Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• -substituted triazole 3’a (entry 1, Table 1), in 21% yield, using NiCl2(PCy3)2 as a catalyst and K3PO4 as a base. A methyl handle on the gem-difluoroalkene 1 was used to aid in 1H NMR analysis. The gem-difluoroalkenes were synthesized in one step using sodium 2-chloro-2,2-difluoroacetate and triphenylphosphine

• 19F NMR spectroscopy to monitor the consumption of the gem-difluoro starting material 1, which was completely consumed within 16 h (Figure 3). However, a 48 h time course gave a superior yield (Table 1, entry 13 vs entry 20). We hypothesize this might be due to the volatile nature of the gem

• morpholine as solvent (0.4 M) and 0.4 equiv LiHMDS as a base at 75 °C for 48 h. The only byproducts observed are anilines as a result of thermal decomposition of the organic azides via reactive nitrene species. No other byproducts were observed by TLC or crude 1H NMR. The volatility of the gem

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

• appearance of a solid–liquid biphasic mixture as the components of the DES are water-soluble. A large volume of water should be used since otherwise some DES traces are present in the NMR spectrum of the precipitate. Benzaldehydes having electron-donating or electron-withdrawing groups were studied as well

• -Hydroxymethylfurfurylidene)-2-thioxothiazolidin-4-one (3j). ochre yellow solid obtained after 1 h at 60 °C in 36% yield (two-step yield). Mp 149 °C; 1H NMR (400 MHz, DMSO-d6) δ (ppm) 4.49 (s, 2H), 5.52 (br s, 1H, OH), 6.58 (d, J = 3.6 Hz, 1H), 7.11 (d, J = 3.6 Hz, 1H), 7.44 (s, 1H, =CH), 13.62 (br s, 1H, NH); 13C NMR (100

• Information Supporting Information File 96: Experimental procedures, characterization of compounds, copies of NMR spectra and HRMS spectra. Acknowledgements The author acknowledges the NMR platform of the University of Lorraine, especially Sandrine Rup-Jacques and the MassLor platform, especially Jasmine

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• , these compounds are capable of forming complexes with small organic molecules. The current paper focuses on the synthesis of complexes between R[4]A and secondary aliphatic amines (sec-amines). Through NMR spectroscopy, it was observed that “in-out” complexes are formed depending on the solvent. It was

• amine, and the type of complex formed is influenced by the nature and polarity of the solvent. The stoichiometry and solvent-dependent structure of the “in-out” complexes formed were determined through NMR spectroscopy. Screening tests were carried out using the aISS-xTB2 method, while the final

• -polar solvents. When using N,N-dimethylamine, N,N-diethylamine, pyrrolidine, piperidine, morpholine and N-methylpiperazine as sec-amine component, the 1H NMR spectra reveal the formation of complexes with a 1:1 stoichiometry. However, for aliphatic amines with longer hydrocarbon chains, like

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• , followed by cyclization with glyoxal in formic acid. We then wished to slightly perturb the electron density via introduction of fluorine (either at R1 or R3), but it was at this time that an unexpected result was observed. Following the same conditions which produced B1, NMR evaluation of our next product

• –B14 as tested against 12 unique microbial species. Zones of inhibition of chelerythrine variants C1–C4 compared to chelerythrine (C). Supporting Information Supporting Information File 106: Synthetic procedures, characterization, methods for biological testing, and copies of NMR spectra of new

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• , the O-protonated forms ArC(=OH+)CH=CHCCl3, which are then cyclized into the target CCl3-indanones. These cations have been studied experimentally by means of NMR spectroscopy in TfOH and theoretically by DFT calculations. Under the same superacidic conditions in TfOH, CCl3-hydroxy ketones (1-aryl

• =CHC(=O)Me] with arenes in Brønsted superacid TfOH (triflic acid, CF3SO3H) furnishes 3-methyl-1-trichloromethylindenes (Scheme 1a) [11]. Based on NMR analysis in TfOH and theoretical DFT calculations, it has been found that the reaction proceeds through an intermediate formation of the O-protonated

• , we initiated this study on transformations of 1-aryl-4,4,4-trichlorobut-2-en-1-ones under superelectrophilic activation conditions (Scheme 1b). The main goals of this work were the investigation of the protonation of CCl3-enones (1-aryl-4,4,4-trichlorobut-2-en-1-ones) by NMR spectroscopy and DFT

