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Molbank

Molbank is an international, peer-reviewed, open access journal comprised of a unique collection of one-compound-per-paper short notes on synthetic compounds and natural products published bimonthly online by MDPI.

Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
High Visibility: indexed within Scopus, ESCI (Web of Science), Reaxys, CAPlus / SciFinder, and other databases.
Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 14.7 days after submission; acceptance to publication is undertaken in 3.7 days (median values for papers published in this journal in the first half of 2026).
Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Journal Cluster of Chemical Reactions and Catalysis: Catalysts, Chemistry, Electrochem, Inorganics, Molecules, Organics, Oxygen, Photochem, Reactions, Sustainable Chemistry and Molbank.

Impact Factor: 0.3 (2025)

Imprint Information Journal Flyer Open Access ISSN: 1422-8599

Latest Articles

5 pages, 482 KB

Open AccessShort Note

(4aS,5R,6aS,7R,11aS,11bR)-9-(1-Benzyl-1H-benzo[d]imidazol-2-yl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl Acetate

by Jessica A. Perez-Rangel, Alejandro Islas-Jácome, Luis Chacón-García, Armando Talavera-Alemán and Carlos J. Cortés-García

Molbank 2026, 2026(4), M2206; https://doi.org/10.3390/M2206 - 17 Jul 2026

A new benzimidazole–6β-acetoxyvouacapane (4aS,5R,6aS,7R,11aS,11bR)-9-(1-benzyl-1H-benzo[d]imidazol-2-yl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl acetate was synthesized through the semisynthetic functionalization of the natural product 6β-acetoxyvouacapane. The target compound was obtained via a liquid-assisted mechanochemical condensation of [...] Read more.

A new benzimidazole–6β-acetoxyvouacapane (4aS,5R,6aS,7R,11aS,11bR)-9-(1-benzyl-1H-benzo[d]imidazol-2-yl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl acetate was synthesized through the semisynthetic functionalization of the natural product 6β-acetoxyvouacapane. The target compound was obtained via a liquid-assisted mechanochemical condensation of aldehyde 6β-acetoxyvouacapane with N-benzyl-o-phenylenediamine, followed by cyclization and oxidative aromatization under mild reaction conditions. The structure of the new compound was established by FT-IR, 1D and 2D NMR spectroscopy (COSY, HSQC, and HMBC), and high-resolution mass spectrometry (HRMS). Full article

(This article belongs to the Section Natural Product Chemistry)

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Graphical abstract

4 pages, 406 KB

Open AccessShort Note

1,5,9-tri(Phenylethynyl)-4,8,12-trioxaphosphangulene

by Kimiya Sukegawa, Masaki Yamamura and Tatsuya Nabeshima

Molbank 2026, 2026(4), M2205; https://doi.org/10.3390/M2205 - 16 Jul 2026

4,8,12-Trioxaphosphangulene is a bowl-shaped phosphorus-containing π-conjugated molecule whose molecular geometry is highly sensitive to the substituent attached to the phosphorus atom. Herein, we report the synthesis of a new tungsten pentacarbonyl complex of a chiral 4,8,12-trioxaphosphangulene bearing three phenylethynyl groups. The complex was [...] Read more.

4,8,12-Trioxaphosphangulene is a bowl-shaped phosphorus-containing π-conjugated molecule whose molecular geometry is highly sensitive to the substituent attached to the phosphorus atom. Herein, we report the synthesis of a new tungsten pentacarbonyl complex of a chiral 4,8,12-trioxaphosphangulene bearing three phenylethynyl groups. The complex was prepared by coordination of the phosphine center to an in situ generated W(CO)₅ fragment and was characterized by multinuclear NMR spectroscopy and elemental analysis. The NMR spectra revealed that the phosphangulene framework retains its threefold symmetry in solution. Comparison of the NMR parameters with those of a previously reported phosphangulene–tungsten complex indicates that incorporation of the phenylethynyl substituents has little effect on either the coordination environment around the phosphorus atom or the phosphine–tungsten interaction. These findings demonstrate that the characteristic bowl-shaped phosphangulene framework is preserved upon tungsten coordination despite π-extension of the molecular framework. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 358 KB

