The Kolbe-Schmitt synthesis from resorcinol was exemplarily investigated to figure out the process intensification potential of continuous processing in the milli and micro scale, alone and combined with additional intensification means like alternative solvents, new reagents and an advanced reactor design. The oil bathheated synthesis was investigated for capillary reactors of different dimensions, using aqueous solutions of KHCO 3 and reactive ionic liquids. Already the first case led to space-time yields (STY) of 15,500 kg/(m 3 h) at 37 % yield. Synthesis with different CO 2 -donating salts showed that KHCO 3 has the highest activity and that hydrogen carbonates are better than carbonates. The replacement of KHCO 3 by reactive ionic liquids led to a substantial increase, both in yield (58 %) and STY (69,900 kg/(m 3 h)). The application of scCO 2 did not significantly increase the yield despite an even more substantial change of the reaction medium. Using an electrically heated microstructured reactor resulted in a tenfold higher productivity (0.75 t/a) compared to the capillary reactor and does much better ensure scalability of the reaction.

A compact lab plant was designed for the continuous-flow synthesis of fluorine-containing compounds and was combined with an NMR analysis platform based on a benchtop NMR spectrometer. The approach of a unified synthesis and analysis strategy for fine chemicals was applied to three different reactions, all employing fluorine as a chemical probe for online-19F NMR analysis. A high temperature synthesis for the deprotection of a CF2H group was done as well as Ruppert–Prakash reactions for the perfluoroalkylation of benzaldehyde as a model substrate. The C–H arylation of furan with a trifluoromethylated aryldiazonium salt was performed as an example of a photochemically catalyzed reaction. All three reaction classes challenge the synthesis and analysis setup differently according to sample preparation (premagnetization of bubble-free sample) and spectrometer sensitivity (signal to noise ratio, spectral resolution, scan number, substrate concentration and flow rate), but nonetheless prove the successful application of the continuous-flow synthesis of fluorinated fine chemicals with integrated online NMR analysis

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