Molbank

6 pages, 803 KB

Open AccessCommunication

Synthesis and Characteristics of New 3-(Dichloromethyl)-2-nitro-6,7-dihydro-1-benzofuran-4(5H)-ones

by Ilia A. Pilipenko, Olga Yu. Ozerova, Oleg P. Demidov, Ruslan I. Baichurin, Oussama A. Mammeri and Sergey V. Makarenko

Molbank 2026, 2026(1), M2134; https://doi.org/10.3390/M2134 - 6 Feb 2026

Abstract

The previously unknown compounds—3-(dichloromethyl)-2-nitro-6,7-dihydro-1-benzofuran-4(5H)-ones—have been synthesized and structurally characterized via single-crystal X-ray diffraction, ¹H, ¹³C–{¹H}, ¹H–¹³C HMQC and ¹H–¹³C HMBC NMR spectroscopy, IR, and UV spectroscopy. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

9 pages, 2244 KB

Open AccessShort Note

2-Iodopyridin-3-yl acetate

by Mihaela Cristea, Sergiu Shova, Marcel Mirel Popa and Florea Dumitrascu

Molbank 2026, 2026(1), M2135; https://doi.org/10.3390/M2135 - 6 Feb 2026

Abstract

The title compound 2-iodopyridin-3-yl acetate was obtained by acetylation of the OH group of 2-iodo-3-hydroxypyridine. Knowing that the hydroxyl group, as a strong H-bond donor in halogenated hydroxypyridines, usually directs supramolecular packing and might enforce possible halogen–halogen contacts, we crystallized 2-iodo-3-acetoxypyridine with the [...] Read more.

The title compound 2-iodopyridin-3-yl acetate was obtained by acetylation of the OH group of 2-iodo-3-hydroxypyridine. Knowing that the hydroxyl group, as a strong H-bond donor in halogenated hydroxypyridines, usually directs supramolecular packing and might enforce possible halogen–halogen contacts, we crystallized 2-iodo-3-acetoxypyridine with the aim of disrupting the most important H-bond donor and assessing the propensity of the iodine for halogen bond formation. Indeed, in the compound 2-iodopyridin-3-yl acetate, the crystal packing is characterized by infinite 3D chains bonded through I···O=C and C-H···I contacts between adjacent molecules. These chains are interconnected by weak C-H···O contacts, implying the presence of oxygen in the ester. The I···H contact with the C-H axis perpendicular to the electron belt of the iodine atom can enhance the σ-hole of the iodine and act cooperatively in crystal cohesion. No halogen–halogen contacts were present. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

8 pages, 1859 KB

Open AccessShort Note

2,3,4,6-Tetra(9H-carbazol-9-yl)benzonitrile

by Qing-Qing Wan and Zhi-Cheng Fu

Molbank 2026, 2026(1), M2136; https://doi.org/10.3390/M2136 - 6 Feb 2026

Abstract

Here, we synthesized 2,3,4,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzHPN) via visible-light-driven photocatalytic monodecyanation using the versatile metal-free catalyst 4CzIPN. Characterized by NMR, IR, X-ray diffraction, and DFT calculations, it features a 3.49 eV HOMO-LUMO gap and shows blue-shifted absorption/emission, emerging as a promising advanced metal-free [...] Read more.

Here, we synthesized 2,3,4,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzHPN) via visible-light-driven photocatalytic monodecyanation using the versatile metal-free catalyst 4CzIPN. Characterized by NMR, IR, X-ray diffraction, and DFT calculations, it features a 3.49 eV HOMO-LUMO gap and shows blue-shifted absorption/emission, emerging as a promising advanced metal-free photoredox catalyst. Full article

(This article belongs to the Section Structure Determination)

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5 pages, 256 KB

Open AccessShort Note

2-(3′,5′-Bis((dodecyloxy)carbonyl)-2′,6′-dimethyl-1′,4′-dihydro-[3,4′-bipyridin]-1-ium-1-yl)-1,3-dioxo-2,3-dihydro-1H-inden-2-ide

by Mara Plotniece, Krista Arule, Karlis Pajuste, Aiva Plotniece and Arkadij Sobolev

