Molbank

5 pages, 234 KB

Open AccessCommunication

Synthesis and Characterization of Novel Pyridinium Salts of (E)-2-(Pyridin-4-ylmethylene)hydrazine-1-carboximidamide

by Fatemeh Ataie Alani, Fatemeh Ahmadian, Alireza Houshdar Tehrani and Salimeh Amidi

Molbank 2025, 2025(4), M2068; https://doi.org/10.3390/M2068 - 1 Oct 2025

We report the synthesis and characterization of the novel pyridinium salts from (E)-2-(pyridin-4-ylmethylene)hydrazine-1-carboximidamide. The pyridinium salts were obtained via the reaction of guanylhydrazone derived from pyridine-4-carbaldehyde with phenacyl bromides. Structural characterization was carried out using IR, ¹H, and ¹³C [...] Read more.

We report the synthesis and characterization of the novel pyridinium salts from (E)-2-(pyridin-4-ylmethylene)hydrazine-1-carboximidamide. The pyridinium salts were obtained via the reaction of guanylhydrazone derived from pyridine-4-carbaldehyde with phenacyl bromides. Structural characterization was carried out using IR, ¹H, and ¹³C NMR spectroscopy and mass spectrometry. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Scheme 1

8 pages, 1375 KB

Open AccessShort Note

3-(4-Hydroxy-2,3,5-trimethylphenyl)-3-(4-hydroxyphenyl)isobenzofuran-1(3H)-one

by Brian A. Chalmers, David B. Cordes, Aidan P. McKay, Iain L. J. Patterson, Russell J. Pearson, Nadiia Vladymyrova and Iain A. Smellie

Molbank 2025, 2025(4), M2067; https://doi.org/10.3390/M2067 - 1 Oct 2025

Abstract

3-(4-hydroxy-2,3,5-trimethylphenyl)-3-(4-hydroxyphenyl)isobenzofuran-1(3H)-one is a derivative of the well-known acid/base indicator, phenolphthalein. We report the synthesis and the molecular structure of the title compound as determined by single-crystal X-ray diffraction. ¹H and ¹³C NMR spectroscopy, IR spectroscopy, and mass spectrometry data have been provided. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 565 KB

Open AccessShort Note

(±)-2-(4-Isobutylphenyl)-N-(naphthalen-1-yl)propanamide

by Diyana Dimitrova, Iliyan Ivanov, Stanimir Manolov and Dimitar Bojilov

Molbank 2025, 2025(4), M2065; https://doi.org/10.3390/M2065 - 30 Sep 2025

Abstract

We describe the synthesis of (±)-2-(4-isobutylphenyl)-N-(naphthalen-1-yl)propanamide, followed by comprehensive structural characterization. The compound was analyzed through melting point determination, ¹H and ¹³C NMR spectroscopy, infrared spectroscopy, and mass spectrometry. The concordant results from these techniques provide clear evidence for [...] Read more.

We describe the synthesis of (±)-2-(4-isobutylphenyl)-N-(naphthalen-1-yl)propanamide, followed by comprehensive structural characterization. The compound was analyzed through melting point determination, ¹H and ¹³C NMR spectroscopy, infrared spectroscopy, and mass spectrometry. The concordant results from these techniques provide clear evidence for the successful preparation and structural confirmation of the target molecule. Full article

(This article belongs to the Section Structure Determination)

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7 pages, 862 KB

Open AccessShort Note

Dichloro[2,5-bis(diisopropylphosphorimidoyl-κN-(4,6-dimethylpyrimidine-κN))pyrrole-κN]yttrium(III)·toluene

by Emily L. Trew, David Szucs and Paul G. Hayes

Molbank 2025, 2025(4), M2066; https://doi.org/10.3390/M2066 - 30 Sep 2025

Abstract

The compound dichloro[bis(diisopropylphosphorimidoyl-κN-(4,6-dimethylpyrimidine-κN))pyrrole-κN]yttrium(III) was synthesized from one equivalent of NaL [L = 2,5-[ⁱPr₂P=N(Pym^Me)]₂NH(C₄H₂); Pym^Me = 4,6-dimethylpyrimidine] and YCl₃(THF)_3.5 and crystallized from [...] Read more.

