5-pyrazolone compounds which are substituted with a thioether group in the 4-position may be prepared by the reaction of a 5-pyrazolone compound which is unsubstituted in the 4-position with a sulphenic acid amide. The resulting 5-pyrazolone compounds substituted in the 4-position are suitable for use as 2-equivalent magenta couplers in color photographic recording materials.