Open AccessCommunication

Synthesis of Azirinylammonium Salts via Alkylation of DABCO with 2-Halo-2H-azirines

by Maksim A. Valiarovskii, Alexander V. Vorob’ev, Anastasiya V. Agafonova and Mikhail S. Novikov

Molbank 2026, 2026(4), M2204; https://doi.org/10.3390/M2204 - 14 Jul 2026

Tertiary (2H-azirin-2-yl)ammonium salts were prepared from methyl 2-halo-3-aryl-2H-azirine-2-carboxylates and 1,4-diazabicyclo[2.2.2]octane in very good to excellent yields. Both iodide and bromide salts are stable enough in crystalline form to be stored in a freezer for up to several months. The [...] Read more.

Tertiary (2H-azirin-2-yl)ammonium salts were prepared from methyl 2-halo-3-aryl-2H-azirine-2-carboxylates and 1,4-diazabicyclo[2.2.2]octane in very good to excellent yields. Both iodide and bromide salts are stable enough in crystalline form to be stored in a freezer for up to several months. The structures of the obtained salts were confirmed by NMR spectroscopy and HRMS. Full article

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

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Graphical abstract

9 pages, 1489 KB

Open AccessShort Note

10-(3,5-Di-tert-butylphenyl)-9-methylacridinium Tetrafluoroborate

by Yuki Itabashi and Kei Ohkubo

Molbank 2026, 2026(4), M2203; https://doi.org/10.3390/M2203 - 14 Jul 2026

A 9-methylacridinium salt, 10-(3,5-di-tert-butylphenyl)-9-methylacridin-10-ium tetrafluoroborate (2), was synthesized from the corresponding acridone by treatment with methylmagnesium bromide followed by tetrafluoroboric acid. Compound 2 was obtained as a yellow solid in 95% yield and characterized by NMR spectroscopy and high-resolution [...] Read more.

A 9-methylacridinium salt, 10-(3,5-di-tert-butylphenyl)-9-methylacridin-10-ium tetrafluoroborate (2), was synthesized from the corresponding acridone by treatment with methylmagnesium bromide followed by tetrafluoroboric acid. Compound 2 was obtained as a yellow solid in 95% yield and characterized by NMR spectroscopy and high-resolution mass spectrometry. Electrochemical measurements revealed irreversible reduction behavior, with a reduction potential of −0.52 V vs. SCE determined by second-harmonic alternating-current voltammetry. Compound 2 exhibited absorption extending into the visible region and fluorescence at 492 nm with a lifetime of 4.6 ns. Unlike the previously reported 9-mesityl analogue, compound 2 was fluorescent, a difference that may reflect the absence of the high-lying donor orbital associated with the 9-mesityl group. Its singlet excited-state reduction potential was estimated to be +2.21 V vs. SCE, indicating substantial photooxidizing ability. DFT and TD-DFT calculations provided complementary insight into its frontier molecular orbital distributions and principal electronic transitions. These findings highlight the influence of the 9-substituent on the electronic and emissive properties of acridinium-based photoactive molecules. Full article

(This article belongs to the Collection Molecules from Catalytic Processes)

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8 pages, 2161 KB

Open AccessShort Note

(5S)-5-[(2-(5-Bromo-2-methoxyphenyl)quinazolin-4-yl Amino)methyl]-3-(3-fluoro-4-morpholinophenyl)oxazolidin-2-one

by Mingguang Zhang, Siyu Hao, Baiyang Mao and Yongxu Piao

Molbank 2026, 2026(4), M2202; https://doi.org/10.3390/M2202 - 10 Jul 2026

4-aminoquinazoline derivatives exhibit unique physiological activities, including antitumor, anti-inflammatory, and antibacterial biological activities. Afatinib (BIBW-2992), the representative tyrosine kinase inhibitor, has been developed for the treatment of non-small cell lung cancer. Following our expanded medical chemistry research program, we report a novel 4-aminoquinazoline [...] Read more.