The compound dichloro[bis(diisopropylphosphorimidoyl-κN-(4,6-dimethylpyrimidine-κN))pyrrole-κN]yttrium(III) was synthesized from one equivalent of NaL [L = 2,5-[ⁱPr₂P=N(Pym^Me)]₂NH(C₄H₂); Pym^Me = 4,6-dimethylpyrimidine] and YCl₃(THF)_3.5 and crystallized from toluene. X-ray quality crystals of LYCl₂ were obtained with one toluene solvent molecule in the asymmetric unit. The geometry, bond lengths and angles were analyzed and found to contain similar parameters to comparable structures in the literature, and the product was further characterized by NMR spectroscopy. To the best of our knowledge, this is the first reported seven-coordinate Y(III) complex supported by a pentadentate ligand wherein all five donor atoms are nitrogen. Full article

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6 pages, 1397 KB

Open AccessCommunication

A Tandem Photocycloaddition—Ring Expansion Strategy for the Synthesis of Fused [5.3.0] Triketone

by Xin-Yi Hsiao, Chern Chuang and Gary Jing Chuang

Molbank 2025, 2025(3), M2064; https://doi.org/10.3390/M2064 - 22 Sep 2025

Abstract

A tandem synthetic sequence involving photo-induced intramolecular [2+2] cycloaddition followed by acid-promoted ring expansion was developed to access the novel bicyclic triketone framework. The process begins with the UV (254 nm) irradiation of cyclic vinylogous ester, affording a highly strained cyclobutane-fused diketone in [...] Read more.

A tandem synthetic sequence involving photo-induced intramolecular [2+2] cycloaddition followed by acid-promoted ring expansion was developed to access the novel bicyclic triketone framework. The process begins with the UV (254 nm) irradiation of cyclic vinylogous ester, affording a highly strained cyclobutane-fused diketone in an 86% yield. This unique intermediate feature is of a fused four- and six-membered ring system with spatially compressed carbonyl groups. Upon acidic hydrolysis in aqueous MeCN, the strained system undergoes retro-aldol ring expansion, delivering [5.3.0] bicyclic triketones bearing a seven- and five-membered fused ring with three strategically oriented carbonyl units in a 75% yield. Structural elucidation was performed using NMR spectroscopy, UV-Vis, HRMS, and single-crystal X-ray crystallography. The method highlights a concise route for constructing a fused bicyclic triketone of relevance to synthetic and medicinal chemistry. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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5 pages, 192 KB

Open AccessShort Note

1,1,1,3,3,3-Hexafluoropropan-2-yl 2,3,5,6-tetrafluoro-4-((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)benzoate

by Sofia S. Kascheeva, Anastasiya V. Lastovka, Andrey S. Vinogradov and Dmitriy A. Parkhomenko

Molbank 2025, 2025(3), M2063; https://doi.org/10.3390/M2063 - 18 Sep 2025

Abstract

Acyl chloride alcoholysis is a fundamental and typically high-yielding method for ester synthesis. However, competitive side reactions can occur when the acyl chloride possesses multiple electrophilic sites and the alcohol is a strong nucleophile. We report an example of this phenomenon: the reaction [...] Read more.

