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Search for "crystallization" in Full Text gives 302 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Selectivity control towards CO versus H2 for photo-driven CO2 reduction with a novel Co(II) catalyst

  • Lisa-Lou Gracia,
  • Philip Henkel,
  • Olaf Fuhr and
  • Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

Graphical Abstract
  • ). Efforts to selectively achieve one polymorph, through differentiated crystallization processes, were unsuccessful. When analyzing the molecular structure in both crystals, the cobalt core is hexacoordinated, as expected. The two isothiocyanate ions are oriented cis to each other and trans to the
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Published 17 Nov 2023

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

  • Alessandro L. Alves,
  • Simone V. Bernardino,
  • Carlos H. Stadtlober,
  • Edivandro Girotto,
  • Giliandro Farias,
  • Rodney M. do Nascimento,
  • Sergio F. Curcio,
  • Thiago Cazati,
  • Marta E. R. Dotto,
  • Juliana Eccher,
  • Leonardo N. Furini,
  • Hugo Gallardo,
  • Harald Bock and
  • Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

Graphical Abstract
  • 1758 cm−1 (C=O). X-ray diffraction (XRD) measurements of 1 and 2 are shown in Figure 2. The Miller indices indicate the Colhex and Colrect character of the mesophases [31]. Despite crystallization of 2, the Colrect order is partially preserved at room temperature. The Colhex lattice parameter (a
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Published 16 Nov 2023

Unprecedented synthesis of a 14-membered hexaazamacrocycle

  • Anastasia A. Fesenko and
  • Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

Graphical Abstract
  • with a noticeable increase in the macrocycle yield up to 41% (Table 1, entries 20 and 21). The extremely poor solubility of product 5 in most organic solvents allowed to purify it from all admixtures, including byproduct 6, by a single crystallization from boiling DMF. Thus, pure product 5 was prepared
  • noteworthy that triazole 10 was the major product in dioxane (10/5/6 = 86.5:13:0.5, Table 1, entry 23). Again, macrocycle 5 was separated from this mixture by crystallization from DMF, and pyrazolyl-1,2,4-triazole 10 was isolated from the mother liquor. The structure of compound 10 was established based on
  • , 3 h) followed by crystallization of the crude product from DMF. The use of compound 8 as a starting material affords the target product 5 with higher purity and yield compared with the use of imidate 4. Moreover, pyrazolopyrimidine 8 itself is much more stable than imidate 4, and its intermediate
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Published 15 Nov 2023

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

  • Dayanne Martins,
  • Roberta Lamosa,
  • Talis Uelisson da Silva,
  • Carolina B. P. Ligiero,
  • Sérgio de Paula Machado,
  • Daphne S. Cukierman and
  • Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

Graphical Abstract
  • beige and light-yellow solids with 78% and 44% yield, respectively. Thermal analyses between 25 and 350 °C were performed in order to verify the hydration status of the bulk. Regarding hdz-CH3, a weight loss of 9.78% from around 80 to 190 °C was observed, suggesting the presence of two crystallization
  • the structures (Figure 2A) shows that spatial arrangements are nearly the same and even the crystallization water molecules were allocated in nearby sites, interacting as H-acceptors in a hydrogen bond with the respective N2H groups. In spite of these similarities, the compounds were indexed in
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Published 10 Nov 2023

CO2 complexation with cyclodextrins

  • Cecilie Høgfeldt Jessen,
  • Jesper Bendix,
  • Theis Brock Nannestad,
  • Heloisa Bordallo,
  • Martin Jæger Pedersen,
  • Christian Marcus Pedersen and
  • Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

Graphical Abstract
  • yields was sufficient time for the crystallization, while the pressure was found less important. From the binding constant measured below and the 1:1 stoichiometry (Kg = 0.18 bar−1, Table 2) we know that 1/2 to 3/4 of the cyclodextrin is filled with CO2 at the pressures used as shown in the 5th column of
  • Table 1. As CO2 is in large excess high crystal yields can be obtained even though the CD cavity is only partially filled, because more CO2 is bound in solution as crystallization proceeds. When equilibrium is reached as in entries 1–3 (Table 1) the concentration of 1·CO2 is 0.04 M which must be the
  • lipophilic cyclodextrin derivative. It suggests that stronger CO2 binders can be found by improving on these two traits. Experimental Crystallization experiments. A cyclodextrin solution was prepared by dissolving 1 in Milli-Q water to the indicated concentration (Table 1) . The solution was then filtered
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Published 17 Jul 2023

First synthesis of acylated nitrocyclopropanes

  • Kento Iwai,
  • Rikiya Kamidate,
  • Khimiya Wada,
  • Haruyasu Asahara and
  • Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

