Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• ethanol to yield the title compound as a light gray powder (4.05 g, 72%). 1H NMR (400 MHz, DMSO-d6) δ 9.72 (s, 1H), 7.91 (d, J = 8.7 Hz, 2H), 7.76 (t, J = 6.9 Hz, 2H), 7.41 (t, J = 7.3 Hz, 1H), 7.35 (d, J = 1.8 Hz, 1H), 7.29 (m, 2H), 7.71 (dd, J = 8.3, 1.8 Hz, 1H), 6.90 (d, J = 8.2 Hz, 1H), 5.70 (s, 1H

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• ethanol, and the reaction mixture was refluxed for 8 hours. The progress of the reaction was monitored by TLC. After completion, the reaction mixture was cooled to room temperature and the solvent was removed under reduced pressure. The resulting residue was dissolved in 30 mL of chloroform and washed

• , 1182, 1060, 941, 823, 545 cm−1. Synthetic procedure of compound 12 Bromonaphthalic anhydride (1.3 g, 4.8 mmol) was added to a stirred solution of amine 11 (1.0 g, 4.8 mmol) in ethanol (25 mL). The reaction mixture was refluxed for 2 h, and the progress of the reaction was monitored by TLC. After

• completion, the reaction mixture was allowed to cool to room temperature, and the resulting precipitate was filtered, washed with ethanol, and dried to afford bromo compound 12 as an off-white powder (1.5 g, 66%). mp: 125 °C; 1H NMR (400 MHz, CDCl3) δ 8.64 (d, J = 7.2 Hz, 1H), 8.56 (d, J = 8.6 Hz, 1H), 8.39

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• homogeneous reduction using tin(II) chloride in ethanol was used after fine-tuning of the published reaction conditions [9]: the reduction was conducted by gentle heating of a mixture of calixarene 11, SnCl2·2H2O, aqueous HCl and ethanol at 70 °C (instead of prolonged boiling of the reaction mixture) in a

Dialkylaminoalkylation of β-ketosulfones via ring-opening of 3-sulfonylpyrrolidines

• Evgeny M. Buev,
• Alexander V. Pavlushin,
• Vladimir S. Moshkin and
• Vyacheslav Y. Sosnovskikh

Beilstein J. Org. Chem. 2026, 22, 383–389, doi:10.3762/bjoc.22.26

• modifications and the use of the obtained compounds as building blocks. We also examined other nucleophiles suitable for the described domino-sequence. Thus, application of ethanol as solvent resulted in a mixture of the desired product 4b with the corresponding intermediate C (NMR ratio 88:12), however, longer

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• enabled the formation of ethyl ester 75 and benzoxazole 76 when ethanol and 2-aminophenol were employed as nucleophiles, respectively. Chen et al. recently investigated an environmentally benign approach to amide C–N bond cleavage using electrochemical activation (Scheme 14) [62]. In the presence of

• nucleophiles with alcohols enables esterification of the amide (Scheme 20) [68]. Using ethanol, isopropanol, and phenol as nucleophiles, the sterically demanding α-adamantyl N,N-dimethylamide was efficiently converted into the corresponding esters 147–152 in high to excellent yields, whereas the extremely

• bidentate chelation, as depicted in the proposed transition state AH, which facilitates nucleophilic attack of alcohols at the carbonyl center and subsequent C–N bond cleavage. Under the optimized conditions, tert-butyl benzamidonicotinate reacted smoothly with methanol, ethanol, and butanol to afford alkyl

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• the presence of catalytic DMF in ethanol (Scheme 3a) [40]. A small amount of ethanol ensured homogeneity of the reaction mixture, allowed gradual temperature increase, and prevented sudden charring. DMF, with its high boiling point, acted as a homogenizer by preventing solidification after ethanol

• -unsaturated malonate 6 with 2a–c, various bases (sodium methoxide, triethylamine, potassium hydroxide) and solvents (ethanol, DMF, pyridine) were tested, mostly at room temperature, with an additional attempt at refluxing in ethanol/DMF. The desired malonate Michael adduct 7 (isolated and fully characterized

• boiling methanol in the presence of ʟ-proline yielded the corresponding methyl esters 10a–c in good yields (57–69%). Similarly, using ethanol under the same conditions afforded the ethyl esters 9a–c with moderate yields (46–50%). Thus, we developed a novel multicomponent organocatalyzed cascade reaction