4-aminoquinazoline derivatives exhibit unique physiological activities, including antitumor, anti-inflammatory, and antibacterial biological activities. Afatinib (BIBW-2992), the representative tyrosine kinase inhibitor, has been developed for the treatment of non-small cell lung cancer. Following our expanded medical chemistry research program, we report a novel 4-aminoquinazoline derivative named JSLN-P (1), (5S)-5-[(2-(5-bromo-2-methoxyphenyl) quinazolin-4-ylamino)methyl]-3-(3-fluoro-4-morpholino phenyl) oxazolidin-2-one, aimed for developing new drugs with antiglioma properties. The title compound JSLN-P (1) was successfully synthesized by amination approaches following benzylamination and oxazolone cyclization, further condensation with 4-(4-bromo-2-fluorophenyl) morpholine, reduction in debenzylation and halogenated amination of quinazolin. The structure of JSLN-P (1) was confirmed by ¹H and ¹³C nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). Full article

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

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4 pages, 234 KB

Open AccessShort Note

(E)-4-(3-Oxo-3-(2-oxo-2,3-dihydrobenzo[d]oxazol-6-yl)prop-1-en-1-yl)benzaldehyde

by Yordanka B. Ivanova, Daniel Y. Yordanov and Ognyan I. Petrov

Molbank 2026, 2026(4), M2201; https://doi.org/10.3390/M2201 - 9 Jul 2026

In the present study, (E)-4-(3-oxo-3-(2-oxo-2,3-dihydrobenzo[d]oxazol-6-yl)prop-1-en-1-yl)benzaldehyde (2) was synthesized via a base-catalyzed Claisen–Schmidt condensation of 6-acetylbenzo[d]oxazol-2(3H)-one (1) and terephthalaldehyde and characterized by spectroscopic methods. Full article

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Scheme 1

5 pages, 569 KB

Open AccessShort Note

N-(4-fluorobenzyl)-N′-(4-fluorobenzylidene)-4-methylbenzenesulfonohydrazide

by Lei Gao, Li Xu, Zheng Zhang, Jinchang Zhang, Diangang Bai, Xiangrong Wang and Yue Zhang

Molbank 2026, 2026(4), M2200; https://doi.org/10.3390/M2200 - 6 Jul 2026

Herein, we present the synthesis of N-(4-fluorobenzyl)-N’-(4-fluorobenzylidene)-4-methylbenzenesulfonohydrazide. The compound has been thoroughly characterized through melting-point determination, ¹H and ¹³C NMR spectroscopy and mass spectrometry. The structure was unequivocally determined by X-ray analysis. The comprehensive analytical data obtained from [...] Read more.

Herein, we present the synthesis of N-(4-fluorobenzyl)-N’-(4-fluorobenzylidene)-4-methylbenzenesulfonohydrazide. The compound has been thoroughly characterized through melting-point determination, ¹H and ¹³C NMR spectroscopy and mass spectrometry. The structure was unequivocally determined by X-ray analysis. The comprehensive analytical data obtained from these techniques confirm the successful preparation and structural integrity of the newly synthesized molecule. Full article

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7 pages, 1974 KB

Open AccessShort Note

Methyl 3-(Propan-2-ylidene)-3a,9a-dihydro-3H-cyclopenta[a]azulene-9-carboxylate

by Miku Yoshida, Masafumi Yasunami, Ryuta Sekiguchi, Shunji Ito and Taku Shoji

Molbank 2026, 2026(4), M2199; https://doi.org/10.3390/M2199 - 3 Jul 2026

Methyl 3-(propan-2-ylidene)-3a,9a-dihydro-3H-cyclopenta[a]azulene-9-carboxylate (2) was synthesized in moderate yield via an [8 + 2] cycloaddition of methyl 2-oxo-2H-cyclohepta[b]furan-3-carboxylate (1) with 6,6-dimethylfulvene. The resulting compound was characterized by ¹H and ¹³C NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray diffraction analysis. Full article

