction Conditions

Reaction Steps

The amide was prepared from the 2,6-dichloro-5-fluoro-3-cyanopyridine described in Example 1b. The cyanopyridine was placed in 12 L flask, cooled to 5°-10° C. in an ice bath, and 2300 mL of concentrated sulfuric acid was added. The residual DCE was then removed under vacuum at room temperature. After removal of the DCE the mixture was heated at 65°-70° C. for 1-2 hours and monitored by HPLC. After about 2 hours the mixture was cooled to about 10° C. in an ice bath. The amide product (3) formed was used directly for the next step without isolation or purification.

Provenance & Evidence