Multivariate analysis of inline benchtop NMR data enables rapid optimization of a complex nitration in flow

Abstract

Inline benchtop NMR analysis is established as a powerful tool for reaction monitoring, but its capabilities are somewhat limited by low spectral resolution, often leading to overlapping peaks and difficulties in quantification. Using a multivariate analysis (MVA) statistical approach to data processing these hurdles can be overcome, enabling accurate quantification of complex product mixtures. By employing rapid data acquisition (2.0 s recording time per spectrum), we demonstrate the use of inline benchtop NMR to guide the optimization of a complex nitration reaction in flow. Accurate quantification of four overlapping species was possible, enabling generation of a robust DoE model along with accurate evaluation of dynamic experiments.