Thermolysis of 1,3-dioxin-4-ones: Fast generation of kinetic data using in-line analysis under flow

Thierry Durand (1, 2, 3, 4) , C. Henry (5, 6) , D. Bolien , D.C. Harrowven , S. Bloodworth , Xavier Franck (7) , R.J. Whitby

1 IBMM - Institut des Biomolécules Max Mousseron [Pôle Chimie Balard]
2 CNRS - Centre National de la Recherche Scientifique
3 UM1 - Université Montpellier 1
4 UM2 - Université Montpellier 2 - Sciences et Techniques
5 Fondation FondaMental [Créteil]
6 Hôpital Albert Chenevier
7 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse

Rapid acquisition of kinetic data is demonstrated with a commercial meso-scale flow reactor, using a step-change in flow rate or ‘push-out’ from the flow line. For thermolysis of 1,3-dioxin-4-ones (1), we obtain excellent reproducibility in the activation energies measured from spectroscopic data collected by in-line UV or transmission FT-IR monitoring of the output during the transitional period between two flow rates (±3 kJ mol−1, 0.7 kcal mol−1). Analysis of multi-component UV and IR data is conducted using an orthogonal projection approach (multivariate curve resolution by alternating least squares) for complex spectra, or by calibration-less integration of non-overlapping peak absorbance. All analysis methods were validated using off-line 1H NMR analysis, and kinetic parameters obtained using the method of a flow rate step-change were validated against conventional steady-state measurements in which time-series data were acquired across multiple experiments. Thermal transfer and dispersion effects are addressed. The experimental methods described herein are valuable for accelerated reaction study and in process development.

Domains: Chemical Sciences

Thierry Durand, C. Henry, D. Bolien, D.C. Harrowven, S. Bloodworth, et al.. Thermolysis of 1,3-dioxin-4-ones: Fast generation of kinetic data using in-line analysis under flow. Reaction Chemistry & Engineering, 2016, 1 (1), pp.82-89. ⟨10.1039/C5RE00007F⟩. ⟨hal-02046204⟩