Molbank 2026, 2026(1), M2133; https://doi.org/10.3390/M2133 - 4 Feb 2026

Abstract

Indane-1,3-dione and 1,4-dihydropyridine (1,4-DHP) scaffolds are of significant interest in medicinal chemistry. Herein, we report the synthesis characterization of a new lipid-like indane-1,3-dione–1,4-DHP betaine, 2-(3′,5′-bis((dodecyloxy)carbonyl)-2′,6′-dimethyl-1′,4′-dihydro-[3,4′-bipyridin]-1-ium-1-yl)-1,3-dioxo-2,3-dihydro-1H-inden-2-ide (3). Compound 3 was synthesized from 2,2-dicyanomethylideneindan-1,3-dione (1) oxide and a didodecyl-substituted [...] Read more.

Indane-1,3-dione and 1,4-dihydropyridine (1,4-DHP) scaffolds are of significant interest in medicinal chemistry. Herein, we report the synthesis characterization of a new lipid-like indane-1,3-dione–1,4-DHP betaine, 2-(3′,5′-bis((dodecyloxy)carbonyl)-2′,6′-dimethyl-1′,4′-dihydro-[3,4′-bipyridin]-1-ium-1-yl)-1,3-dioxo-2,3-dihydro-1H-inden-2-ide (3). Compound 3 was synthesized from 2,2-dicyanomethylideneindan-1,3-dione (1) oxide and a didodecyl-substituted 1,4-DHP derivative 2 and characterized by UV–Vis spectroscopy, ¹H-NMR, ¹³C-NMR, and HRMS. The obtained results demonstrate a promising strategy for the design of delivery agents, exploiting the lipid-like properties of the synthesized betaine. Full article

(This article belongs to the Collection Heterocycle Reactions)

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Scheme 1

6 pages, 307 KB

Open AccessShort Note

N-(4-Methoxyphenethyl)-2-propylpentanamide

by Diyana Dimitrova, Tsvetelina Marinova, Reni Bozhanova, Iliyan Ivanov, Dimitar Bojilov, Gabriel Marc and Stanimir Manolov

Molbank 2026, 2026(1), M2132; https://doi.org/10.3390/M2132 - 4 Feb 2026

Abstract

Herein, we report the mechanochemical synthesis of a novel hybrid molecule, N-(4-methoxyphenethyl)-2-propylpentanamide. This solvent-minimized synthesis aligns with the principles of Green Chemistry and exemplifies the emerging paradigm of medicinal mechanochemistry, offering an efficient, sustainable route to pharmaceutically relevant amides. The newly synthesized [...] Read more.

Herein, we report the mechanochemical synthesis of a novel hybrid molecule, N-(4-methoxyphenethyl)-2-propylpentanamide. This solvent-minimized synthesis aligns with the principles of Green Chemistry and exemplifies the emerging paradigm of medicinal mechanochemistry, offering an efficient, sustainable route to pharmaceutically relevant amides. The newly synthesized compound was fully characterized by melting point determination, ¹H and ¹³C NMR spectroscopy, infrared (IR) spectroscopy, and mass spectrometry. Full article

(This article belongs to the Section Structure Determination)

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11 pages, 3476 KB

Open AccessCommunication

Molecular Structure of the Monohydrate Hydrochloride Salt of the Antimalarial Drug Chloroquine

by Silvia Rizzato and Massimo Moret

Molbank 2026, 2026(1), M2131; https://doi.org/10.3390/M2131 - 3 Feb 2026

Abstract

We report the crystallization and single-crystal X-ray analysis of the monohydrate hydrochloride salt of chloroquine(CQ), abbreviated CQHCl·H₂O, an antimalarial drug with the formula C₁₈H₂₆ClN₃. The crystal structure reveals a well-defined supramolecular architecture stabilized by [...] Read more.

