Microreactor multiplicity

The redispersion microreactor is applied for the liquid-liquid polycondensation to yield an OLED material by multiple Suzuki coupling. As the initial test reaction, the following single Suzuki coupling is currently being explored in the liquid-liquid system made from water/ dioxane/toluene. 

The resin-bound trienes 83 (Scheme 11) were prepared in a similar fashion to the solution-phase studies (Sect. 2.2.2) and underwent tandem RCM resin-cleavage to liberate four macrolactones 84a,b and 85a,b in a combined yield of 52%. Although, as expected, a large amount of initiator 3 was required to effect this transformation, the procedure constituted a novel and efficient route to the epothilones which paved the way for the generation of a library of epothilone analogs. The library synthesis was achieved using the recently developed SMAR-I9 microreactors (SMART=single or multiple addressable radiofrequency tag) [25] (Scheme 12). 

Microreactors for multiple parallel reactions, either fast or long Semi-batch systems similar to titer-plates connected to microdispensing systems and separation/analysis units... 

Jackman, R.J., Queeney, K.T., Herzig-Marx, R., Schmidt, M.A., Jensen, K.F., Integration of multiple internal reflection (MIR) infrared spectroscopy with silicon-based chemical microreactors. Micro Total Analysis Systems, Proceedings 5th Y7AS Symposium, Monterey, CA, Oct. 21-25, 2001, 345-346. 

Scheme 4.89 Two examples of microreactor loaded into a dedicated microchip and circulates PCR devices (a) Sample is continuously pumped multiple times through the temperature zones by through the flow cell and encounters different heat convection and gravity (g). Reprinted with temperature regions (resp. 55, 72 and 95 °C). permission from [383]. Copyright 2007 Wiley-Reprinted with permission from [377]. Copyright VCH Verlag GmbH.

In comparison to the conventional automated synthesis, the radiochemical yield and purity of the compound obtained by microreactor processing was higher and also had shorter synthesis time [21]. Multiple doses of2-deoxy-2-[18F]fluoro-D-glucose for positron emission tomography imaging studies in mice were prepared. Today, 2-deoxy-2-[18F]fluoro-D-glucose is routinely produced in about 50 min with the use of... 

Lonza Ltd in Visp, Switzerland, performed the reaction of an acid chloride with phenylethyl magnesium bromide in THF in a multiple-injection microreactor [35], Many injection points were chosen to split and delocalize the reaction and heat release so that several small hot spots arise instead of having one large hot spot (AH = —260kJ/mol, A7 = about 70 °C). The reaction is quenched at the reactor outlet with water. 

To eliminate uncertainties associated with distribution of the reaction mixture to multiple parallel microchannels, and to eliminate associated axial dispersion in the necessary distribution and collection headers, a single channel microreactor was constructed of commercially available tubing. The criteria that governed the selection of the reactor and other tubing dimensions included ... 

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