Direct Fluorination of Aliphatics and Non-C-Moieties

The basic limitations of direct fluorinations are similar for aliphatic compounds as discussed already using the example of aromatic derviatives and so is the potential of microreactors. The fluorination of ethyl acetoacetate was carried out in an annular-flow microreactor 

The microreactor contained a single channel single-channel microreactor with two feeds for gas and liquid [123,124]. The gas flows were set so high that an annular flow regime was reached with a central gas core surrounded by a liquid film wetting the channel. This flow pattern has a very high interface and low liquid-side resistance due to the thin film. Formic acid was used as solvent. 

High yields of the mono-fluorinated product at short reaction times were obtained which exceeded the performance of standard batch laboratory processing [122]. Yields of 72% were achieved at 99% conversion [122,123]. The metallic construction 

This microflow processing was demonstrated also fluorination of /3-ketoesters such as ethyl 2-chloro-3-oxobutanoate [122,123] or ethyl 2-methyl-3-oxobutanoate [123]. Five- and six-ring /3-ketoester derivatives such as 3-acetyl-3,4,5-trihydrofuran-2-one (1) [123], 2-acetylcyclohexan-one [123], and ethyl 2-oxocydohexane carboxylate (2) [123] were directly fluorinated as well. 

The performance of a single-channel and a numbered up three hannel microreactor was similar [123]. Some differences were found which probably origin more from fluctuations in the hydrodynamics rather than from the numbering up. 

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Direct fluorination of aliphatics and non-C moieties Direct fluorination of benzenoid aromatics Direct fluorination of heterocyclic aromatics Oxidations of alcohols, diols and ketones with fluorine Photo-oxidation of a-terpinene and cyclopentadiene Oxidation of benzyl alcohol to benzaldehyde Homogeneously catalyzed oxidation of butyraldehyde Oxidation of sulfite to sulfate Photochlorination of aromatic isocyanates... 

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