MONITORING THE PRODUCTS OF CONDENSATION OF 4-NITROBENZOYL CHLORIDE AND 2,4-DIAMINOBENZENESULPHONIC ACID BY ION-PAIR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple and rapid high-performance liquid chromatographic method for monitoring the process of condensation between 2,4-diaminobenzenesulph onic acid and 4-nitrobenzoyl chloride was developed. The reaction prod ucts were separated on a reversed-phase Novapak C-18 column using 5 mM tetrabutylammonium hydrogensulphate-acetonitrile (77.5:22.5, v/v) as the eluent. The method was used not only for checking the quality of t he condensed products but also for optimization of the process conditi ons. The method was validated by monitoring several batches of laborat ory scale reactions and used successfully for upgrading them to plant level. (C) 1997 Elsevier Science B.V.