Acyl chloride alcoholysis is a fundamental and typically high-yielding method for ester synthesis. However, competitive side reactions can occur when the acyl chloride possesses multiple electrophilic sites and the alcohol is a strong nucleophile. We report an example of this phenomenon: the reaction of pentafluorobenzoyl chloride with 1,1,1,3,3,3-hexafluoropropan-2-ol yields not only the expected ester but also a significant quantity of the 1,1,1,3,3,3-hexafluoropropan-2-yl 2,3,5,6-tetrafluoro-4-((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)benzoate. The formation of the latter results from an effective nucleophilic aromatic substitution (S_NAr) at the para-fluorine position of the pentafluorophenyl ring by the hexafluoroisopropoxide anion. Full article

(This article belongs to the Collection Molecules from Side Reactions)

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Scheme 1

3 pages, 247 KB

Open AccessShort Note

1-((Dimethyl(3-((2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl)oxy)propyl)silyl)oxy)-3,5,7,9,11,13,15-heptakis((dimethylsilyl)oxy)-octasilsesquioxane

by Analise C. H. Migliaccio, Andrea R. Kelley and Scott T. Iacono

Molbank 2025, 2025(3), M2062; https://doi.org/10.3390/M2062 - 17 Sep 2025

Abstract

The title compound was synthesized using Pt-catalyzed hydrosilylation of octasilane POSS and allyl 1H,1H-perfluorooctyl ether. The purity and structure were determined by NMR (¹H, ¹³C, ¹⁹F, ²⁹Si), and MALDI TOF-MS. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Scheme 1

5 pages, 424 KB

Open AccessShort Note

(R)-4-Acetyl-10-(2-chloro-1,3-thiazol-4-yl)-5,11,13-trihydroxy-2,12-dimethyl-8-oxatricyclo[7.4.0.0^2,7]trideca-1(13),4,6,9,11-pentaen-3-one

by Aleksandr S. Filimonov, Olga A. Luzina and Nariman F. Salakhutdinov

Molbank 2025, 2025(3), M2061; https://doi.org/10.3390/M2061 - 16 Sep 2025

Abstract

A novel usnic acid derivative with 2-chlorothiazole substituent was obtained by a three-step synthesis from usnic acid. The structure of the product was proved by a set of physical methods, including ¹H, ¹³C, HRMS, HSQC, HMBC and IR spectroscopy. Full article

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8 pages, 1038 KB

Open AccessShort Note

Allyl Syringate

by Naruedech Thimpa, Suriyaphong Poprom, Laksakarn Songpao and Nawasit Chotsaeng

Molbank 2025, 2025(3), M2060; https://doi.org/10.3390/M2060 - 15 Sep 2025

Abstract

Syringic acid (1) is a naturally occurring compound with diverse biological activities. Structural modification of syringic acid often enhances its utility; however, the spectroscopic data for several derivatives remain unreported, and the procedures to obtain them can be synthetically challenging. In [...] Read more.

Syringic acid (1) is a naturally occurring compound with diverse biological activities. Structural modification of syringic acid often enhances its utility; however, the spectroscopic data for several derivatives remain unreported, and the procedures to obtain them can be synthetically challenging. In this study, we report the allylation of syringic acid (1) to afford a novel derivative, allyl syringate (1c). The structure of this compound was confirmed by IR, NMR, and MS spectroscopy and compared with those of closely related derivatives (1a and 1b). These findings provide a useful foundation for further studies on the allylation of syringic acid and related phenolic acid derivatives. Full article

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6 pages, 724 KB

Open AccessShort Note

4,11-Dimethyl-2,13-di-m-tolyltribenzo[b,e,g][1,4]dioxocine-7,8-dicarbonitrile

by Dmitry Erzunov, Vyacheslav Baklagin, Vladimir Bukhalin, Igor Abramov, Kyrill Yu. Suponitsky and Arthur Vashurin

Molbank 2025, 2025(3), M2059; https://doi.org/10.3390/M2059 - 15 Sep 2025

Abstract

The synthesis and crystal structure of 4,11-dimethyl-2,13-di-m-tolyltribenzo[b,e,g][1,4]dioxocine-7,8-dicarbonitrile are reported. X-ray diffraction analysis reveals a rigid dioxocine core with m-tolyl substituents adopting torsional angles of 25–40°. The crystal packing is stabilized by C-H···N hydrogen bonds (2.6 Å) and π-π [...] Read more.

