Ammonium Chloride → 1H-Pyrido[2,3-d]pyrimidine-2,4-dione

Participants

Reaction Conditions

Reaction Steps

A slurry of 2-aminonicotinic acid (10 g, 72.5 mmol), ammonium chloride (39 g, 725 mmol) and potassium cyanate (30 g, 362 mmol) in water (80 ml) was heated to 80° C. and maintained at this temperature with stirring for 30 minutes before being heated to 200° C. The mixture was stirred for 2 hours at this elevated temperature and then left to cool. Water (200 ml) was then added and the resultant mixture filtered. The solid was washed with hot water (100 ml) and then with cold water (2×100 ml) to give a yellow solid which corresponded to the title compound (11.79 g, 99%) in suitably clean form to be used without any further purification. m/z (LC-MSW, ESP):164 [M+H]+, R/T=2.11 mins.

Provenance & Evidence