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• Technology Co., Ltd.; 3-(9H-carbazol-9-yl)phenylboronic acid (5) was obtained from Sukailu Co., Ltd.; glacial acetic acid, anhydrous sodium sulfate, dichloromethane, n-hexane, ethanol, chloroform, and tetrahydrofuran were supplied by Guangzhou Chemical Reagents Co., Ltd. All reagents were used as received

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• afforded product 2a in a slightly decreased yield (44%, Table 1, entry 7). To our surprise, when ethanol was replaced with methanol, the deacylated product 3a was isolated as the major product in 71% yield (Table 1, entry 8). In this case, dihydrothiophene 2a formed only in a trace amount. In contact with

• % (Table 2, entry 2). In a more concentrated ethanol solution (1 mL) the product was obtained in 70% yield (Table 2, entry 3). When the residue was quenched with concentrated HCl (1 mL), the product was isolated in reduced yield (58%, Table 2, entry 4). Adding 0.25 mL of acid (HCl) after quenching the

• ethanol (Scheme 5, VII). However, under these conditions only decomposition of 4g was observed, and neither deacetylated nor hydroxylated products were isolated. Interestingly, chromatography of 4g on neutral alumina resulted in elimination of the sulfonylimine group to give compounds 5g. Therefore, the

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• recrystallized from ethanol (Figure 3, purple), a similar pattern is observed, indicating a high degree of crystallinity. Furthermore, samples of 1·HCl prepared either by rapid precipitation in organic solvents, as described in the Experimental section (red), or material isolated from a saturated solution of 1

• -NBOH (1), providing easier access to this compound. When the hydrochloride salt 1·HCl was precipitated and recrystallized from ethanol, a single and stable, nonhygroscopic polymorph with a well-defined melting point formed. A crystal structure determined by SCXRD confirmed the structural assignment

• ). Acetonitrile (Ph. Eur.), absolute ethanol (Reag. Ph. Eur.), ethyl acetate (HPLC grade), dichloromethane (HPLC grade), ammonia (25%, analytical reagent grade), and diethyl ether (reagent grade) were purchased from VWR (Radnor, PA, USA). Sodium hydrogencitrate sesquihydrate (99%), salicylaldehyde (≥98

Circumventing Mukaiyama oxidation: selective S–O bond formation via sulfenamide–alcohol coupling

• Guoling Huang,
• Huarui Zhu,
• Shuting Zhou,
• Wanlin Zheng,
• Fangpeng Liang,
• Zhibo Zhao,
• Yifei Chen and
• Xunbo Lu

Beilstein J. Org. Chem. 2026, 22, 158–166, doi:10.3762/bjoc.22.9

• investigated the scope of alcohols in the NBS-promoted coupling with sulfenamides under the optimized conditions (Scheme 4). A series of linear alcohols, including simple aliphatic alcohols such as ethanol, 1-propanol, 1-butanol, and 1-octanol, as well as aromatic-substituted alcohols like 3-phenyl-1-propanol

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• ) dissolved in water (7.5 mL) was added and the solution was stirred at room temperature for 19 h. Water (15 mL) was added to the yellow solution and the ethanol was removed by evaporation in vacuo. Water (10 mL) was added and the solution was neutralized with aqueous HCl solution (0.50 mL of conc. HCl

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• ], diammonium phosphate (DAP) [43], and tetrabutylammonium bromide (TBAB) [44]. Organic bases like morpholine [45], triethylamine [46], ethanolamine, and piperidine [47] and heterogeneous catalysts from Cu [48], Ti [49], and Zn [50] metal compounds have also been used. Common solvents are ethanol [51], toluene

• to replace AcOH by ethanol (Table 1, entry 10), however, the use of ethanol with piperidine was controversial. We found out that, during the reaction with benzaldehyde (1a) and rhodanine (2a), a multicomponent reaction was taking place by a substitution process, leading directly to 2-amino-5

• (H3PW12O40, HPW) as a catalyst in ethanol under microwave (μw) heating (Scheme 5) [63]. These intermediates were then subjected to the previously optimized Knoevenagel condensation conditions with rhodanine or thiazolidine-2,4-dione (Scheme 6). Notably, the hybrid compounds 9a–d, 10a–d were obtained in good