(This article belongs to the Section Structure Determination)

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8 pages, 2007 KB

Open AccessCommunication

Synthesis of 8-Bromo-2-(chloromethyl)-6-methoxy-5-nitroimidazo[1,2-a]pyridine and 8-Bromo-2-(chloromethyl)-6-methoxy-3,5-dinitroimidazo[1,2-a]pyridine

by Inès Jacquet, Romain Paoli-Lombardo, Caroline Castera-Ducros, Patrice Vanelle and Nicolas Primas

Molbank 2026, 2026(4), M2198; https://doi.org/10.3390/M2198 - 3 Jul 2026

A novel synthetic approach was developed to synthesize 6-methoxy substituted imidazo[1,2-a]pyridine derivatives, with the objective of obtaining analogs of previously identified antileishmanial hit compounds. The nitration of 8-bromo-2-(chloromethyl)-6-methoxyimidazo[1,2-a]pyridine under classical nitric acid/sulfuric acid conditions resulted in selective nitration at [...] Read more.

A novel synthetic approach was developed to synthesize 6-methoxy substituted imidazo[1,2-a]pyridine derivatives, with the objective of obtaining analogs of previously identified antileishmanial hit compounds. The nitration of 8-bromo-2-(chloromethyl)-6-methoxyimidazo[1,2-a]pyridine under classical nitric acid/sulfuric acid conditions resulted in selective nitration at position 5 and the corresponding 3,5-dinitrated derivative. The structures of these compounds were established through a combination of experimental methods, including ¹H and ¹³C NMR, HRMS, HSQC, and HMBC experiments. These structural determinations were subsequently confirmed through single-crystal X-ray diffraction. These compounds represent the first examples of 5-nitrated and 3,5-dinitrated 6-methoxyimidazo[1,2-a]pyridines. Full article

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8 pages, 1494 KB

Open AccessShort Note

3-(4-Hydroxynaphthalen-1-yl)-3-(1-hydroxynaphthalen-2-yl)isobenzofuran-1(3H)-one

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

Molbank 2026, 2026(4), M2195; https://doi.org/10.3390/M2195 - 1 Jul 2026

3-(4-hydroxynaphthalen-1-yl)-3-(1-hydroxynaphthalen-2-yl)isobenzofuran-1(3H)-one is a previously unknown derivative of the well-known acid/base indicator naphtholphthalein. 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 data, IR spectroscopy data, [...] Read more.

3-(4-hydroxynaphthalen-1-yl)-3-(1-hydroxynaphthalen-2-yl)isobenzofuran-1(3H)-one is a previously unknown derivative of the well-known acid/base indicator naphtholphthalein. 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 data, IR spectroscopy data, and mass spectrometry data are provided. Full article

(This article belongs to the Section Structure Determination)

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9 pages, 1149 KB

Open AccessCommunication

The Crystal Structure of N,N′-bis(3,5-di-tert-Butylsalicylidene)propane-1,2-diamine)-oxidovanadium(IV) and Its Parent Ligand

by Kirsten S. Graham, Aidan P. McKay, David B. Cordes and Brian A. Chalmers

Molbank 2026, 2026(4), M2196; https://doi.org/10.3390/M2196 - 1 Jul 2026

The asymmetric salen ligand N,N′-bis(3,5-di-tert-butylsalicylidene)propane-1,2-diamine (1) with a single chiral center and its vanadyl complex (2) have been prepared and characterized by single-crystal X-ray diffraction. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 459 KB

Open AccessShort Note

Olean-18α-19β,28-epoxy-3β-benzoate

by Xiqiang Gao, Jung Hoon Park, Bohua Lu, Jinxing Zhai, Xiaoyi Sun, Yuanhui Wang, Lak Shin Jeong and Qiang Wang

Molbank 2026, 2026(4), M2197; https://doi.org/10.3390/M2197 - 1 Jul 2026

Allobetulin 3-benzoate was obtained as an unexpected byproduct during the acid-mediated protection–deprotection of betulin. Single-crystal X-ray diffraction analysis shows that it crystallizes in the triclinic space group P1 with Z = 2 and contains two crystallographically independent molecules in the asymmetric unit. [...] Read more.