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• isolated and structurally characterised through NMR spectroscopy (Supporting Information File 1, Table S2, Figures S4–S11) as compound 2 (Scheme 2A), a homolog of the 2MIBS side product 2-methylenebornane (6) (Scheme 2C). Analogously, the preparative scale conversion of DA-5 and IA-1 with FPPS and 2MIBS

• allowed for the isolation of the 2-methylisoborneol homolog 3 (Scheme 2B, Supporting Information File 1, Table S3 and Figures S12–S19). Furthermore, two inseparable hydrocarbons were obtained as a mixture (8:3) whose structures were tentatively assigned based on the NMR spectra (Supporting Information

• chromatography was performed using silica gel 60 (0.040–0.060 nm) purchased from Merck (Darmstadt, Germany). NMR spectra were recorded on a Bruker Avance I 500 MHz spectrometer and a Bruker Avance III HD 700 MHz Cryo spectrometer. Chemical shifts were referenced to the residual proton signal of C6D6 (δ = 7.16

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• –H bonds.a Optimization of the air-promoted 1,4-addition of dialkylzinc reagents onto N-(tert-butanesulfinyl) α-(aminomethyl)acrylates. Supporting Information Supporting Information File 94: General information, characterization data, chemical correlation, and copies of NMR spectra

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• NEt3·3HF, AgHF2 could also be used. The complexes were found to be air-stable in the solid state and moderately stable in solution. They were unambiguously characterized on the basis of NMR studies including 19F NMR and X-ray crystal analysis. With the IMes ligand, an air-stable bis(NHC)Cu(I) complex

• compounds, including diaryl- and dialkyl ketones and prochiral ketones, respectively (Scheme 36) [50]. Riant, Leyssens and co-workers investigated the mechanism of the hydrosilylation reaction of ketones using DFT, in situ FTIR, NMR, and kinetic methods [51][52]. The catalytic characteristics of sterically

• allow to synthesize acylboron compounds [54]. As mentioned earlier, Oro and co-workers [39] used 5 mol % of complex 78a (Scheme 27) for the homogeneous hydrosilylation of acetophenone with HSiEt3 in the presence of KOt-Bu. As indicated by 1H NMR spectroscopy, the conversion was complete in 18 h

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• 1), when after five days of hydrogenolysis and 0.8 equivalents of palladium at least 40% of impure divalent aminopyran derivative 25 was isolated. The major component of the isolated material is certainly fitting to the proposed structure according to the NMR data and their comparison with related

• several times by our group with good success for reductive ring-openings of 1,2-oxazine derivatives [63][64]. A slight excess of samarium diiodide in tetrahydrofuran completely consumed compound 21 within five hours. Compound 26 was isolated in 50% yield, but again the sample was not clean. The NMR data

• . Supporting Information Supporting Information File 86: Experimental procedures, spectroscopic and analytical characterization data of new compounds as well as copies of the NMR spectra. Acknowledgements We thank Dr. Reinhold Zimmer for his valuable assistance during preparation of the manuscript. Funding We

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• structures were elucidated by NMR spectroscopy, resulting in the discovery of the first terpene synthases for (+)-δ-cadinol and (+)-α-cadinene, besides the first two bacterial (−)-amorpha-4,11-diene synthases. For other terpene synthases with functions reported from bacteria before the products were

• ; biosynthesis; enzymes; NMR spectroscopy; terpenes; Introduction Terpene synthases are remarkable enzymes that can convert acyclic and achiral oligoprenyl pyrophosphates into terpene hydrocarbons or alcohols of high structural complexity. These enzymatic reactions are initiated by ionisation of the substrate

• accepted. A preparative scale incubation of FPP (80 mg, 185 μmol) allowed for the isolation of 10 (5.5 mg, 25 μmol, 14%) for structure elucidation through NMR spectroscopy (Table S2, Figures S3–S10, Supporting Information File 1), confirming the structure of δ-cadinol. The optical rotation of [α]D25

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• compounds 5 in yields between 11–69% after chromatographic workup. The structures of the products were unambiguously confirmed by 1H and 13C NMR spectroscopy, as well as by mass spectrometry. Assuming that four new bonds are being formed in this one-pot process, the range of yield from 11 to 69% (after

• -trisubstitued indoles 8 in good yield (Scheme 4). The 1,2,3-trisubstitued indoles 8 were unambiguously confirmed by 1H and 13C NMR spectroscopy, as well as by mass spectrometry and elemental analysis. Miura et al. could show that 1-alkyl-2,3-diarylindoles constitute a class of blue-emissive indole derivatives

