Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• substrate and allowed to dry at room temperature. To improve the conductivity and achieve higher resolution SEM imaging, a 20 nm thick layer of Au was sputtered onto the sample surface. For EDS mapping, the samples were not sputtered with Au to avoid interference during the determination of Pt. UV–vis

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• phenolate zwitterions at room temperature. Nine different zwitterions were synthesized and fully characterized. Zwitterions with the poor Michael acceptors methyl methacrylate and methyl crotonate formed, but could not be isolated in pure form. The solid-state structures of two phosphonium phenolate

• toward the desired product 3-(allyloxy)propanenitrile was observed after stirring the reaction mixture for 24 h at room temperature. Analyzing the reaction mixture with 1H NMR spectroscopy revealed the formation of a minor amount of a novel compound characterized by two multiplets centered at 3.31 and

• with allyl alcohol (in both cases using a molar ratio of 1:1.05 and dichloromethane as the solvent). While in the latter case only the starting materials were observed after 24 h at room temperature, the reaction of 1 with acrylonitrile turned yellow during the same time and exclusively yielded the

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• groups. Aromatic micelle (PA-CH3)n was furthermore found to be stable for at least six days at room temperature in the dark (see Figure S37 in Supporting Information File 1). Noncovalent encircling of various nanocarbons in water By employing a simple grinding–sonication protocol, various nanocarbons

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• -carbonitrile (4) in 5% yield when the reaction was carried out at room temperature in 1,4-dioxane in the presence of an equivalent amount of TEA (Table 1, entry 1). This result is in contrast to our previous findings where the reaction of compound 1a with sulfonyl azides led to 5-amino-1,2,3-triazole-4-N

• -sulfonylamidines selectively [17]. The following screening of organic (Table 1, entries 2‒7 and 8) and inorganic (Table 1, entry 10) bases at room temperature revealed that using DBU resulted in the highest yield of triazole 3a. Analysis of experiments with 100 mol %, 120 mol %, and 80 mol % of DBU (Table 1

• triazoles 3 Method A. In a manner similar to [17], DBU (0.5 mmol) was added to the solution of amidine 1 (0.5 mmol) in 1,4-dioxane (2 mL) at room temperature and azide 2 (0.5 mmol) was added to the resulting solution 5 min later. The reaction mixture was stirred for 30 min at room temperature, then water (6

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• with alternative solvents could represent an important innovation for alkyne hydration. In particular, ionic liquids (ILs) could represent a valid alternative to conventional organic solvents. ILs are generally liquid salts at or near room temperature, formed by large unsymmetrical organic cations and

• this way, the hydration product was not obtained. In addition to the different reactivity, due to the presence or not of chlorine in the para position of the phenyl group, the different physical state (liquid for 1m vs solid for 1n) and the possible different solubility in BMIm-BF4 at room temperature

• anolyte and the mixture was kept under stirring at room temperature for 30 min. Then, the neat anolyte was analysed by NMR (19F and 13C). The 19F NMR spectrum showed a new peak at −148.7 ppm and, to our great astonishment, we found only one set of signals in the 13C NMR spectrum (55.0, 42.8, 17.4, 16.0

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• report described the preparation of a CAAC·CS2 zwitterion. Thus, in 2009 Bertrand et al. obtained the betaine 2 by reacting the free carbene 1 with a slight excess of CS2 in THF at room temperature (Scheme 1) [62]. The starting material that featured a bulky and rigid spirocyclic alkyl group derived from

• required the use of a double amount of base. The suspensions were brought back to room temperature and allowed to settle down to ease the filtration of the inorganic byproducts (KCl or KBF4), along with any unreacted starting materials. Adding an excess of CS2 to the free carbene solutions led to the

• equiv) in THF at 0 °C. The potassium iodide byproduct was filtered off and carbon disulfide (3.3 equiv) was added to the carbene solution leading to an immediate color change. After 30 min at room temperature, the solvent was evaporated under vacuum. The residue was washed with petroleum ether and dried

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• , α-halogenated p-toluenesulfonylhydrazones 6 were also used in the reaction and the results are summarized in Scheme 4. As it can be seen, the triethylamine-mediated [4 + 3] cycloaddition could be accomplished at room temperature in two hours. These results clearly showed that the α-halogenated p