Graphical Abstract
  • the same way, and the obtained product 9 was converted to the 2,4-dinitrophenylhydrazone 10 to facilitate the crystallization for X-ray crystallography, which showed that a 2,3-dihydrofuran framework had formed (Scheme 4, bottom). Hence, we clarified that product 8b was not the desired cyclopropane
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Published 21 Jun 2023

Light-responsive rotaxane-based materials: inducing motion in the solid state

  • Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

Graphical Abstract
  • Photoresponsive rotaxane discrete crystals A complete understanding of the crystallization mechanisms accompanied by a rational design can lead to the obtention of crystalline molecular materials which allow the dynamics of the counterparts to take place [35][36][37]. Indeed, the motion of the cyclic counterparts
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Perspective
Published 14 Jun 2023

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

  • Ekaterina A. Lystsova,
  • Maksim V. Dmitriev,
  • Andrey N. Maslivets and
  • Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

Graphical Abstract
  • reaction of APBTT 1a with benzylamine (Scheme 11). As we expected, this reaction proceeded similarly to the reaction of APBTTs 1 with alcohols 2, and we obtained the desired PBTA 7a in a good isolated yield (44%). The product 7a was isolated by simple crystallization from the reaction mixture. Next, the
  • (11a, Scheme 16). This reaction proceeded similarly to reactions of APBTTs 1 with alcohols 2 and benzylamine, and we obtained the desired PBTA 12aa in a moderate isolated yield (40%). The product 12aa was isolated by simple crystallization from the reaction mixture. Next, the conditions (Table 3) of
  • isolated by a simple crystallization from the reaction mixture. Moreover, we observed the formation of compounds 17 during acylation of enamines 15 with oxalyl chloride to prepare the starting APBTTs 1 (Scheme 21). We noticed that in this case, compounds 17 were formed when HCl was not effectively removed
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Published 11 May 2023

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

  • Jorge de Lima Neto and
  • Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

Graphical Abstract
  • -methylcorniculatolide A (5, 10 mg), 12-hydroxy-11-O-methylcorniculatolide A (6, 1 mg) and 11-O-methylisocorniculatolide A (8, 2 mg). The authors had some difficulties to isolate isocorniculatolide A (5) using chromatography, however, it was obtained by crystallization from hexane and acetone (4 mg). The same strategy
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Published 29 Mar 2023

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

  • Nicoleta G. Hădărugă,
  • Gabriela Popescu,
  • Dina Gligor (Pane),
  • Cristina L. Mitroi,
  • Sorin M. Stanciu and
  • Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

Graphical Abstract
  • -crystallization [10]. Omega-3 FA glycerides such as eicosapentaenoic and docosahexaenoic acid glycerides (EPA and DHA glycerides) from fish oil are less stable against oxidation. Their thermal and oxidative stabilities were significantly increased by CD nanoencapsulation as was shown for fish oil from common
  • kneading method as the most appropriate one for obtaining β-CD/hazelnut (Corylus avellana L.) oil/flavonoid glycoside or flavonolignan ternary complexes. Kneading allows for higher recovery yields of complexes in comparison with the co-crystallization method because only small amounts of solvent are needed
  • (common barbel, Pontic shad, European wels catfish, common bleak) by CDs [11][17]. Moreover, this TG behavior does not depend on the method of synthesis (kneading or co-crystallization) or the method of water determination (TG as mass loss or Karl Fischer water titration, KFT) [6][68]. It was observed
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Published 28 Mar 2023

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

  • János Máté Orosz,
  • Dóra Ujj,
  • Petr Kasal,
  • Gábor Benkovics and
  • Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

Graphical Abstract
  • most cases, the preparation of these compounds is based on the use of a limited amount of the reagent. However, due to the very similar reactivity of hydroxy groups, oversubstitution cannot be avoided during the reaction, thus chromatography or crystallization steps are essential for the preparation of
  • -CD (2), overreacted byproducts, and starting β-CD (1). However, in previous studies this has been reported as a clean product with a yield of almost 50% [31][33]. Recrystallization is mandatory to obtain pure Ts-β-CD (2) [38][39]. The best results are obtained by crystallization of the crude product
  • monosubsituted compound was performed after this last modification. After precipitation, an apparent yield of more than 90% was noted; however, this value did not take into account native β-CD (1) as byproduct. On the other hand, if purification by column chromatography or crystallization is also used, yields of
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Published 09 Mar 2023

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr4/PPh3 and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

  • Christian Schumacher,
  • Jas S. Ward,
  • Kari Rissanen,
  • Carsten Bolm and
  • Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