We report the crystallization and single-crystal X-ray analysis of the monohydrate hydrochloride salt of chloroquine(CQ), abbreviated CQHCl·H₂O, an antimalarial drug with the formula C₁₈H₂₆ClN₃. The crystal structure reveals a well-defined supramolecular architecture stabilized by an extensive hydrogen-bonding network involving CQH⁺ cations, chloride anions, and water molecules. Notably, this study provides the first crystallographic characterization of a monoprotonated chloroquine salt. Additionally, our findings demonstrate the feasibility of isolating pseudo-polymorphic forms of a commercially available CQ salt via heterogeneous crystallization. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

8 pages, 1098 KB

Open AccessShort Note

(2RS,3aRS,9aRS)-3a-Methyl-2-phenyl-3,3a,9,9a-tetrahydro-1H-benzo[f]indol-4(2H)-one Hydrobromide

by Denis A. Tiunov, Victor A. Tafeenko and Alexander V. Kurkin

Molbank 2026, 2026(1), M2130; https://doi.org/10.3390/M2130 - 2 Feb 2026

Abstract

(2RS,3aRS,9aRS)-3a-methyl-2-phenyl-3,3a,9,9a-tetrahydro-1H-benzo[f]indol-4(2H)-one hydrobromide was first synthesized via a tandem aza-Cope rearrangement and Mannich reaction from (1RS,2SR)-2-amino-1-(prop-1-en-2-yl)-2,3-dihydro-1H-inden-1-ol, which, in turn, was obtained in four steps from commercially available 2,3-dihydro-1 [...] Read more.

(2RS,3aRS,9aRS)-3a-methyl-2-phenyl-3,3a,9,9a-tetrahydro-1H-benzo[f]indol-4(2H)-one hydrobromide was first synthesized via a tandem aza-Cope rearrangement and Mannich reaction from (1RS,2SR)-2-amino-1-(prop-1-en-2-yl)-2,3-dihydro-1H-inden-1-ol, which, in turn, was obtained in four steps from commercially available 2,3-dihydro-1H-inden-1-one. The molecular and crystal structure features of the new compounds were characterized using NMR spectroscopy (¹H, ¹³C spectra). Full article

(This article belongs to the Collection Heterocycle Reactions)

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9 pages, 1676 KB

Open AccessCommunication

Synthesis of 1-(Naphthalen-2-yl)-3-(3-(triethoxysilyl)propyl)urea and Determination of Its Crystal Structure

by Abderrahim Khatyr, Isabelle Jourdain, Michael Knorr, Carsten Strohmann and Tobias Schrimpf

Molbank 2026, 2026(1), M2129; https://doi.org/10.3390/M2129 - 28 Jan 2026

Abstract

The addition of 3-isocyanatopropyltriethoxysilane and 2-aminonaphthalene in THF affords the title compound 1-(naphthalen-2-yl)-3-(3-(triethoxysilyl)propyl)urea 1. A determination of the crystal structure of this naphthyl urea reveals the occurrence of strong intermolecular N-H···O hydrogen bonds, giving rise to a 1D supramolecular ribbon, whose interactions [...] Read more.

The addition of 3-isocyanatopropyltriethoxysilane and 2-aminonaphthalene in THF affords the title compound 1-(naphthalen-2-yl)-3-(3-(triethoxysilyl)propyl)urea 1. A determination of the crystal structure of this naphthyl urea reveals the occurrence of strong intermolecular N-H···O hydrogen bonds, giving rise to a 1D supramolecular ribbon, whose interactions have also been assessed by a Hirshfeld surface analysis. The propensity of 1 to sense halide ions by intramolecular trapping through N-H···Hal bonding was also investigated by UV-vis spectroscopy and fluorescence measurements. Full article