• [indoline-3,5'-[1,2]diazepines] 3a–l: A 10 mL reaction tube was charged with α-halogenated acylhydrazone (0.2 mmol), MBH nitrile of isatin (0.1 mmol), triethylamine (0.2 mmol) and dichloromethane (4.0 mL) and the mixture was stirred at room temperature for 24 hours. After removing the solvent by rotatory

• dihydrospiro[indoline-3,5'-[1,2]diazepines] 5a–i: A 10 mL reaction tube was charged with α-halogenated acylhydrazone (0.2 mmol), MBH ester of isatin (0.1 mmol), DABCO (0.2 mmol, 0.0224 g), and dichloromethane (4.0 mL) and the mixture was stirred at room temperature for 24 hours. After removing the solvent by

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• experiments were carried out in a controlled environment with 0.1 M tetrabutylammonium hexafluorophosphate as the electrolyte and anhydrous dichloromethane as the solvent, maintaining room temperature conditions under a nitrogen atmosphere. To ensure accurate potential measurements, the system utilized silver

• duration 6 ns. b) Electric field dependence of electron mobility for the layer of 7 at room temperature (295 K). Synthesis of dicyanocarbazole 6. Reaction conditions: a) cyanoacetamide, piperidine, methanol, 40 °C, 48 h; b) POBr3, 170 °C, 1 h; c) 3,6-di(tert-butyl)carbazole, NaH, THF, DMF, 0 → rt, 3 h; d

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• radicals [10][11], which react even at room temperature. However, the one-electron reduction of La@C2v-C82 is effective for the activating its reactivity toward alkyl halides in the thermal reaction. Recently, Zhou et al. reported that the reaction of Gd@C2v-C82 with benzyl bromide requires a three

• -electron reduction of Gd@C2v-C82 for the addition reaction to occur at room temperature [22]. Supporting Information File 1, Figure S1 depicts the three HPLC separation steps including recycling for the isolation. The matrix-assisted laser desorption/ionization time-of-flight (MALDI–TOF) mass spectra of 2a

• , assuming that La@C2v-C82 and the monoadducts have the same absorption coefficients. X-ray crystallography Black crystalline rods of 3a were obtained using the liquid–liquid bilayer diffusion method with 3a in a CS2 solution and an n-hexane solution in a glass tube (⌀ = 7 mm) at room temperature. The SC-XRD

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• , dimesitylborofluoride (130 mg, 0.490 mmol) was added rapidly. The mixture was further stirred at −78 °C for 1 h, then, allowed to warm to room temperature and stirring was continued overnight. The solution was extracted with dichloromethane, and the organic layer was washed with Na2CO3 solution (10%) and water. The

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• procedures [35][37]. Synthesis of porphyrin compounds 3a–h,j,k and 4b–g,j N-Tosylimine 2 (0.090 mmol) and Cu(OTf)2 (0.0090 mmol) were dissolved in CH2Cl2 (0.5 mL) and stirred at room temperature for 30 minutes under N2 atmosphere. To this mixture was added a solution of 5,10-bis(pentafluorophenyl

• compounds 6a–f and 7d N-Tosylimine 2 (0.097 mmol) and Cu(OTf)2 (0.0097 mmol) were dissolved in CH2Cl2 (0.5 mL) and stirred at room temperature for 30 min under N2 atmosphere. To this mixture was then added a solution of 5,10-bis(4-trifluoromethylphenyl)tripyrromethane (5, 0.097 mmol) in CH2Cl2 (1.5 mL) and

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• , trifluoroacetic acid (5.74 mL, 75 mmol, 63 equiv) was added dropwise. The reaction mixture was stirred at room temperature for 1 h. Then, it was cooled to 0 °C, and a 40% NaOH(aq) solution was added to set the pH to 13. To this mixture, water (60 mL) was added, and it was extracted with DCM/MeOH 20:1 (60 mL

• lipophilic organocatalyst 2 (6.3 mg, 0.004 mmol, 5 mol %) were dissolved in the appropriate solvent (500 µL). Then, acetylacetone (13, 21.1 μL, 0.205 mmol) was added. The reaction mixture was stirred for 24 hours at room temperature. After the reaction was completed, the solvent was evaporated, and the crude

