Ammonia → 5,6-Dichloro-2-cyclopropylpyrimidine-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (14 mL, 23 g, 0.15 mol) and 5-chloro-2-cyclopropyl-1,6-dihydro-6-oxo-4-pyrimidinecarboxylic acid (i.e. the product of Step B1 or B2) (75 g, 300 mmol) were combined and heated at 85° C. for 3 h. The reaction mixture was cooled to 30° C. and added over 30 minutes to a mixture of acetonitrile (50 mL) and ice water (80 mL), with the temperature maintained at 5-10° C. and the pH maintained in the range 1-3 by co-feeding aqueous ammonia (28%). The pH was adjusted to about 2, the mixture was concentrated at 25° C. with a rotary evaporator to remove acetonitrile, and the precipitated product was isolated by filtration and washed with water (2×25 mL). The solid was dried in a vacuum oven to afford the title compound (ca. 7.0 g).

Provenance & Evidence