Reaction, scale

I Secondary alcohols are oxidized by a variety of reagents to give ketones (Section 17.8). The choice of oxidant depends on such factors as reaction scale, cost, and acid or base sensitivity of the alcohol. 

The yield is variable depending on the degree of dryness ol CeCf, and the hydroxide contcm of thcC n5Li. b The N-N bond of 5 cannot be cleaved under the usual reaction conditions. Only when the pyrazolidine is deprotected. can the reduction be accomplished. c The yield is variable depending on the reaction scale. 

If the lithium borohydride sticks to the spatula or powder funnel, additional methanol can be used to wash the material into the reaction mixture without affecting the yield. On this reaction scale, an additional 25-50 mL of methanol could be used. Using 2.0M LiBH4 in THF instead of solid LiBH4 complicates the following step resulting in lower yields. 

The checkers obtained 0.849-0.875 g of catalyst, but II-NMR analysis revealed that the product was of low purity. Reactions run on a 0.75 mmol scale afforded the catalyst in 47-51% yield and in higher purity. Since the reaction is run in a sealed apparatus, the pressure built up in the apparatus (and therefore the boiling point and reaction temperature) may depend on the reaction scale and how far the flask is immersed into the oil bath. 

It is important to realize that though the formulas for RME explicitly do not depend on reaction scale, x, since this variable cancels out in the computation, RME does in fact implicitly depend on reaction scale because reaction yields are scale dependent and RME in turn depends on reaction yield. Reaction yields are parameters whose magnitude cannot be predicted theoretically but must be verified experimentally. It does not always follow that a reported yield for a given reaction at a given scale will be the same at another scale. This requires experimental verification. Moreover, the direction of change as the scale is changed is also not predictable. AH of this means that when the same synthesis plan is run at a different scale, different reaction yields will be determined and hence different material efficiency performance values of RME, Em and mass of waste will be obtained. However, the... 

Only a little effort is necessary to reduce solvent 1 demand used during reaction scale-up. The quantity used in the laboratory stage was reduced to 59% in the operation stage (Table 5.1). However, related to substrate 2, 96% of solvent 1 is still used. Thus, 87% of the original quantity of solvent will be fed to the incinerator for disposal, while the recycle rate is only 9.1% (from 96% to 87%, Table 5.1). Considering that there is a factor of five difference in solvent 1 demand between the operation scale and the literature procedure (see the segments Solvent of the mass index, in Figure 5.10), the potential for optimiz-... 

Reaction scale-up using the Voyager system in genuine continuous-flow format is achieved by the use of special coiled flow-through cells. The reaction coils are made of glass or Teflon (Fig. 3.24) with a maximum flow rate of 20 mL min-1 and operational limits of 250 °C or 17 bar. The continuous-flow format should only be used for homogeneous solution-phase chemistry, as slurried mixtures may cause prob-... 

Apart from the uses in the production of e-caprolactam, the Beckmann rearrangement has been used industrially in the synthesis of various APIs (Active Pharmaceutical Ingredient) or other compounds with economical value (essentially monomers for the production of polymers). A survey of the bulk reaction scaled in the GMP facilities at... 

The submitter and checkers have successfully performed this procedure on double the reaction scale [10 mmol of (+)-2], and obtained the product in 92% yield. 

Photolysis with ultraviolet light at 0°C on a 0.25-mmol reaction scale for ca. 1 hr. Isolated yields. 1.6 1 Mixture regioisomers. l 1 Mixture of regioisomers. 

Apply 100 pL of the transcriptional reaction mixture on top of the gel, and flush completely. If the reaction scale of the in vitro transcription is less than 100 pL, fill up the reaction mixture to 100 pL with sterilized distilled water before applying to the column. 

Reaction scale must deliver multi-100 mg quantities of material for further scaffold decoration work. 

Reaction scale < 100 g (dry reaction) < 100g up to 3000 g (depending on reactor type)... 

Appreciate the basic cost, safety, and efficiency concerns for increasing reaction scale... 

In the case of exothermic or endothermic reactions, scale-up may impair conditions for heat input or removal because the ratio of the heat transfer surface area to the reactor volume is reduced. Identical conditions for heat transfer in both the model and full-scale plants may be achieved in exothermal reactions if both have the same thermal stability coefficient. This requirement is obtained by introducing external heat exchangers. Alternatively, a reactor with a strong exothermic reaction can be divided into several small size reactors. In this manner, the ratio of the external heat transfer surface area to the reactor volume is increased, thereby avoiding an excessive temperature rise in the reactor. 

It is possible to capture the trends in OER activities observed in experiments with the simple analysis discussed previously. The hypothesis is that the main difference in activity between two catalysts is related to the difference in the potential needed to drive the most difficult reaction step. The main assumption is that barriers along the reaction scale with the reaction free energies see also the original literature [13, 17,21],... 

The conditions under which CO gas bubbles form and the reaction scale fractures depend on the relative permeabilities of CO and oxygen through the reaction scale, which typically consists of a three-phase mixture of mullite, alumina, and an aluminosilicate glass. If the CO permeability is greater than... 

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