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4 pages, 512 KB

Open AccessShort Note

2-((6,7-Dimethoxy-4-oxo-3-(4-(trifluoromethyl)phenethyl)-3,4-dihydroquinazolin-2-yl)thio)-N-(4-ethylphenyl)butanamide

by Young Hee Lee and Jae-Kyung Jung

Molbank 2026, 2026(1), M2128; https://doi.org/10.3390/M2128 - 26 Jan 2026

Abstract

2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the representative CHI3L1 inhibitor, has interesting biological activities, including anti-cancer and anti-inflammatory effects on neuroinflammation. Following our hit-to-lead program, we report the most active novel derivative, named CBJL-025, 2-((6,7-dimethoxy-4-oxo-3-(4-(trifluoromethyl)phenethyl)-3,4-dihydroquinazolin-2-yl)thio)-N-(4-ethylphenyl)butanamide. The title compound, CBJL-025, was successfully synthesized by S [...] Read more.

2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the representative CHI3L1 inhibitor, has interesting biological activities, including anti-cancer and anti-inflammatory effects on neuroinflammation. Following our hit-to-lead program, we report the most active novel derivative, named CBJL-025, 2-((6,7-dimethoxy-4-oxo-3-(4-(trifluoromethyl)phenethyl)-3,4-dihydroquinazolin-2-yl)thio)-N-(4-ethylphenyl)butanamide. The title compound, CBJL-025, was successfully synthesized by S-alkylation of the p-trifluoromethyl phenethyl group possessing quinazoline and the corresponding bromide. The structure of CBJL-025 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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6 pages, 399 KB

Open AccessShort Note

Ethyl 2-(2-((6-Methyl-4-oxo-4H-chromen-3-yl)methylene)hydrazineyl)thiazole-4-carboxylate

by Adriana Grozav, Cristina Azarov, Gabriel Marc, Adrian Pîrnău, Stanimir Manolov, Ovidiu Oniga and Ovidiu Crișan

Molbank 2026, 2026(1), M2127; https://doi.org/10.3390/M2127 - 22 Jan 2026

Abstract

This study presents the synthesis of a new compound, ethyl 2-(2-((6-methyl-4-oxo-4H-chromen-3-yl)methylene)hydrazinyl)thiazole-4-carboxylate, obtained by the Hantzsch heterocyclisation reaction. The compound was analyzed through melting point determination, ¹H and ¹³C NMR spectroscopy, infrared, and UV spectroscopy. Full article

(This article belongs to the Collection Heterocycle Reactions)

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Graphical abstract

10 pages, 2472 KB

Open AccessCommunication

Structural and Electronic Insights into Arylalkanones from Myristica ceylanica

by Navaratnarajah Kuganathan and Tharmarajah Manoranjan

Molbank 2026, 2026(1), M2126; https://doi.org/10.3390/M2126 - 20 Jan 2026

Abstract

A phytochemical investigation of Myristica ceylanica resulted in the identification of seven arylalkanone-derived phenolic compounds, comprising one new naturally occurring arylalkanone (A), two derivatives (A₁ and A₂) prepared by chemical synthesis, and four known malabaricones (B–E). Density functional theory (DFT) [...] Read more.

A phytochemical investigation of Myristica ceylanica resulted in the identification of seven arylalkanone-derived phenolic compounds, comprising one new naturally occurring arylalkanone (A), two derivatives (A₁ and A₂) prepared by chemical synthesis, and four known malabaricones (B–E). Density functional theory (DFT) calculations were conducted to evaluate the geometries, electronic properties, and charge distributions of the newly identified arylalkanone and its derivatives and to compare them with those of malabaricones B–E. The arylalkanones exhibited geometrical features comparable to those of the malabaricones, whereas frontier molecular orbital analysis revealed similar HOMO–LUMO energy gaps for the malabaricones but a progressive widening of the gap among the arylalkanone derivatives, indicating enhanced electronic stabilisation. Mulliken population analysis identified oxygen atoms as the principal electron-rich sites in both series, with arylalkanones displaying greater charge polarisation and increased sensitivity to structural substitution. Full article