Allobetulin 3-benzoate was obtained as an unexpected byproduct during the acid-mediated protection–deprotection of betulin. Single-crystal X-ray diffraction analysis shows that it crystallizes in the triclinic space group P1 with Z = 2 and contains two crystallographically independent molecules in the asymmetric unit. Compared with allobetulin (P2₁, Z = 4) and allobetulin 3-acetate (C2, Z = 4), the benzoyl substitution at C-3 induces distinct molecular packing and intermolecular interaction patterns, highlighting the influence of steric and electronic effects on crystal architecture. Full article

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7 pages, 477 KB

Open AccessShort Note

Methyl (S)-3-((1r*,3R*)-3-((1H-indol-3-yl)methyl)cyclobutane-1-carboxamido)-2-(phenylsulfonamido)propanoate

by Helen M. Sheldrake

Molbank 2026, 2026(4), M2194; https://doi.org/10.3390/M2194 - 1 Jul 2026

The cyclobutane ring has attractive properties as a scaffold in medicinal chemistry but is underused, potentially due to the limited methods available for synthesising highly functionalised cyclobutanes. This short note describes the synthesis of the 1,3-cis disubstituted cyclobutane, methyl (S)-3-((1 [...] Read more.

The cyclobutane ring has attractive properties as a scaffold in medicinal chemistry but is underused, potentially due to the limited methods available for synthesising highly functionalised cyclobutanes. This short note describes the synthesis of the 1,3-cis disubstituted cyclobutane, methyl (S)-3-((1r*,3R*)-3-((1H-indol-3-yl)methyl)cyclobutane-1-carboxamido)-2-(phenylsulfonamido)propanoate using a one-pot thermal stepwise cycloaddition reaction and its characterisation by NMR spectroscopy and HRMS. Full article

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

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4 pages, 418 KB

Open AccessShort Note

1α-Methoxy-3-oxo-8α-hydroxy-10αH-eremophila-7(11)-en-12,8β-olide from Ligularia fischeri

by Xiangrong Zhang, Dingkuo Liu, Fang Liu, Cheng Yang, Jingjing Gao and Chunfeng Xie

Molbank 2026, 2026(3), M2193; https://doi.org/10.3390/M2193 - 12 Jun 2026

One unreported eremophilane sesquiterpenoid, 1α-methoxy-3-oxo-8α-hydroxy-10αH- eremophila-7(11)-en-12,8β-olide (1), was isolated from Ligularia fischeri. The structure of 1 was identified by detailed 1D and 2D NMR and HRMS analyses. Full article

(This article belongs to the Section Natural Product Chemistry)

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1 pages, 133 KB

Open AccessCorrection

Correction: Chen et al. N-(2,5-Difluorobenzylidene)-1-(2,5-difluorobenzyl)methanimine. Molbank 2026, 2026, M2174

by Tiffany L. Chen, Manisha Sharma and Nicholas E. Leadbeater

Molbank 2026, 2026(3), M2190; https://doi.org/10.3390/M2190 - 9 Jun 2026

There was an error in the original publication [...] Full article

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

7 pages, 804 KB

Open AccessShort Note

Uranyl Complex of 1,3-bis(ditertbutylphosphinoxidomethyl)benzene

by Maha M. Alotaibi, Md Abdul Goni, Eric Reinheimer and Tasneem A. Siddiquee

Molbank 2026, 2026(3), M2191; https://doi.org/10.3390/M2191 - 9 Jun 2026

This short note presents a new molecule isolated and characterized from the reaction of uranyl nitrate with the PCP-type pincer ligand 1,3-bis(ditertbutylphosphinomethyl)benzene in the presence of UV light under ambient conditions. The new dinuclear uranyl-PCP complex was characterized by using FT-IR spectroscopy and [...] Read more.