• . The reaction mixture was stirred for 24 hours at room temperature. Then, the volatile components were evaporated, and acetonitrile (2 mL) was added. The dissolution of the product and the suspension of the catalyst were aided by using an ultrasonic bath. The reaction mixture was transferred to

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• light irradiation at either 440 nm or 456 nm, and they occurred in acetone at room temperature, without the need for transition metals or organic dyes as photosensitizers. Interestingly, it was discovered that solvation played a vital role in the overall process. These findings shed light on the

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• macrocycles are more shifted, with the triazole proton presenting an upfield shift from δ = 7.95 ppm to δ = 7.65 ppm and the hydroquinone protons are upfield shifted from δ = 6.77/6.67 ppm to δ = 6.60/6.58 ppm. In order to validate formation of R1 we also recorded a room-temperature H,H-ROESY NMR spectrum

• 50% (2.25 g, 56.28 mmol, 26.4 equiv) was added dropwise, followed by TBAB (0.17 g, 0.53 mmol, 0.25 equiv). 2,6-Bis(bromomethyl)pyridine (0.56 g, 2.11 mmol, 1 equiv) was added after 30 minutes and the mixture was stirred for 2 days at room temperature. After solvent evaporation, water (50 mL) was

• ). CuCl(SIMes)(4,7-dichlorophenantroline) (39 mg, 0.06 mmol, 0.1 equiv) was added and the mixture was stirred for 4 days at room temperature. The solvent was evaporated and the residue was dissolved in DCM (25 mL), washed with water and brine. After drying over MgSO4 the solvent was evaporated. The

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

• (BzQuTr) [42] and the cobalt precursor Co(NCS)2(py)4 [43], where py is pyridine. The reaction was performed under an argon atmosphere at room temperature. The resulting complex 1 was obtained after evaporation of the solvent, as a lilac precipitate in good yield (60%). The structure was investigated by

• -necked round-bottomed flask, under argon, the chelating ligand BzQuTr (100 mg, 0.35 mmol, 2.0 equiv) dissolved in 10 mL of dry MeOH was added dropwise to Co(NCS)2(py)4 (86 mg, 0.175 mmol, 1.00 equiv), dissolved in 5 mL of MeOH. The mixture was stirred for two hours at room temperature. The solvent was

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

• , 33600 Pessac, France 10.3762/bjoc.19.128 Abstract Electron and hole transport characteristics were evaluated for perylene-based and pyrene-based compounds using electron-only and hole-only devices. The perylene presented a columnar hexagonal liquid crystal phase at room temperature with strong

• observed mesophases. Compound 1 presents a wide range columnar hexagonal phase (Colhex) preserved at room temperature by cooling from the isotropic. Compound 2 shows an additional columnar rectangular phase (Colrect) below the Colhex and crystallizes under 166 °C. The HOMO and LUMO energy levels are also

• 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

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

• , in contrast to pure imidate 4. Pyrazolopyrimidine 8 was prepared by the reaction of 4 with N2H4∙H2O in EtOH according to our modification of the described procedure [40] using room temperature (without pre-cooling), a lower excess of N2H4∙H2O (1.6 equiv instead of 5 equiv) and a shorter reaction time

• (25 mL) and petroleum ether (50 mL), and 1 time with a mixture of ether (10 mL) and petroleum ether (20 mL) at room temperature. The extraction was considered as completed when the brown oil solidified. The product precipitated upon concentration of the combined extracts under reduced pressure. The

• added a solution of N2H4·H2O (2.470 g, 49.33 mmol) in EtOH (10 mL) over 3 min. The reaction mixture was stirred at room temperature for 1 h. The resulting suspension was cooled (−18 °C), the precipitate was filtered, washed with cold EtOH (4 × 15 mL), and dried to give compound 8 (5.152 g, 96%) as a

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

• was cooled to room temperature and set for slow evaporation of the solvent. 3-Methylsalicylaldehyde 3,4,5-trimethoxybenzoyl hydrazone, hdz-CH3. Yield 78%; mp 180 ± 1 °C; 1H NMR (400 MHz, DMSO-d6) δ (ppm) 2.22 (s, 3H), 3.74 (s, 3H), 3.88 (s, 6H), 6.86 (t, 3JHH = 7.52 Hz, 1H), 7.22 (d, 3JHH = 7.52 Hz

