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Search for "scale-up" in Full Text gives 199 result(s) in Beilstein Journal of Organic Chemistry.
Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant
Beilstein J. Org. Chem. 2016, 12, 1598–1607, doi:10.3762/bjoc.12.156
- characteristic NOESY signal encircled. Substrates that gave no products in flow. Comparison of early C–N and C–O coupling reactions. Scope of the catalytic Chan–Lam reaction in continuous flow. Syntheses of substrate 39. Scale-up procedure for 19. Optimisation of the Chan–Lam reaction in continuous flow
Flow carbonylation of sterically hindered ortho-substituted iodoarenes
Beilstein J. Org. Chem. 2016, 12, 1503–1511, doi:10.3762/bjoc.12.147
- smaller when larger volume flasks are used as in scale up procedures making the mass transfer even less efficient. In contrast, high interfacial areas can be achieved in flow reactors especially microchannel reactors (a = 3400–18000 m2 m−3) [30], which increases the mass transfer and thus helps solubilise
- turnaround time is much longer. This makes the flow reactor more efficient in terms of processing time. Additionally, the added safety and potential benefits regarding scale up associated with the flow reactor makes this even more favourable. Having identified a set of reaction conditions for successful
- of ortho-substituted substrates giving moderate to good yields. Comparison of 22 with 32 also showed that the steric encumbrance on the ortho position has an effect on the yield even when other electronic effects are in place such as those coming from the additional aromatic ring attached. A scale-up
Asymmetric α-amination of 3-substituted oxindoles using chiral bifunctional phosphine catalysts
Beilstein J. Org. Chem. 2016, 12, 725–731, doi:10.3762/bjoc.12.72
- -substituent was changed to an alkyl group (Table 3, entry 18). Subsequently, a scale-up experiment on 1.0 mmol scale of the reaction was examined, and the corresponding product could be obtained smoothly with a slightly reduced yield (70%) and ee (85%). The ee value of the product could be raised to 96% after
- spectra research in CD2Cl2. The mimetic activation mode of Mitsunobu reaction. Scale-up of the reaction and deprotection of the product. Proposed transition-state model. Catalyst screening. Optimization of conditions. Substrate scope. Supporting Information Supporting Information File 32: Experimental
Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography
Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68
- technique for the investigation of polar extracts. Moreover, the commercial availability of industrial instruments enables scale-up to batch production for high-scale isolation. The CPC technique turned to be a versatile analytical tool leading to the purification and identification of new glycosylated
New synthetic strategies for xanthene-dye-appended cyclodextrins
Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53
- dyes and coupling agents, thus having clear potential for multigram scale-up. The mild, aqueous conditions, as well as the simplicity of the synthesis, make these reactions attractive tools for the preparation of fluorescent cyclodextrins connected through an amide bond. The obtained products were
Enabling technologies and green processes in cyclodextrin chemistry
Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30
- technology can exploit a liquid milling medium. The preparation of CD and other complexes with the aid of ball milling is well-known [82][83]. In spite of an easy scale-up of this technology, some disadvantages might occur: metastable crystalline complexes can recrystallize to an equilibrium state upon
A quadruple cascade protocol for the one-pot synthesis of fully-substituted hexahydroisoindolinones from simple substrates
Beilstein J. Org. Chem. 2016, 12, 253–259, doi:10.3762/bjoc.12.27
- [65]. However, substrates with aliphatic R1, R2 or R3 did not produce the desired products (Table 2, entries 21–26). This bifunctional catalysis cascade reaction was also amenable to scale-up. When the reaction was carried out on a 3 mmol scale, the desired product was obtained in 84% yield. Therefore
Catalytic asymmetric formal synthesis of beraprost
Beilstein J. Org. Chem. 2015, 11, 2654–2660, doi:10.3762/bjoc.11.285
- improved to 85% ee while maintaining the high reactivity. Employing catalyst E we further investigated the reaction conditions and found that a scale-up synthesis can be performed using only 1 mol % of E with no loss of enantioselectivity, although gentle heating was required to ensure a high chemical
