CARBONATE ESTERS AND DOUBLE ESTERS - OPTIMIZATION USING STATISTICAL DESIGN AND ANALYSIS - MONITORING BY FIBEROPTIC NIR SPECTROSCOPY

Statistical experiment design and analysis have been applied to a study of the synthetic transformation of an acid into a double ester. The objectives were to explore the influence of those independent variables and their interactions which were expected to influence the synthetic reaction. The model obtained was used to predict optimal conditions, in order to establish a high-yielding synthetic procedure for making 1-(ethoxycarbonyloxy)ethyl 5-acetamido-3-(N-methylacetamido)-2,4,6-triiodobenzoate, a substance of interest as an X-ray contrast agent for the medical imaging of the liver. A new technique based upon fiber-optical near infrared spectroscopy and principal components analysis has been developed and applied to monitor the concentration profile over time for the synthetic reaction and to determine the optimal reaction time.