The synthesis and crystal structure of 4,11-dimethyl-2,13-di-m-tolyltribenzo[b,e,g][1,4]dioxocine-7,8-dicarbonitrile are reported. X-ray diffraction analysis reveals a rigid dioxocine core with m-tolyl substituents adopting torsional angles of 25–40°. The crystal packing is stabilized by C-H···N hydrogen bonds (2.6 Å) and π-π stacking interactions (3.4 Å) between dicarbonitrile groups, forming dimeric motifs. These structural insights provide a foundation for designing dioxocine-based functional materials. Full article

(This article belongs to the Section Structure Determination)

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9 pages, 1356 KB

Open AccessCommunication

Synthesis of (Camphor-3-yl)acetic Acid-Derived Pyrazoles

by Luka Ciber, Helena Brodnik, Nejc Petek, Franc Požgan, Jurij Svete, Bogdan Štefane and Uroš Grošelj

Molbank 2025, 2025(3), M2058; https://doi.org/10.3390/M2058 - 12 Sep 2025

Abstract

Two pyrazole derivatives were prepared in three steps from (camphor-3-yl)acetic acid. The pyrazole derivatives were fully characterized. The stereochemistry at the newly formed stereogenic center was confirmed by NOESY measurements and single crystal X-ray analysis. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Graphical abstract

9 pages, 1563 KB

Open AccessShort Note

5-(2-Methylsulfanylethyl)-3-prop-2-enyl-2-sulfanylideneimidazolidin-4-one

by Petar Stanić, Marko V. Rodić and Biljana Šmit

Molbank 2025, 2025(3), M2057; https://doi.org/10.3390/M2057 - 4 Sep 2025

Abstract

An amino acid-derived 2-thiohydantoin, 5-(2-methylsulfanylethyl)-3-prop-2-enyl-2-sulfanylideneimidazolidin-4-one, obtained from l-methionine, was synthesized in a two-step reaction protocol with allyl isothiocyanate. The compound was obtained in an 82% yield and was fully structurally characterized by NMR and IR spectroscopy. The crystal structure, molecular packing, and [...] Read more.

An amino acid-derived 2-thiohydantoin, 5-(2-methylsulfanylethyl)-3-prop-2-enyl-2-sulfanylideneimidazolidin-4-one, obtained from l-methionine, was synthesized in a two-step reaction protocol with allyl isothiocyanate. The compound was obtained in an 82% yield and was fully structurally characterized by NMR and IR spectroscopy. The crystal structure, molecular packing, and intermolecular interactions were characterized by X-ray diffraction analysis. Full article

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5 pages, 585 KB

Open AccessShort Note

3-([4-(Acetylamino)phenyl]methoxy-1-carbonyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic Acid

by Kathryn N. Mayeaux, Bailey N. Baxter, Hannah K. Lawley, Caleb N. Lopansri, Mary Helene Marmande, Lucy A. Orr and David C. Forbes

Molbank 2025, 2025(3), M2056; https://doi.org/10.3390/M2056 - 30 Aug 2025

Abstract

Overexpression of protein phosphatase 5 (PP5) is linked to tumor cell growth, making it a candidate for small-molecule drug therapy. Since the PP2A domain has been selectively inhibited using functionalized scaffolds that maximize contacts, a similar approach is proposed to work for PP5. [...] Read more.