Graphical Abstract
  • flash chromatography (petroleum ether) to afford compound 5 (2.47 g, 63%) as faint creamy sticks upon crystallization from Et2O. Rf = 0.26 (petroleum ether); mp: 98 °C [10] (reported mp: 114−115 °C [18]; IR: ν 2081 (N3 str) cm−1; 1H NMR (600 MHz, CDCl3) δ 5.39 (t, J = 2.3, 4.8 Hz, 1H, H-6), 3.87 (t, J
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Published 27 Jan 2023

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

  • Alexios I. Vicatos,
  • Zakiena Hoossen and
  • Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

Graphical Abstract
  • to prepare complexes by spray-drying, freeze-drying, co-grinding, kneading and solution-based crystallization; however, this modest type of ‘fingerprinting’ has not generally been pursued further to deduce important features of CD complexes such as the crystal packing of the CD host molecules
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Published 22 Dec 2022

Inline purification in continuous flow synthesis – opportunities and challenges

  • Jorge García-Lacuna and
  • Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

Graphical Abstract
  • exploited to achieve effective and reliable flow processes. This perspective article summarizes recent applications of different inline purification techniques such as chromatography, extractions, and crystallization from academic and industrial laboratories. A discussion of the advantages and drawbacks of
  • stationary phases is simulated by periodically shifting the two inlet and outlet ports in the direction of the mobile phase flow after a certain time. This technique was also applied to isolate artemisinin from a continuously produced reaction mixture. However, an offline crystallization had to be added to
  • , this strategy is attractive for rapid small-scale syntheses of such scaffolds and the optimization of the used solvents can broaden the uptake of this strategy. Inline precipitation and crystallization One of the most widely acknowledged challenges within the field of flow chemistry is the necessity to
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Published 16 Dec 2022

Design, synthesis, and evaluation of chiral thiophosphorus acids as organocatalysts

  • Karen R. Winters and
  • Jean-Luc Montchamp

Beilstein J. Org. Chem. 2022, 18, 1471–1478, doi:10.3762/bjoc.18.154

Graphical Abstract
  • intermediates 13a and 13b, respectively. Next, conversion of ethyl phosphinate 13 into phosphinamide 14 was accomplished uneventfully [38] with inexpensive (S)-1-phenylethylamine (15 $/mol) as the chiral element. A single diastereoisomer of phosphinamide 14b was easily obtained by crystallization in 20% yield
  • obtained in moderate yield. Crystallization gave a single diastereoisomer in 20% yield. Stec reaction [38][39][40] finally gave the desired CPA 4. Although the entire sequence proceeded in only 6% overall yield, it was conducted on a multigram-scale so that more than 0.4 g of 4 was obtained. Evaluation of
  • accomplished easily, either by chromatography over silica gel or crystallization. Subsequent Stec reaction proved to be a reliable method to convert the resolved amide into the chiral thiophosphorus acids. The CPAs synthesized clearly failed to induce any significant asymmetry. It is interesting to note
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Published 17 Oct 2022

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

  • Péter Kisszékelyi,
  • Tibor Peňaška,
  • Klára Stankovianska,
  • Mária Mečiarová and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

Graphical Abstract
  • decomposed in solution. During the preparation of 10ac, dimers 11a and 11b were also detected in most experiments (TLC analysis), and they could be isolated by crystallization from MeOH or hexane. Performing the reaction in the dark with freshly degassed ethanol at lower temperature did bring about somewhat
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Published 09 Sep 2022

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

  • Dmitry Dar’in,
  • Grigory Kantin,
  • Alexander Bunev and
  • Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

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  • anticancer cytotoxic agents. Diverse bioactive compounds based on the privileged 1,4-DHIQ scaffold. Strategy investigated in this work. Preparation of 3(2H)-isoquinolones 11. aObtained as a 10:1 mixture of regioisomers; purified by crystallization. bEmployed in the next step without purification (not
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Published 22 Aug 2022

On Reuben G. Jones synthesis of 2-hydroxypyrazines

  • Pierre Legrand and
  • Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

Graphical Abstract
  • set up to run chromatography at 60 °C, a description of the crystallization, data collection, for the structural determination of compound 4{1,2} as well as copies of the 1H and 13C NMR spectra of all compounds described. Acknowledgements We thank Dr. Ahmed Haouz of the PF6 core facility of the
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Published 29 Jul 2022

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

  • Conrad Kuhwald,
  • Sibel Türkhan and
  • Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