- exchange and subsequent addition to methyl 4-oxobutanoate was found to be the best method to introduce the C4 subunit with reproducibility in the case of scale-up synthesis. Deprotection of the resultant ester 23 followed by reduction of the benzylic OH group finally afforded the key intermediate 2
Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors
Beilstein J. Org. Chem. 2015, 11, 2408–2417, doi:10.3762/bjoc.11.262
- phase separation into alternating organic–aqueous segmented flow; whilst meso-scale reactors are much better suited, and provide more accurate and reliable information for scale-up. Interaction of the reactants occurs only at the phase interface, so efficient mixing increases the surface area and
Efficient synthetic protocols for the preparation of common N-heterocyclic carbene precursors
Beilstein J. Org. Chem. 2015, 11, 2318–2325, doi:10.3762/bjoc.11.252
- solvent and hinders scale up. Synthesis of 1,3-bis(2,6-diisopropylphenyl)imidazolinium chloride In most cases, experimental procedures leading to 1,3-dimesitylimidazolinium salts could be successfully extended to their 1,3-bis(2,6-diisopropylphenyl) counterparts without any adaptation. Thus, the three
- laboratories and do not require any particular skills from the experimenter. Furthermore, the detailed experimental procedures supplied in Supporting Information File 1 of this article are easy to scale up or down according to the particular needs for a given compound. Thus, we hope that they will be helpful
Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyl)oxazoles
Beilstein J. Org. Chem. 2015, 11, 2021–2028, doi:10.3762/bjoc.11.219
- /ethyl acetate mixture (7:3) as the eluent. After the reaction was cooled to room temperature ice-cold water was added. The precipitate obtained was filtered, dried in vacuum and recrystallized from ethanol to afford 3. Representative scale-up example for the synthesis of 3e using the 80 mL vessel: In an
- completion of the reaction, the mass was treated with ice cold saturated solution of sodium bicarbonate and extracted with ethyl acetate (2 × 10 mL). The combined organic layers were dried with anhydrous Na2SO4 and concentrated in vacuo to afford oxazole 8. Representative scale-up example for the synthesis
Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers
Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174
- traditional polymerization methods [52]. Binns et al. summarized the attempts to scale up synthesis of polyesters by enzyme catalyzed polycondensation of adipic acid and hexane-1,6-diol in a very well-worth reading article [53]. They discussed the very slow progress in achieving high molecular weight polymers
The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry
Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134
- scale-up campaign were found to be related to safety, isolated purity and economics. The successful outcome of the above study can in part be ascribed to the use of a static mixing device which allowed for the selective and clean mono-deprotonation under scale-up conditions. This was in stark contrast
- chemistry is an increase in reproducibility this seems a rather negative trend. In 2012 researchers from AstraZeneca (Sweden) reported upon a scale-up campaign for their gastroesophageal reflux inhibitor programme. Specifically, flow chemical synthesis was used to efficiently and reliably provide sufficient
- worked well. As seen above, avoiding detrimental exotherms in scale up campaigns is a common reason for developing a continuous flow process. This approach is also demonstrated in the synthesis of the pyrrolotriazinone 73 via a exothermic oxidative rearrangement from 75, a key intermediate towards
Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes
Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125
- sodium borohydride and lithium bromide to 40 g scale, obtaining diol 11 with only a small reduction in yield (77% vs 85% at 15 g scale [33]). Compound 11 is then treated with phosphorus tribromide to afford dibromide 12. The scale up of this reaction to 36 g scale also results in a lower, but still
Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3
Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282
- perform more biological assays for this unusual norditerpenoid, further scale-up isolation is in progress. Experimental General experimental procedures The melting point was measured on a Beijing Taike X-5 stage apparatus and reported without correction. The optical rotation was recorded using a Rudolph
Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids
Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260