Overexpression of protein phosphatase 5 (PP5) is linked to tumor cell growth, making it a candidate for small-molecule drug therapy. Since the PP2A domain has been selectively inhibited using functionalized scaffolds that maximize contacts, a similar approach is proposed to work for PP5. As cantharidin’s demethylated cousin, norcantharidin, is a potent but unselective phosphatase inhibitor that can be prepared in just two synthetic steps, the bicyclic scaffold holds promise as an attractive target upon functionalization. Our hypothesis targets PP5 selectivity through derivatives of norcantharidin with functionalized attachments for optimal active-site binding. The methodology offers a promising platform for developing PP5-selective anticancer therapeutics. The approach reported herein exploits anhydride reactivity to yield a carboxylic acid derivative as our next-generation inhibitor of PP5. The methodology offers groundwork for future optimization of norcantharidin-based drug candidates with improved tumor selectivity, potency, and synthetic feasibility. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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6 pages, 332 KB

Open AccessCommunication

Synthesis of Ethyl (S)-3-(1-Methyl-2-Oxo-Cyclohexyl)-2-Oxopropanoate Through Stereoselective Michael Addition

by Domenico C. M. Albanese and Nicoletta Gaggero

Molbank 2025, 2025(3), M2055; https://doi.org/10.3390/M2055 - 28 Aug 2025

Abstract

A practical four-step sequence for the synthesis of α,δ-dioxoesters with high enantiomeric excess was developed. It makes use of a regio- and stereoselective Michael addition of a chiral ketimine to ethyl 2-(phenylthio)-2-propenoate as a key transformation. The synthetic elaboration of the Michael adduct [...] Read more.

A practical four-step sequence for the synthesis of α,δ-dioxoesters with high enantiomeric excess was developed. It makes use of a regio- and stereoselective Michael addition of a chiral ketimine to ethyl 2-(phenylthio)-2-propenoate as a key transformation. The synthetic elaboration of the Michael adduct provides the new ethyl 3-(1-methyl-2-oxo-cyclohexyl)-2-oxopropanoate, bearing a quaternary stereocenter with 95% ee and high yield. Full article

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Graphical abstract

7 pages, 1218 KB

Open AccessCommunication

Synthesis of Novel Spiro-Isoxazolidine Derivatives of 9α-Hydroxyparthenolide

by Mohamed Zaki, Mohammed Loubidi and Sabine Berteina-Raboin

Molbank 2025, 2025(3), M2054; https://doi.org/10.3390/M2054 - 28 Aug 2025

Abstract

The 1,3-dipolar cycloaddition reaction was applied to 9α-hydroxyparthenolide, an important sesquiterpene component of Anvillea radiata that was extracted directly from plant material collected in Morocco. Several new spiro-isoxazolidine derivatives were generated on the B-ring of 9α-hydroxyparthenolide (α-methylene-γ-butyrolactone (1)) by 1,3-dipolar cycloaddition [...] Read more.

The 1,3-dipolar cycloaddition reaction was applied to 9α-hydroxyparthenolide, an important sesquiterpene component of Anvillea radiata that was extracted directly from plant material collected in Morocco. Several new spiro-isoxazolidine derivatives were generated on the B-ring of 9α-hydroxyparthenolide (α-methylene-γ-butyrolactone (1)) by 1,3-dipolar cycloaddition of its exocyclic double bond with various nitrones. These compounds were fully characterized by spectroscopic methods. Full article

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6 pages, 272 KB

Open AccessShort Note

1H,1H,7H-Dodecafluoroheptyl Pentafluorobenzoate

by Sofia S. Kascheeva, Anastasiya V. Lastovka, Andrey S. Vinogradov and Dmitriy A. Parkhomenko

Molbank 2025, 2025(3), M2053; https://doi.org/10.3390/M2053 - 27 Aug 2025

Abstract

Polyfluoroarenes are widely used in organic synthesis because they readily undergo nucleophilic substitution reactions. This reactivity prompted us to report the synthesis and spectroscopic characterization of a new compound, 1H,1H,7H-dodecafluoroheptyl pentafluorobenzoate, obtained via three different approaches starting from pentafluorobenzoic acid and 1H,1H,7H-dodecafluoroheptanol. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Scheme 1

5 pages, 590 KB

Open AccessCommunication

4,4′-Bis(1-(4-nitrophenyl)-2-(2,4,6-trinitrophenyl)hydrazineyl)-1,1′-biphenyl and Its Corresponding Stable Diradical

by Miron T. Caproiu and Petre Ionita

Molbank 2025, 2025(3), M2045; https://doi.org/10.3390/M2045 - 26 Aug 2025

Abstract

Starting with DPPH-diradical, the corresponding dinitro-derivative was obtained in a biphasic system using solid sodium nitrite and 15-crown-5 ether as the nitrating reagents. The new compound was characterized using 1H- and 13C-NMR, IR, and UV-Vis. After undergoing oxidation, a new stable diradical was [...] Read more.

