2,6-Dichloro-5-fluoronicotinamide

Использование

2,6-Dichloro-5-fluoronicotinamide is a fluorinated pharmaceutical intermediate compound used in the synthesis of Sotorasib and AMG 510. Sotorasib is a RAS GTPase family inhibitor used for the treatment of KRAS-mutated solid tumours including non-small cell lung cancer (NSCLC) and colorectal cancer.

Синтез

A reaction vessel added 2000 mL of phosphorus oxychloride (POCl). The vessel was cooled to 5°-10° C., and 500 g of dry 2,6-Dihydroxy 5-fluoro-3-cyanopyridine was added in portions at a temperature below 30° C. The mixture was heated at 80°-85° C. for 60 minutes and cooled to room temperature. Phosphorus pentachloride (PCls), 2200 g, was added, in portions, to the mixture. After the addition was complete, the mixture was heated to 100°-104° C. The reaction was stopped after about 30 hours. The mixture was cooled to room temperature, and POCl was removed under reduced pressure. 1,2-Dichloroethane (DCE), 2.0 L, was added to the residue, and the mixture was cooled to 5-10°C. in an ice bath. Distilled water, 5000 mL, was added slowly to the mixture, maintaining the temperature below 40°C. After the water addition, the mixture was stirred at room temperature for an hour. The 1,2-dichloroethane (DCE) layer was separated, and the aqueous layer was extracted with DCE. The DCE extracts were combined. The DCE was removed by vacuum distillation. The residual 2,6- dichloro-5-fluoro-3-cyanopyridine product is used in situ for the next step. 2,6- dichloro-5-fluoro-3-cyanopyridine was placed in a 12 L flask, cooled to 5-10°C. in an ice bath, and added 2300 mL of concentrated sulfuric acid. 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 further purity obtained 2,6-Dichloro-5-fluoronicotinamide.