Hydrochloric Acid → 5-Chloro-2-cyclopropyl-1,6-dihydro-6-oxo-4-pyrimidinecarboxylic acid

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Reaction Conditions

Reaction Steps

A 500 mL multi-neck flask with overhead stirrer, thermocouple and addition funnel was charged with 2-cyclopropyl-1,6-dihydro-6-oxo-4-pyrimidinecarboxylic acid (36 g, 0.20 mol), water (70 mL) and 50 wt. % aqueous NaOH (14.4 g, 0.18 mol). The mixture was stirred at 10° C., and 10.3% aqueous NaOCl (160 g, 0.22 mol) was added over 1.5 h with cooling to maintain the reaction mixture at 10° C. The mixture was cooled to 5° C., and sodium sulfite was added until KI-starch paper gave negative test results. Hydrochloric acid (37 wt. % in water, 44.3 g, 0.443 mol) was added at 5° C. over about 30 minutes to lower the pH to 0.8. The mixture was filtered, and the collected solid was washed with cold 1 N HCl (20 mL), and dried to constant weight in a vacuum-oven at 50° C. to give 40.9 g (95% yield) of the title compound as a solid melting at 189-190° C.

Provenance & Evidence