Nitric Acid → HCID 178526744, compound

Participants

Reaction Conditions

Reaction Steps

250 mL (5 volumes) of concentrated sulfuric acid was stirred in a 1000 mL round bottom flask (22° C.). To this, 2-amino-6-chloro-4-pyrimidinol (50 g) was added in portions. The temperature increased rapidly with early additions, stabilizing at a temperature of 40° C. Later additions had less effect on the temperature, a maximum of approx. 45° C. being recorded. Prior to addition of fuming nitric acid (45 mL, 0.9 volumes), the mixture was cooled (using an ice bath) to 20° C. In portions of roughly 1.5 mL (reflecting pipette volume), nitric acid was added dropwise at a steady rate (ca. 1 min between each portion). Early portions had the greatest effect on the temperature, the controlled exotherms reaching a temperature of approx. 26° C. before returning to 20° C. under the influence of the ice bath. Later portions had little effect, and the temperature was maintained at approx. 21° C. After 45 mL of fuming nitric acid had been added in this way, the mixture was allowed to stir for 2 hr (during this period the ice bath was removed and the temperature stabilised at room temperature ca. 22° C.). The entire mixture was poured onto stirred ice/water (1200 mL) and the resulting yellow solid filtered under vacuum. The product was washed in succession with water (600 mL), ethanol (600 mL) and diethylether (600 mL). This method gave 63.5 g (98% yield) of the required nitro-pyrimidinol.

Provenance & Evidence