A process for preparing 5-fluorouracil, and a novel starting compound for such process, are disclosed. The novel starting compound is 2,4,5-trifluoropyrimidine. The process comprises hydrolyzing the 2,4,5-trifluoropyrimidine at a temperature of about 2.degree. to about 100.degree. C., thereby directly producing the compound 5-fluorouracil. 5-Fluorouracil is a known anti-tumor agent, which has been used in the treatment of various types of cancers. In addition, 5-fluorouracil is a starting material for the production of certain types of pro-drugs, which are metabolized to form 5-fluorouracil in the body, such as, for instance, the compound 1-(2-tetrahydrofuryl)-5-fluorouracil.