- ]. Besides carbonyl compounds, imines have also shown value as substrates for electrocarboxylation, namely in the synthesis of non-natural amino acids [102][103][104][105][106][107][108]. A semi-industrial setup was designed for the electrocarboxylation of benzalaniline (Scheme 14). Scale up was done in a
Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments
Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247
- approaches are improved safety characteristics, enhanced rates of heat and mass transfer, simplicity and robustness in scale-up and easiness in handling the instrumentation [30][31][32][33]. For the synthesis of compound 7, two distinct solutions containing the hemiacetal 6 in pyridine and
Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing
Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219
- ) the formation of 10 was very sensitive to the reaction conditions and thus typically gave low yields (approx. 10%) upon scale-up; (2) the reaction must be run in very dilute solution to minimize the formation of larger cyclooligomers as well as polymer; (3) pure 10 in the solid state is reported to be
Synthesis of rigid p-terphenyl-linked carbohydrate mimetics
Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182
- conditions providing diol 8 in excellent yield in multigram scale (up to 20 g). Attention should be paid to a possible reductive removal of the bromine substituent that can occur at higher temperature or longer reaction times as the resulting debrominated product is hard to remove from diol 8 by column
The chemoenzymatic synthesis of clofarabine and related 2′-deoxyfluoroarabinosyl nucleosides: the electronic and stereochemical factors determining substrate recognition by E. coli nucleoside phosphorylases
Beilstein J. Org. Chem. 2014, 10, 1657–1669, doi:10.3762/bjoc.10.173
- to a high stability of the α-phosphate 12a under the studied reaction conditions. On the other hand, the extremely poor solubility of 2-chloroadenine in water (ca. 70 mg in 1.0 L at 50 °C) did not allow to scale up the synthesis, and based on an experiment on a milligram scale clofarabine was
Nonanebis(peroxoic acid): a stable peracid for oxidative bromination of aminoanthracene-9,10-dione
Beilstein J. Org. Chem. 2014, 10, 921–928, doi:10.3762/bjoc.10.90
- with hexane/ethyl acetate (95:5) as an eluent to give purified product 2. Scale-up study The reaction of 1-aminoanthracene-9,10-dione with KBr in acetic acid and nonanebis(peroxoic acid) as an oxidant was scaled-up to 10 g to understand the functioning of the method on a larger scale. The reaction
Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide
Beilstein J. Org. Chem. 2014, 10, 641–652, doi:10.3762/bjoc.10.56
- material wasted during start up and shutdown of the first step can be reduced. We anticipate that the potential to rapidly realise complex control sequences such as these will further broaden the scope for the use of flow chemistry reactors in both the research and scale-up environments. We hope that the
Preparation of new alkyne-modified ansamitocins by mutasynthesis
Beilstein J. Org. Chem. 2014, 10, 535–543, doi:10.3762/bjoc.10.49
- and MS experiments clearly showed common patterns for ansamitocins. Additionally, the isotopic pattern provided evidence for the incorporation of the bromo functionality (see Supporting Information File 1). However, yields for each of the four ansamitocins were too small for practical scale-up. To
- patterns and isotopic composition in the MS. Bromo-ansamitocin derivatives 22a, 22c and 22e were isolated after scale up to a 1000 mL culture broth. Structures, expected from HRMS analysis, were corroborated by NMR spectroscopy. Yields were determined to be in the low mg/L range or 0.01% yield based on
Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers
Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47
- limited by scale up issues. However, several features of the currently described SET promoted excited state reactions make them suitable for applications in unique situations, especially when the processes require a high degree of temporal and spatial control. α-Heterolytic cleavage in ion radicals
Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)amino]acetyl}amino)benzophenone; a case of configurationally stable stereogenic nitrogen
Beilstein J. Org. Chem. 2014, 10, 442–448, doi:10.3762/bjoc.10.41
- commercial application of chiral complex 1 is rather limited. The major shortcomings of compound 1 are: problematic scale up of its synthesis, partial racemization of the N-(benzyl)proline moiety and undesirable stereochemical outcomes. To overcome these deficiencies we initiated a project aiming to design a
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