Continuous production of chemical compounds by microreactor technology has proven to be a major benefit for many applications. FutureChemistry translates conventional batch processes to flow chemistry, identifies the critical parameters of a chemical process and optimizes them to ensure efficient synthesis.

1. Deprotection of p-methoxyphenyl (PMP) protected amines

Oxidative cleavage of the PMP group is a fast and exothermic reaction, which limits the feasibility of batch process up-scaling.

2. Selective α-ketone bromination

The synthesis of α-ketone bromides provides a good pathway towards α-substituted ketones through bromide substitution. Unfortunately direct α-ketone bromination with bromine limits batch scale-up.

3. Paal-Knorr pyrrole synthesis

The Paal-Knorr pyrrole synthesis can be used in the synthesis of furans and thiophenes. Due to its exothermic nature, the reaction is of not much use in the chemical industry.

4. Droplet Generation

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Chemical processes occurring on the fluid/fluid interface can be studied and enhanced by means of efficient droplet generation.

5. Synthesis of azides from amines

The synthesis of azides provides a good pathway towards triazoles through the Huisgen azide-alkyne cycloaddition but is dangerous, as the compounds tend to decompose violently under pressure or raised temperature.

7. Swern-Moffatt oxidation

The Swern-Moffatt oxidation is a highly valuable reaction, as it selectively oxidises alcohols to the corresponding aldehydes or ketones. In batch, the reaction requires a temperature of -78°C due to its high exothermic nature. At elevated temperatures, side product formation becomes dominant, except when very short reaction times are used. These short reaction times can be perfectly controlled in a continuous flow microreactor, and a minimum of 300 ms was obtained using the short quench microreactor.

8. Aldol condensation: synthesis of dibenzalacetone

The aldol condensation of benzaldehyde and acetone is a classical example of a spontaneous, exothermic reaction. Therefore in batch controlled reagent addition and cooling is needed.

9. Synthesis of azides from halides

The synthesis of azides is a key reaction in organic chemistry, as it provides a good pathway towards triazoles through the Huisgen azide-alkyne cycloaddition. Traditionally, this reaction is carried out using a variety of azide reagents, which can be explosive and release toxic gas.

10. Nitration of anisole

The nitration of aromatic compounds is a key reaction in organic chemistry. Conventionally, this reaction is difficult to control due to its exothermic character and the reagents’ high reactivity.

The dying of fabric using azo dyes in a continuous process is often performed by treating fabric with an aryl diazonium compound. This method circumvents the need for dissolving the dye, but suffers from the instability of the diazonium species.

12. Methylation with diazomethane

Reactions employing diazomethane as a methylating agent are very useful in organic synthesis, due to their high selectivity and yields. However, preparing diazomethane from one of the available precursor compounds requires much care, since it is a highly reactive species which can spontaneously explode on contact with sharp edges.

13. Wittig Reaction

A convenient and selective way of forming a carbon-carbon double bond is through the Wittig reaction and its modifications.

14. In situ generation of phosphonium ylides

Conventionally, the Wittig reaction is a two-step process, where the salt is treated with a base to obtain the reactive phosphonium ylide species, with subsequent workup and addition of the aldehyde. In batch, this two-phase system suffers from irreproducibility issues due to uncontrollable mixing behaviour.

15. Epoxidation Prilezhaev reaction of alkenes and formation of trans‐diols