Sulfuric Acid → 5-Chloro-6-fluoro-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione

Participants

Reaction Conditions

Reaction Steps

Combine 2-amino-5-fluoro-4-chloro-1-methyl-6-oxo-1,6-dihydropyridine-carbonitrile (4.97 g, 246 mmol) and 99% formic acid (40 mL, 8 volumes) in a dried vessel. Heat to 80° C. When a solution is formed add aqueous 9 N sulfuric acid (25 mL, 5 volumes). After 20 hours, cool ambient temperature and add ice-water (50 mL, 10 volumes) with stirring. Cool in an ice bath to give a solid. After 30 minutes, collect the solid by filtration, rinse with water (2×5 mL), and dry in vacuo to give the title compound.

Provenance & Evidence