Water → 5-Fluorouracil

Temperature

80 °C

Into a "Daiflon" resin (polytriflurochloroethylene manufactured by Daikin Kogyo, Co., Ltd.) made flask equipped with a stirrer, a cooler, a gas inlet and a therometer, a solution of cytosine (1.11 g; 10 mmol) in water (50 ml) was charged, and fluorine gas (34%; diluted with nitrogen) was blown therein at 18° to 20° C. until the cytosine was consumed completely. The reaction was finished in 60 minutes, and the total amount of fluorine used was 35 mmol. The reaction mixture (pH, <1) was adjusted to pH 6.0 with an aqueous solution of sodium hydroxide and heated at 80° C. for 4 hours. After removal of the solvent while heating under reduced pressure, the residual pale brown solid was extracted with ethanol and recrystallized from water to give 5-fluorouracil (0.85 g). Yield, 65%. M.P. 282°-283° C. (decomp.). UV absorption spectrum: λmaxpH 2 266 nm; λmaxpH 10.5 269 nm. Thin layer chromatography: Rf 0.60. Paper chromatography: Rf 0.54.

1. customequipped with a stirrer
2. customat 18° to 20° C. until the cytosine was consumed completely
3. customAfter removal of the solvent
4. temperaturewhile heating under reduced pressure
5. extractionthe residual pale brown solid was extracted with ethanol
6. customrecrystallized from water

ORD record

ord-be0eda15e5ca4462a55d512c392cbc0e

Source dataset

uspto-grants-1978_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04122251