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• toluene, ethanol and acetone to remove unreacted APTES and dried in vacuo (50 °C) overnight in order to get a-SG [15][16]. Further, to prepare covalent SG-NHCO-BU1, a-SG (0.9 g) was suspended in DMF (15 mL) and shaken at ambient temperature for 30 min. BU1 (0.1 g, 1 equiv) was dissolved in a minimum

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• , entry 1). However, methanol proved to be an ineffective solvent due to the rapid decomposition of NaBH4 and poor solubility of substrate 3. Most of the starting material was recovered unchanged after complete decomposing NaBH4. In contrast, when ethanol (Table 2, entry 2) or isopropanol (Table 2, entry

• , but it was obtained as a mixture of ester forms, namely dimethyl and diethyl esters in ethanol, and dimethyl and diisopropyl esters in isopropanol. These results indicate that the reaction with alcohol solvents resulted in partial transesterification of the methoxycarbonyl groups, while reductive

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• aqueous-phase reforming (APR) technology for the production of light hydrocarbons and hydrogen in a single step from aqueous organic phases [97] containing 1-hydroxypropan-2-one (acetol), ethanol, benzene-1,2-diol (catechol), acetic acid or mixtures thereof. The process was conducted over various Ni-based

• -hydroxypropan-2-one and KSCN in ethanol for further evaluation of their anti-cancerous activity by MTT assays (Scheme 24) [99]. Notz and List reported the synthesis of anti-diols in good yield from 1-hydroxypropan-2-one and different (aromatic and aliphatic) substituted aldehydes using a new strategy using ʟ

• of Lewis acid–base bifunctional catalyst (Zr-β zeolite and K2CO3) in the Meerwein–Ponndorf–Verley reduction of a concentrated furfural solution (17.3–80.5 wt % in ethanol) combined with in situ cross-aldol condensation with acetaldehyde and crotonization. Ethanol was used as hydrogen donor for the

Convenient alternative synthesis of the Malassezia-derived virulence factor malassezione and related compounds

• Karu Ramesh and
• Stephen L. Bearne

Beilstein J. Org. Chem. 2025, 21, 1730–1736, doi:10.3762/bjoc.21.135

• ) and dissolved in ethanol (3 mL). A catalytic amount of Pd/C was then added and hydrogenolysis was conducted for 4 h with stirring under an H2-filled balloon. The reaction was monitored by TLC and, after completion of the reaction, the mixture was filtered through Celite, followed by washing of the

• remaining Pd/C with ethanol (3 × 5 mL). The solvent was removed by evaporation under reduced pressure and the resulting crude compound was purified by chromatography on silica gel (hexane/EtOAc; 90:10) to afford 25c as a white solid (41 mg, 73%); mp 154–156 °C (lit. mp 164 °C [22]; 150–152 °C [35]; 157–158

Calcium waste as a catalyst in the transesterification for demanding esters: scalability perspective

• Anton N. Potorochenko and
• Konstantin S. Rodygin

Beilstein J. Org. Chem. 2025, 21, 1520–1527, doi:10.3762/bjoc.21.114

• complete transesterification reaction. The corresponding esters 3a and 3e were obtained in 99% and 97% yields. For ethanol and n-butanol, the required amount of the catalyst was 5 wt %; the yields of esters 3b and 3c were 91% and 78% with reaction times of 3 and 5 hours, respectively. Similar results were

Highly distinguishable isomeric states of a tripodal arylazopyrazole derivative on graphite through electron/hole-induced switching at ambient conditions

• Himani Malik,
• Sudha Devi,
• Debapriya Gupta,
• Ankit Kumar Gaur,
• Sugumar Venkataramani and
• Thiruvancheril G. Gopakumar

Beilstein J. Org. Chem. 2025, 21, 1496–1507, doi:10.3762/bjoc.21.112

• , which reveals that the majority (>98%) of molecules in the solution are in the thermodynamically stable EEE form (see Supporting Information File 1, section 4 for a UV–vis spectrum of FNAAP in ethanol–chloroform mixture, which resembles the reported spectrum in chloroform [29]). Long 1D islands are

• were subjected to control AFM experiments to check for any contamination or impurities on the surface. We also note that no traces of ethanol remained on the surface after pumping, as confirmed by AFM images. Instrumentation All AFM and STM measurements were performed using an Agilent 5500 in soft

