Continuous-flow synthesis of highly functionalized imidazo-oxadiazoles facilitated by microfluidic extraction

• Ananda Herath and
• Nicholas D. P. Cosford

Beilstein J. Org. Chem. 2017, 13, 239–246, doi:10.3762/bjoc.13.26

• single-step liquid–liquid microextraction unit to remove high boiling point polar solvents and impurities and provides the target compounds in high purity with excellent overall yields. Keywords: imidazo[1,2-a]pyridine; imidazo[1,2-a]pyridin-2-yl-1,2,4-oxadiazole; liquid–liquid extraction module

• microfluidic liquid–liquid extraction module (the AFRICA® FLLEX) was incorporated at the end of the flow sequence to remove the high boiling point solvent (DMA). Initial studies using a single microreactor and dichloromethane as the organic extraction phase demonstrated proof-of-concept that the microfluidic

Ethyl diazoacetate synthesis in flow

• Mariëlle M. E. Delville,
• Jan C. M. van Hest and
• Floris P. J. T. Rutjes

Beilstein J. Org. Chem. 2013, 9, 1813–1818, doi:10.3762/bjoc.9.211

• phase separation ideally had to be performed in flow as well. Therefore, a Flow-Liquid–Liquid-Extraction module (FLLEX) [25] was connected to the system [26][27]. The module utilizes a hydrophobic Teflon membrane and two back-pressure regulators (BPRs) to create a pressure difference, which causes the

• CH2Cl2 meaning 409 mg of pure EDA. Schematic representation of the microreactor setup. Univariate optimization using 30 s, 15 °C and 1.5 equiv NaNO2 as standard. 2D-Contour plots of the multivariate optimization. Phase separation using a Flow-Liquid–Liquid-Extraction module (FLLEX) directly coupled to