FREMGANGSMAADE TIL FREMSTILLING AF SUBSTITUEREDE PYRIMID-2-ONER ELLER SALTE DERAF

Compounds of general formula: (I) (wherein X represents a halogen atom or a trifluoromethyl group; R1 and R2, which may be the same or different, each represents a hydrogen atom, or a C1-4 alkyl group, and R3 represents a hydrogen atom or a C1-5 saturated or unsaturated, straight or branched acyclic aliphatic group; a C3-8 saturated or unsaturated cyclic aliphatic group; a heterocyclic substituted aliphatic group; an araliphatic group; or a heterocyclic or carbocyclic aryl group; any of said groups optionally carrying one or more substituents selected from halogen, oxo, hydroxy, mercapto, C1-4 alkyl, C1-4 alkoxy, C1-4 alkanoyloxy and amino) and, where an acidic or basic group is present, physiologically compatible salts thereof have been found to be of use in combating abnormal cell proliferation. The compounds of formula I may be prepared by reaction of a 5-halo- or 5-trifluoromethyl-pyrimidin-2-one with an appropriate isocyanate.