Hydrofluoric Acid → 5-Fluorouracil

Participants

Reaction Steps

Into a solution of cytosine (11.1 g) in hydrogen fluoride (50 ml) kept at 5° C., fluorine fluorosulfonate was blown while stirring. The cytosine was completely consumed in 2 hours, and the total amount of fluorine fluorosulfonate was 0.21 mol. The reaction mixture was heated to distill out the hydrogen fluoride, water (100 ml) was added thereto, and the resulting mixture was heated under reflux for 2 hours. An aqueous solution of calcium hydroxide was added thereto to make pH 6, and precipitated materials were eliminated by filtration. The filtrate was cooled, and the separated crystals were collected by filtration to give 5-fluorouracil (9.9 g). Yield, 76.2%.

Provenance & Evidence