• removed under vacuo. The residue was purified by chromatography on silica gel (n-hexane/ethyl acetate 100:1 to 5:1) to give pure compound 5d (243 mg, 69%) as a beige solid. Mp 118.2 °C; Rf 0.50 (n-hexane/ethyl acetate 10:1); 1H NMR (600 MHz, CDCl3) δ 3.68 (s, 3H), 7.02–7.07 (m, 1H), 7.17–7.20 (m, 1H

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• Supporting Information File 188: Experimental procedures, product characterization, and copies of NMR spectra. Funding National Natural Science Foundation of China (21991121), National Key Research and Development Program of China (2021YFF0701700), Natural Science Foundation of Shandong Province

Correction: Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 1370–1371, doi:10.3762/bjoc.19.97

• publication was misattributed and should be revised as shown in Figure 1. The error happened due to insufficient in-depth 2D NMR analysis. We reanalyzed the 2D NMR data of compound 1 in detail and finally determined the correct structure as shown in Figure 1. The revised structure of 1 is supported by the

• HMBC correlations of H-2/C-1, C-3, C-4, C-8a, H-4/C-3, C-4a, C-5, C-8a, C-9, H-5/C-4, C-4a, C-6, C-7, C-8a, H-9/C-2, C-3, C-4, H-10/C-7, C-8, C-8a, H-11/C-6, and H-12/C-7. Table 1 provides the revised 1D 1H and 13C NMR data of compound 1. The structural revision of 1 also required recalculation of the

• compound 1 and key HMBC correlations. Recalculated and experimental ECD spectra of compound 1. Revised 1H (600 MHz) and 13C NMR (150 MHz) data of compound 1 (δ in ppm, J in Hz, methanol-d4).

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• , and 1H/13C NMR spectroscopy. Proton NMR shows a complicated set of overlapping multiplets indicating that the reaction results in the formation of various isomers (rotamers) which are different by relative orientation of the benzoguanidine donor moieties with respect to each other (Figure 2, see

• Supporting Information File 1 for NMR). In DMSO-d6 solution, 4BGIPN isomers do not show interconversion even upon warming to 120 °C, resulting in a similar set of signals. Excellent fit between HRMS and elemental analysis further supports the formation of the isomeric mixture of 4BGIPN as evidenced by the

• mineral oil with diethyl ether and dried prior to use. 5H-Benzo[d]benzo[4,5]imidazo[1,2-a]imidazole (benzoguanidine) was obtained according to the literature protocol [10] while 2,4,5,6-tetrafluoroisophthalonitrile was purchased from Fluorochem Ltd. and used as received. 1H and 13C{1H} NMR spectra were

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• :45 and 59:41 mixtures of inseparable diastereomers, respectively. The relative diastereomeric ratios (dr) were determined by means of 1H NMR based on the proton at the α-position of the EWG moiety (Table 3). In order to explore the scope of this synthetic approach, we have studied the reaction of

• ) onto acyclic MBH alcohols 1a–f. Supporting Information Supporting Information File 69: Full experimental details and characterization data of all new compounds. Supporting Information File 70: 1H and 13C NMR and HRMS spectra of compounds. Acknowledgements We thank the Tunisian Chemical Society for

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• %) were added to a solution of 1 (10 mol %) in 2 mL of solvent (0.25 M) and allowed to stir for 48 hours at room temperature. Yields of isolated compounds are given. Diastereomeric ratio (dr) determined by 1H NMR analysis. Enatiomeric excess (ee) determined by chiral HPLC analysis. Original triple

• : Experimental part, NMR and HPLC spectra. Funding Fabio Pesciaioli thanks the Ministero dell'Università e della Ricerca (PON-AIM1842894, CUPE18D19000560001) for funding this research. Maria Edith Casacchia thanks the support of the Italian national inter-university Ph.D. course in Sustainable Development and

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• structures of the obtained dispiro compounds 3a–m were fully characterized by IR, HRMS, 1H and 13C NMR spectroscopy. Because of the three chiral carbon atoms in the product, several diastereomers might be formed in the reaction. However, TLC monitoring and 1H NMR spectra of the crude products clearly

• group in the neighboring oxindole scaffold. Therefore, it can be concluded that the obtained dispiro compounds 3a–m have this kind of relative configuration on the basis of 1H NMR spectra and crystal structure determination. It should be pointed out that ammonium acetate was employed as nitrogen source

• is largely general. The 1H NMR spectra of the obtained compounds 4j–p clearly show similar chemical shifts of the characteristic groups as the spiro compounds 4a–i. Therefore, it can be concluded that the spiro compounds 4j–p have the same relative configuration as the spiro compounds 4a–i. In order