Starting with DPPH-diradical, the corresponding dinitro-derivative was obtained in a biphasic system using solid sodium nitrite and 15-crown-5 ether as the nitrating reagents. The new compound was characterized using 1H- and 13C-NMR, IR, and UV-Vis. After undergoing oxidation, a new stable diradical was obtained, and this was characterized using ESR, IR, and UV-Vis. This process demonstrates that the well-known chemistry based on DPPH can be extended to DPPH-diradical. Full article

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6 pages, 938 KB

Open AccessShort Note

N-[(2H-1,3-benzodioxol-5-yl)methyl]-2-(2,2,2-trichloroacetamido)benzamide

by Plamen Penchev and Dimitar Stoitsov

Molbank 2025, 2025(3), M2052; https://doi.org/10.3390/M2052 - 25 Aug 2025

Abstract

The structure of N-[(2H-1,3-benzodioxol-5-yl)methyl]-2-(2,2,2-trichloroacetamido)benzamide was verified by using a combination of 1D and 2D NMR techniques. Fully assigned data from 1D NMR (¹H, ¹³C and DEPT 135) and 2D NMR (COSY, HMQC, HMBC) spectra was presented for [...] Read more.

The structure of N-[(2H-1,3-benzodioxol-5-yl)methyl]-2-(2,2,2-trichloroacetamido)benzamide was verified by using a combination of 1D and 2D NMR techniques. Fully assigned data from 1D NMR (¹H, ¹³C and DEPT 135) and 2D NMR (COSY, HMQC, HMBC) spectra was presented for the compound. The ¹H NMR spectrum of the ABX spin system in the benzodioxol moiety was simulated to predict the corresponding ⁿJ_HH coupling constants. The spectral assignments for the structure were supported by interpretive library search and HOSE predictions. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 625 KB

Open AccessCommunication

Three Hypoxanthine Derivatives from the Marine Cyanobacterium Okeania hirsuta

by Ryoya Kawabe, Botao Zhang, Ryuichi Watanabe, Hajime Uchida, Masayuki Satake and Hiroshi Nagai

Molbank 2025, 2025(3), M2051; https://doi.org/10.3390/M2051 - 21 Aug 2025

Abstract

Three novel hypoxanthine derivatives (1–3) were obtained from the Okinawan cyanobacterium Okeania hirsuta. The structures of these compounds were elucidated mainly based on the spectroscopic data, including 1D and 2D NMR, as well as high-resolution mass spectrometry. In [...] Read more.

Three novel hypoxanthine derivatives (1–3) were obtained from the Okinawan cyanobacterium Okeania hirsuta. The structures of these compounds were elucidated mainly based on the spectroscopic data, including 1D and 2D NMR, as well as high-resolution mass spectrometry. In particular, the amounts of obtained compounds 2 and 3 were only 200 μg and much less than 50 μg, respectively. Therefore, some carbons signals could not be observed on ¹³C NMR spectra of these compounds. However, the detailed analysis of HSQC and HMBC spectra allowed us to elucidate their structures. For NMR measurements of compound 3, it was found that using an 800 MHz NMR machine equipped with a cryogenic probe and acetic acid-d₄ as a solvent is essential. Compounds (1–3) were N-3′-carbonylbutyl group-connected hypoxanthines. Full article

(This article belongs to the Section Natural Product Chemistry)

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