This short note presents a new molecule isolated and characterized from the reaction of uranyl nitrate with the PCP-type pincer ligand 1,3-bis(ditertbutylphosphinomethyl)benzene in the presence of UV light under ambient conditions. The new dinuclear uranyl-PCP complex was characterized by using FT-IR spectroscopy and single-crystal X-ray crystallography. As revealed by the crystal structure, the new complex had oxygen atoms coordinating from the phosphinoxides that were oxidized under ambient conditions. Each uranium atom of this dinuclear complex was found to exhibit pentagonal bipyramidal coordination geometry. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

6 pages, 1063 KB

Open AccessShort Note

4-Methyl-N-(4-methylbenzyl)-N’-(4-methylbenzylidene) benzenesulfonohydrazide

by Yue Zhang, Xiangrong Wang, Zhihan Liu, Zheng Zhang, Xiaoxu Tan and Lei Gao

Molbank 2026, 2026(3), M2192; https://doi.org/10.3390/M2192 - 9 Jun 2026

4-Methyl-N-(4-methylbenzyl)-N’-(4-methylbenzylidene)benzenesulfonohydrazide was synthesized via N-alkylation. The compound was characterized by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Its molecular structure was unambiguously established by single-crystal X-ray diffraction analysis. The comprehensive spectral and crystallographic data conclusively verify [...] Read more.

4-Methyl-N-(4-methylbenzyl)-N’-(4-methylbenzylidene)benzenesulfonohydrazide was synthesized via N-alkylation. The compound was characterized by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Its molecular structure was unambiguously established by single-crystal X-ray diffraction analysis. The comprehensive spectral and crystallographic data conclusively verify the successful synthesis and structural integrity of this newly prepared compound. Full article

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12 pages, 1728 KB

Open AccessShort Note

2-Chloro-4,5,6,7-tetrafluoro-2-(methylthio)-1H-indene-1,3(2H)-dione

by Anastasia R. Kovrizhina and Andrei I. Khlebnikov

Molbank 2026, 2026(3), M2189; https://doi.org/10.3390/M2189 - 8 Jun 2026

We report the synthesis of the new compound 2-chloro-4,5,6,7-tetrafluoro-2-(methylthio)-1H-indene-1,3(2H)-dione (Compound 3), which presents an important type of fluoro-containing heterocycles and is a useful intermediate product in organic synthesis. The structure of the compound was confirmed by the NMR [...] Read more.

We report the synthesis of the new compound 2-chloro-4,5,6,7-tetrafluoro-2-(methylthio)-1H-indene-1,3(2H)-dione (Compound 3), which presents an important type of fluoro-containing heterocycles and is a useful intermediate product in organic synthesis. The structure of the compound was confirmed by the NMR and elemental analysis. A quantum-chemical comparison (DFT) of 2-chloro-2-(methylthio)-1H-indene-1,3(2H)-dione (with C-H bonds, compound 4) and its 4,5,6,7-tetrafluoro derivative (with C-F bonds, compound 3) at the M06-2X/6-311++G(d,p) level in THF showed that the introduction of four fluorine atoms into the benzene ring causes a systematic shortening of the C=O, C-Cl, and C-C bonds of the five-membered ring, as well as an almost twofold decrease in the dipole moment. Replacing hydrogen with fluorine leads to a simultaneous stabilization of the frontier orbitals and a narrowing of the HOMO–LUMO energy gap, while the electron affinity increases by 0.39 eV and the electrophilicity index increases from 2.77 to 3.24 eV, making compound 3 a strong electrophile. Analysis of donor–acceptor interactions (NBOs) and condensed Fukui indices confirms that perfluorination selectively increases the electrophilicity of the sp³-carbon center of C-Cl, making it more susceptible to nucleophilic attack. At the same time, the isodesmic reaction with 1,2,4,5-tetrafluorobenzene yields a positive free energy change (ΔG = +13.4 kcal/mol), indicating that the increased reactivity of compound 3 is kinetic rather than thermodynamic in nature. The synthesized 1,3-indandione derivative thus represents a promising precursor for tetrafluoroninhydrin and can be considered a biologically active compound. Thus, perfluorination of the indandione skeleton is an effective tool for targeted enhancement of electrophilic properties without fundamentally changing the geometry of the molecule, which opens up prospects for the design of new highly reactive reagents. Full article

