Emrys

Fig. 16.7. A pressure vessel in action - tfie boiler of the articulated steam locomotive Merddin Emrys, built in 1879 and still hauling passengers on the Festiniog narrow-gauge railway in North Wales.

Juhasz, G., Kekesi, K., Emri, Z., Soltesz, I. Crunelh, V. (1990). Sleep-promoting... 

The production of 13CC>2 from [13C]-deca-BDE degradation was analyzed using the technique of gas chromatography coupled to mass spectrometer for isotope ratio (GC-EMRI). This technique measures the isotopic ratio 13C/12C of CO2 in the gas phase with respect to an international standard V-PDB (Vienna Pee Dee Belem-nite). This isotopic ratio is reported in 8 notation relative to an international standard per mil (%o) ... 

Until 2004, Biotage (formerly Personal Chemistry) offered the Emrys monomode reactor series of instruments (Fig. 3.19). Although no longer commercially available, many instruments are currently still in use. Therefore, this line of products is discussed in detail in this chapter [15]. 

The Emrys Creator is the basic application tool for reactions on a 0.5-5.0 mL scale. The Emrys Optimizer allows for automation with integrated robotics so that... 

Fig. 3.19 Personal Chemistry (Biotage) Emrys product series Creator,...

Reaction control is temperature-based, with the system trying to attain the adjusted maximum temperature as rapidly as possible. When employing polar reaction mixtures with a high level of absorption, the output power can be limited to a maximum of 150 W to avoid overheating of the sample. The instmments of the Emrys series come with a comprehensive software package for the creation of protocols, including an ISIS draw surface for graphical description of the reactions. 

A very useful tool is the Emrys Knowledge Database, representing a collection of detailed protocols for reactions performed with Biotage (Personal Chemistry) instmments. To date, this web-based tool contains around 4000 entries. 

Similar to its predecessors of the Emrys series, the operation limits for the Initiator system are 60-250 °C at a maximum pressure of 20 bar. Temperature control is achieved in the same way by means of an IR sensor perpendicular to the sample position. Thus, the temperature is measured on the outer surface of the reaction vessels, and no internal temperature measurement is available. Pressure measurement is accomplished by a non-invasive sensor integrated into the cavity lid, which measures the deformation of the Teflon seal of the vessels. Efficient cooling is accomplished by means of a pressurized air supply at a rate of approximately 60 L min-1, which enables cooling from 250 °C to 40 °C within one minute. 

The above mentioned Knowledge Database has been adapted for use with the Initiator System as the technical features of the new instruments are very similar to those of the Emrys series. 

As a starting point for reaction optimization, Biotage offers a microwave reaction database (Emrys PathFinder) with ca. 4000 validated entries for microwave chemistry performed with Biotage single-mode instruments. 

A prototype of a microwave reaction vessel that takes advantage of bottom filtration techniques was presented by Erdelyi and Gogoll in a more recent publication. Therein, the authors described the use of a modified reaction vessel (Fig. 7.2) for the Emrys instruments (see Section 3.5.1) with a polypropylene frit, suitable for the filtration /cleavage steps in their microwave-mediated solid-phase Sonogashira coupling (see Scheme 7.19) [21]. 

Fig. 7.2 Modified microwave vial for use in the Emrys series (reproduced with permission from [21]).

As illustrated in Scheme 1, on a small scale under reflux in ace-tone/water, 5% of starting material remained after 12 h reaction time and approximately 20% of the by-product was formed (entry 1). When performing the reaction at the same concentration in a lab-scale micro-wave device (Emrys Optimizer, entry 2) at 120°C, the reaction was complete after 5 min and gave a product of significantly higher purity and in higher yield. In the next step, 400 ml of reaction mixture was reacted in an 8 vessel rotor batch microwave (entry 3) at the same temperature... 

In various experiments, it was shown that the use of microwave technology leads to a significant decrease in the reaction time and in some cases also to less by-product and a higher yield. This technology allowed us to optimize the reaction with focus on work-up and purification, independent of reaction temperature and boiling point of the solvent. In most cases the reaction conditions, applied on 15 ml scale in the Emrys Optimizer, were transferred without further optimization to the microwave reactors tested and led to comparable results. Additional optimization in a few cases was limited to small adjustments in reaction temperature or reaction time. A number of scale-up experiments were conducted using a Synthos 3000 reactor and we showed that a scale-up to 100 g is feasible. 

Juhasz G, Emri Z, Kekesi KA, Salfay 0, Crunelli V. (1994). Blockade of thalamic GABAB receptors decreases EEG synchronization. Neurosci Lett. 172(1-2) 155-58. 

The numtrer next to each point corresponds to emries In Table 2-1. 

JOZSEF EMRI and BE=LA GYORI Lajos Kossuth University, Debrecen, Hungary... 

---