Drivers for Performing Aromatic Nitrations in Micro Reactors

1 Drivers for Performing Aromatic Nitrations in Micro Reactors 

Most nitrations are highly exothermic and hence release a lot of reaction heat for most experimental protocols [37, 94]. This high exothermicity may even lead to explosions [37, 38]. Nitration agents frequently display acid corrosion [37]. For these reasons, nitrations generally are regarded as being hazardous [37, 38]. 

Owing to the heat release, nitrations often lack selectivity, i.e. many parallel, consecutive and decomposition processes are known to occur. As a result, product spectra are unusually wide and consequently yields and purity are low [37, 94]. 

The selectivity issue has been related to multi-phase processing [31]. Nitrations include both organic and aqueous phases. Oxidation to phenol as one side reaction takes places in the organic phase, whereas all other reactions occur in the aqueous phase and are limited by organic solubility. For this reason, enhancing mass transfer by large specific interfaces is a key to affecting product selectivity. 

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