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• copper(II) porphyrins 3–8. Finally, the structures of all newly synthesized benzo[f]chromeno[2,3-h]quinoxalinoporphyrins 3–16 and benzo[f]quinoxalinoporphyrin 17 were assigned on the basis of IR, 1H and 13C NMR, and HRMS data analysis. Photophysical characteristics The UV–vis spectra of the newly

• received unless otherwise stated. The column chromatographic purifications of all products were carried out using either activated neutral aluminium oxide (Brokmann grade I-II, Merck). The melting points of all newly prepared products were determined on a Büchi M-560 melting point apparatus. 1H NMR (400

• MHz) and 13C NMR (100 MHz) spectra were recorded in CDCl3 on a Jeol ECX-400P (400 MHz) NMR spectrometer. Chemical shifts are reported in δ scale in parts per million (ppm) relative to CDCl3 (δ = 7.26 ppm for 1H NMR and δ = 77.00 ppm for 13C NMR). The coupling constants are expressed as (J) and are

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• catalysts in an acetonitrile/water mixture [46]. They used combinations of deuterated solvents and 1H NMR spectroscopy to confirm that water was the main source of the protons for the regeneration. Furthermore, they successfully replaced ruthenium photosensitizers with organic dyes so that the system used

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

• Valeriy O. Filimonov,
• Alexandra I. Topchiy,
• Vladimir G. Ilkin,
• Tetyana V. Beryozkina and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2023, 19, 1191–1197, doi:10.3762/bjoc.19.87

• pyrazoles has been thus synthesized. The structure of the reaction products was studied using NMR spectroscopy and mass spectrometry and confirmed by X-ray diffraction analysis. Keywords: aminopyrazoles; 2-cyanothioacetamides; enamines; hydrazines; Introduction Compounds containing a pyrazole cycle

• -diaminopyrazoles 4a–c (Scheme 2). The structures of compounds 4a–c were confirmed by 1H and 13C NMR spectroscopy data, as well as high-resolution mass spectrometry (HRMS). Compound 4a was previously obtained by another method [18]. The spectral characteristics of diaminopyrazole 4a reported in [18] correspond to

• group during the reaction. The structures of compounds 5a–e were confirmed by 1H and 13C NMR spectroscopy and HRMS, as well as X-ray diffraction analysis of a single crystal of compound 5b. The involvement of arylhydrazines 3b,c in the reaction with enamines 2a–d similarly leads to the formation of 1

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• have been evaluated extensively through both qualitative and quantitative means. Methods of evaluation have included X-ray crystallography and spectroscopy (e.g., microwave, IR, Raman, NMR, NQR), as well as through computational determination of their electrostatic VS,max potentials (Figure 2), their

• . used 1H NMR titrations and isothermal titration calorimetry (ITC) to experimentally determine interactions energies for I-9 complexes (e.g., I-9-lig, −6.3 kcal/mol), they also discovered that simultaneous binding to both σ-holes was possible [90]. Given these observations, it is unsurprising that HVI

Retraction: One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2023, 19, 1170–1170, doi:10.3762/bjoc.19.85

• ; thiourea; This article was retracted due to the improper manipulation of NMR spectra with the help of software to obscure peaks corresponding to impurities and solvent.

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• ). The structures of the isolated compounds were established based on HRESIMS and extensive 1D and 2D NMR experiments. All the isolated compounds were assessed for their antimicrobial and cytotoxic activities. Among the tested compounds, forpinioside B (1) exhibited significant antimicrobial activity

• unsaturation in its structure. The 1H, 13C NMR, and HSQC spectral data of compound 1 (Table 1) revealed the presence of forty-three carbon resonances sorted into eight methyl, fourteen methylenes (one olefinic), ten methine and eleven unprotonated carbon atoms. This includes three carbonyl carbons at δC 177.4

• (C-21), 175.0 (C-5'), and 172.4 (C-1') as well as four olefinic carbon signals at δC 156.7 (C-24), 136.3 (C-9), 135.2 (C-8), and 107.4 (C-31). The 1H and 13C NMR spectral data of compound 1 (Table 1) also revealed the presence of a sugar moiety through the presence of the characteristic anomeric

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• Information Supporting Information File 124: Experimental procedures, characterization data, and 1H and 13C NMR spectra for all new compounds. Funding This work was supported by the Russian Science Foundation (grant No. 22-13-00356).