Abstract: 3-Alkyl- or fluoroalkyl-3-(4-pyridyl)piperidine-2,6-diones, useful in the treatment of breast cancer, of formula ##STR1## wherein R represents an alkyl group having 2 to 10 carbon atoms or a fluoroalkyl group having 2 to 5 carbon atoms and A is hydrogen or an alkyl group having 1 to 4 carbon atoms, are prepared by reacting a 4-pyridylacetate with an alkyl or fluoroalkyl iodide, chloride or bromide, in the presence of a sterically bulky base and reacting the product with acrylamide in the presence of a sodium or potassium branched chain alkoxide. Preferably potassium t-butoxide is used in both stages and they are carried out sequentially at room temperature in an alcoholic or polar, aprotic solvent in a single reaction vessel.