Graphical Abstract
  • was then mixed with a 1 M HCl solution in iPrOH that initiated crystallization of the hydrochloride salt of amitryptiline (84) (Scheme 15). Iso E Super® (88) [89] is one of the most successful synthetic fragrances ever developed [90]. It is a component of a variety of perfumes with varying ratios and
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Published 20 Jun 2022

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

  • Martin Vrbický,
  • Karel Macek,
  • Jaroslav Pochobradský,
  • Jan Svoboda,
  • Miloš Sedlák and
  • Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

Graphical Abstract
  • /waxy solid material, what made the attempts of recrystallization impossible. On the other hand, the corresponding amides 27 and 28 were obtained as fine crystalline solids. Their crystallization was successfully performed from several solvents. However, the de values of the isolated recrystallized
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Published 14 Apr 2022

Trichloroacetic acid fueled practical amine purifications

  • Aleena Thomas,
  • Baptiste Gasch,
  • Enzo Olivieri and
  • Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

Graphical Abstract
  • this mixture dissolved in EtOAc, precipitation of the amine salt enabled the removal of naphthalene in the solvent. Beside the choice of the solvent for the crystallization which strongly depends on the solubility of the protonated amine salts involved, we first focused on the optimization of the
  • isolated in its pure form starting from model mixtures containing various aromatics, phenols, alkanes or alkenes in overall purification yields ranging from 53 to 98%. The lower yields are observed for coordinating phenol and catechol (Table 2, entries 3 and 4), probably impacting the crystallization
  • importance, this technique is also efficient for the isolation of highly complex natural amines such as brucin, isolated in 57% yield using TCA (Table 3, entry 14). As mentioned, identification of a suitable solvent solubilizing the initial mixture and enabling precipitation/crystallization of the amine salt
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Published 24 Feb 2022

Stepwise PEG synthesis featuring deprotection and coupling in one pot

  • Logan Mikesell,
  • Dhananjani N. A. M. Eriyagama,
  • Yipeng Yin,
  • Bao-Yuan Lu and
  • Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

Graphical Abstract
  • reaction, which mainly include styrene and p-toluenesulfonic acid. As a result, when the reaction is performed at large scales, there is a high probability that the product can be purified by methods such as partition, precipitation and crystallization. The major advantage of using a base-labile protecting
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Published 28 Dec 2021

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

  • Ettore Crovini,
  • Zhen Zhang,
  • Yu Kusakabe,
  • Yongxia Ren,
  • Yoshimasa Wada,
  • Bilal A. Naqvi,
  • Prakhar Sahay,
  • Tomas Matulaitis,
  • Stefan Diesing,
  • Ifor D. W. Samuel,
  • Wolfgang Brütting,
  • Katsuaki Suzuki,
  • Hironori Kaji,
  • Stefan Bräse and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

Graphical Abstract
  • with a low-Tg host like CBP, which is prone to crystallization, the obtained emitter orientation even turned vertical with the a factor approaching 0.40 [39]. Thus, measurements of the anisotropy factor were accordingly carried out for both ICzTRZ and DICzTRZ. Polarization and angle dependent
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Published 08 Dec 2021

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

  • Lukáš Ďurina,
  • Anna Ďurinová,
  • František Trejtnar,
  • Ľuboš Janotka,
  • Lucia Messingerová,
  • Jana Doháňošová,
  • Ján Moncol and
  • Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

Graphical Abstract
  • -catalyzed hydrolysis of 10 with concentrated hydrochloric acid in acetone/water afforded diol 3 in excellent 93% yield. The crystallization of the crude product from a hexanes/CH2Cl2 mixture led to the preferential formation of the thermodynamically more stable 4,5-cis isomer (determined on the basis of a
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Published 24 Nov 2021

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

  • Umesh P. Aher,
  • Dhananjai Srivastava,
  • Girij P. Singh and
  • Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

Graphical Abstract
  • highly effective crystallization-induced DKR to achieve an efficient synthesis of enantiomerically pure oxathiolane-based lactol 56a from ʟ-menthyl glyoxylate (3h) monohydrate and 1,4-dithiane-2,5-diol (3q, Scheme 17). The investigation proved that the base TEA was capable of effecting the equilibration
  • at C-2 but advantageous for the crystallization process. A number of bases was also evaluated by this research group: pyridine gave only a small amount of interconversion, whereas TEA caused rapid interconversion. Furthermore, it was discovered that instant interconversion and crystallization of 56a
  • (1), as summarized in the next section. Access to crystalline 5-acetoxyoxathiolane 35a was accomplished either by selective crystallization in the presence of the remaining diastereoisomers, although in only 16% yield, or by a classical resolution method using the norephedrine salt 58 (Scheme 19
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Published 04 Nov 2021
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