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• . SIPERNAT 320 amorphous silica was supplied by Evonik. Reactions were monitored by TLC on Merck 60 F254 (0.25 mm) plates (Milan, Italy), which were visualised by UV inspection and/or by heating after spraying with 0.5% ninhydrin in ethanol or phosphomolybdic acid. Homogeneously catalysed reactions were

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• thioamides 1h,i,k,n,o,s,t,v,w,y,z (general procedure). A mixture of the corresponding thioacetamide (1.0 equiv), aldehyde (1.1–4.0 equiv) and DBU (0.1 equiv or 1.0 equiv for 1h,o) in ethanol was stirred for 2–23 h at room temperature. For thioamide 1i, the reaction time was 96 h at 80 °C. The formed

• precipitate was filtered off and washed with cold ethanol and diethyl ether. Preparation of 2-sulfonyl-2,3-dihydro-1,2-thiazoles 3 (general procedure). Method A. The corresponding thioamide 1 (1.0 equiv) and DCM (1 mL) was added to an oven-dried standard microwave vial with a volume of 10 mL. The resulting

Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents

• Julius Krenzer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97

• -N-benzylbenzothiazolium salts in 1,4-dioxane at room temperature in short reaction time in 20–99% yield. This protocol represents a considerable improvement over the standard synthesis in 1,4-dioxane/ethanol mixtures at elevated temperatures. Keywords: aroyl chlorides; aroyl-S,N-ketene acetals

• of an amine base in a binary 1,4-dioxane/ethanol mixture. Ethanol was used as a cosolvent to ensure solubility of the polar intermediate according to the mechanistic rationale (Scheme 2) [5][6]. Although, a broad scope of diversely substituted (hetero)aroyl-S,N-ketene acetals 8 was obtained (111

• presumed byproducts in the addition–elimination sequence in the presence of an excess of ethanol as a cosolvent are the ethyl ester formed by Einhorn acylation [7] of the acid chloride under the standard conditions and deep colored polar byproducts (according to TLC detection) that arise from self

Synthetic approach to borrelidin fragments: focus on key intermediates

• Yudhi Dwi Kurniawan,
• Zetryana Puteri Tachrim,
• Teni Ernawati,
• Faris Hermawan,
• Ima Nurasiyah and
• Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

• % yield over three steps. This compound was isolated in its pure form as a white solid after recrystallization from ethanol, confirmed by HPLC and NMR. In parallel, the primary alcohol group of ent-38 was protected as a TBDMS ether, and the acetate group was converted to a tosyl ester by hydrolyzing the

• reduced with LiAlH4 to remove the OTs group, and after silyl group removal, diol 32b was obtained in 92% yield. Protection of the primary alcohol as a tosyl ester and the secondary as a TBDMS ether afforded intermediate 32c (72%). This intermediate was then treated with sodium thiophenol in ethanol

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• , dried over sodium sulfate, and freshly distilled prior to use. All solid aldehydes were used after recrystallization from petroleum ether (PE, 60–90 °C fraction) or a mixture of ethanol and water. All dialkyl 3-aryl-1-sulfonylaziridine-2,2-dicarboxylates 1 were synthesized by previously reported

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• alkyldiamines proceeded with solvent-independent regioselectivity, exclusively furnished [2 + 2] macrocyclic adducts. Strikingly, when 37 was combined with 2,2’-oxybis(ethylamine) (38), the reaction pathway exhibited pronounced solvent dependency. Reactions in methanol, ethanol, or chloroform selectively

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• -pyrroline-2-ones 1a–e and 4-methoxybenzylamine (2) in absolute ethanol yielded 4-[1-(4-methoxybenzyl)amino]ethylidene-1,5-disubstituted pyrrolidine-2,3-diones 3a–e (Scheme 1) [19][20][21]. In addition to nuclear magnetic resonance spectroscopy (1D, 2D NMR), the structure of 3a has also been proven via

• pyrrolidine-2,3-diones 3b–e are not expected to affect the scope of the reaction (Scheme 2, Table 1). When the reaction between 3a (1 equiv) and methylamine (4) (4 equiv, 40% in water) was carried out in absolute ethanol (0.3 mL) at reflux, 4-(1-methylamino)ethylidene-1,5-diphenylpyrrolidine-2,3-dione (5a