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

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6 pages, 681 KB

Open AccessShort Note

3-(Methylthio)-1-[(4-nitrophenyl)sulfonyl]-1H-1,2,4-triazol-5-amine

by Diana Becerra, Mario A. Macías and Juan-Carlos Castillo

Molbank 2026, 2026(3), M2186; https://doi.org/10.3390/M2186 - 5 Jun 2026

We report a highly chemoselective N-sulfonylation of 3-(methylthio)-1H-1,2,4-triazol-5-amine with 4-nitrobenzenesulfonyl chloride promoted by N,N-diisopropylethylamine in acetonitrile under mild conditions. This transformation selectively affords N-(4-nitrophenyl)sulfonylation at the N1 position of the 1,2,4-triazole ring over the exocyclic amine [...] Read more.

We report a highly chemoselective N-sulfonylation of 3-(methylthio)-1H-1,2,4-triazol-5-amine with 4-nitrobenzenesulfonyl chloride promoted by N,N-diisopropylethylamine in acetonitrile under mild conditions. This transformation selectively affords N-(4-nitrophenyl)sulfonylation at the N1 position of the 1,2,4-triazole ring over the exocyclic amine functionality. The product was fully characterized by IR, 1D and 2D NMR spectroscopy, as well as high-resolution mass spectrometry, unequivocally confirming its molecular structure. Full article

(This article belongs to the Collection Heterocycle Reactions)

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10 pages, 2778 KB

Open AccessShort Note

2-((((R)-3-(((9E,17Z)-18-Bromooctadeca-9,17-dien-7,15-diynoyl)oxy)-2-hydroxypropoxy)(hydroxy)phosphoryl)oxy)-N,N,N-trimethylethan-1-aminium

by Abdu Al Nashrey, Emmanuel T. Oluwabusola, Hussin D. Almalki, Gagan Preet, Dawrin Pech-Puch, Abel M. Forero, Jaime Rodriguez, Rainer Ebel and Marcel Jaspars

Molbank 2026, 2026(3), M2188; https://doi.org/10.3390/M2188 - 5 Jun 2026

The Saudi Arabian Red Sea has been a focus of ongoing scientific exploration due to its extensive, largely untapped marine biodiversity, particularly marine sponges. Marine sponges have long been recognised as a valuable source of unique compounds. In this study, we isolated a [...] Read more.

The Saudi Arabian Red Sea has been a focus of ongoing scientific exploration due to its extensive, largely untapped marine biodiversity, particularly marine sponges. Marine sponges have long been recognised as a valuable source of unique compounds. In this study, we isolated a new brominated compound (1) from the marine sponge Aiolochroia crassa, collected from the Saudi Arabian Sea, using chromatographic analyses. Molecular networking analysis revealed the presence of brominated molecules in the extract. The identified compound belongs to a class of phosphatidylcholine derivatives. The structure of compound 1 was elucidated using 1D and 2D NMR spectroscopy and high-resolution ESI-Q-TOF mass spectrometry. Further structure confirmation studies were performed using MS/MS fragmentation analysis and DFT calculations for the ¹H and ¹³C NMR chemical shifts. This is the first report of 1 from this species of marine sponges. Full article

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Special Issue in Molbank

Carbonylation Chemistry in the Synthesis of High Value Added Compounds Guest Editors: Bartolo Gabriele, Raffaella Mancuso
Deadline: 30 November 2026

Topical Collections

Topical Collection in Molbank

Molecules from Catalytic Processes Collection Editor: Nicola Della Ca’

Topical Collection in Molbank

Heterocycle Reactions Collection Editor: Fawaz Aldabbagh

Topical Collection in Molbank

Molecules from Side Reactions Collection Editor: Stefano D’Errico

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