INDICATOR COMPOUNDS, METHODS OF THEIR PREPARATION AND USE OF THOSE COMPOUNDS IN AN IRON ASSAY SYSTEM

摘要

The present invention is related to compounds of the general formula (I) (I) wherein R1 denotes hydrogen, halogen or C1-C4 alkyl, R2 denotes C1-C4 alkyl, aryl or heteroaryl, or a substituted C1-C4 alkyl, aryl or heteroaryl and X denotes hydrogen or Na and their preparation. The compounds can be used in an iron assay system.