• structures of hdz-CH3 and hdz-NO2 can be seen in Figure S4 in Supporting Information File 1. Mid-infrared spectra of the compounds. Experimental conditions: KBr pellets, room temperature. Calculated conditions: gas phase, level of theory B3LYP/6-311G(d,p). (A) Overlapping of the theoretical (black) and

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• quinoxaline-4,4'-dicyanobenzene by manipulating the donor–acceptor conformation. The efficient TADF emission at room temperature highlighted the potential of these emitters for achieving high-performance OLEDs. The tunability of the emission peak through appropriate donor selection further demonstrates the

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• atmosphere at room temperature. They were analyzed by a Keithley 2400 source meter, a Hamamatsu Photonics PMA-12 multichannel analyzer, and an integrating sphere equipped with a Hamamatsu Photonics C9920-12 EQE measurement system. The hole and electron mobility were investigated using MIS-CELIV measurement

• to room temperature, the mixture was diluted with water (100 mL) and extracted with CH2Cl2 (50 mL × 3). The combined organic layer was washed with water, brine solution, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The crude product was then purified by column

• mmol) in dry toluene (50 mL) was degassed with N2 for 10 min. The reaction mixture was stirred at a refluxing temperature under N2 atmosphere for 48 h. After being cooled to room temperature, the mixture was diluted with water (100 mL) and extracted with CH2Cl2 (50 mL × 3). The combined organic layer

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• [34]. In the case of molecules with aryl Y-substituents – 1b2 and 1g2 – the room-temperature 1H and 13C NMR spectra (see Supporting Information File 1, Figures S2, S26 and S27, and reference [26]) display more resonances than expected based on the highest symmetry possible for the molecule indicating

• broadening and then coalescence of some of these peaks on increasing the temperature, consistent with the room-temperature spectrum being affected by restricted rotation; interestingly the crystal structure of 1b2 contains molecules with two very different conformations (see below). The 12 dimers are

• not react significantly with VII in solution at room temperature, while the reactions of 12 derivatives and VI are very rapid) [9][14][50][61]. Figure 8a compares the evolution of the absorbance at 1030 nm, corresponding to a VI•– absorption maximum, when doping excess VI with 1H derivatives in

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• expert botanist, Ms. Hiroko Murata (Setsunan University, retired). A voucher specimen (GPU-0812) has been deposited at the Gifu Pharmaceutical University for future reference. Extraction and isolation The dried roots (767 g) of B. disticha were extracted with MeOH (5 L × 3 times) at room temperature, and

Lewis acid-promoted direct synthesis of isoxazole derivatives

• Dengxu Qiu,
• Chenhui Jiang,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2023, 19, 1562–1567, doi:10.3762/bjoc.19.113

• TLC monitoring. Upon completion, the solution was cooled to room temperature and the solvent was removed under vacuum directly. The crude residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether 40:1) to afford product 3a with 87% yield. Natural products and drug

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• × 50 mm, Phenomenex), and Nucleosil 120 OH Diol (7 µm, 250 × 21 mm, Machery-Nagel, Düren, Germany) columns maintained at room temperature. Normal phase p-HPLC equipped with DAD detector (Agilent 1100 Series, Santa Clara, USA) was connected to a Nucleosil 120 OH Diol column. Deionized water used for RP

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• purification steps as a real environmentally benign synthetic process should as far as possible exclude organic solvents from all stages. In a first attempt, vanillin was reacted with rhodanine for 2 h at room temperature in Pro/Gly (1:2) and product 3a was obtained in 57% yield by a simple filtration after

• (0.5 mmol) were sequentially added to the DES and the reaction mixture was stirred at 60 °C for the indicated time. Then, water (10 mL) was added at room temperature and the formed precipitate was collected by filtration and washed with 10 mL of water. No further purification was needed. (Z)-5-(5

• solution of the corresponding synthesized compound (1.5 mL, 0.2 mM) was added to a DMSO solution of DPPH radicals (1.5 mL, 0.2 mM), so that the final concentration of DPPH radical and the synthesized compound in a solution was 0.1 mM. The mixture was shaken and allowed to stand at room temperature. After