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5 pages, 650 KB

Open AccessCommunication

Synthesis of 5′-Chlorospiro(benzo[d][1,3]dioxole-2,4′-[1,2,6]thiadiazin)-3′-amine and 10-Chloro-1,4-dioxa-8-thia-7,9-diazaspiro[4.5]deca-6,9-dien-6-amine

by Andreas S. Kalogirou and Panayiotis A. Koutentis

Molbank 2026, 2026(1), M2125; https://doi.org/10.3390/M2125 - 16 Jan 2026

Abstract

Reactions of 3′,5′-dichlorospiro(benzo[d][1,3]dioxole-2,4′-[1,2,6]thiadiazine) or 6,10-dichloro-1,4-dioxa-8-thia-7,9-diazaspiro[4.5]deca-6,9-diene with ammonia in MeCN, at ca. 20 °C, gave 5′-chlorospiro(benzo[d][1,3]dioxole-2,4′-[1,2,6]thiadiazin)-3′-amine and 10-chloro-1,4-dioxa-8-thia-7,9-diazaspiro[4.5]deca-6,9-dien-6-amine, respectively, in near quantitative yields. Full article

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

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5 pages, 260 KB

Open AccessShort Note

Methyl 2-(Chloromethoxy-1-carbonyl)-7-oxabicyclo[2.2.1]heptane-3-carboxylate

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

Molbank 2026, 2026(1), M2124; https://doi.org/10.3390/M2124 - 13 Jan 2026

Abstract

Overexpression of protein phosphatase 5 (PP5) is implicated in tumor cell growth, establishing PP5 as a compelling target for small-molecule anticancer therapy. Building on prior success in achieving selectivity within the PP2A domain through scaffold functionalization that maximizes active-site interactions, we propose a [...] Read more.

Overexpression of protein phosphatase 5 (PP5) is implicated in tumor cell growth, establishing PP5 as a compelling target for small-molecule anticancer therapy. Building on prior success in achieving selectivity within the PP2A domain through scaffold functionalization that maximizes active-site interactions, we propose a parallel strategy for PP5 inhibition. Norcantharidin, the demethylated cousin of cantharidin, is a potent yet unselective phosphatase inhibitor, making its bicyclic framework an attractive platform for systematic derivatization. The approach reported herein exploits anhydride reactivity to generate a carboxylic acid derivative that is transformed into a chloromethyl ester. Chloromethyl ester functionality serves as a strategically activated intermediate enabling downstream functional-group diversification under mild, neutral conditions while preserving scaffold integrity. This modular synthetic strategy establishes a foundation for the development of PP5-selective norcantharidin derivatives with improved tumor selectivity, potency, and synthetic feasibility. Full article

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Scheme 1

6 pages, 966 KB

Open AccessShort Note

N-(2-(1H-Indol-3-yl)ethyl)-2-propylpentanamide

by Diyana Dimitrova, Iliyan Ivanov, Simona Ilieva, Ivelina Cherneva, Dimitar Bojilov and Stanimir Manolov

Molbank 2026, 2026(1), M2123; https://doi.org/10.3390/M2123 - 9 Jan 2026

Abstract

Herein we describe the synthesis of N-(2-(1H-indol-3-yl)ethyl)-2-propylpentanamide. The compound was comprehensively characterized using melting-point analysis, ¹H and ¹³C NMR spectroscopy, infrared spectroscopy, and mass spectrometry. The collective analytical results confirm the successful synthesis and structural integrity of the target molecule. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 790 KB

Open AccessShort Note

6-((2-Oxoindolin-3-ylidene)hydrazineylidene)indolo[2,1-b]quinazolin-12(6H)-one

by Elizaveta I. Samorodova, Anastasia R. Kovrizhina and Andrei I. Khlebnikov

Molbank 2026, 2026(1), M2121; https://doi.org/10.3390/M2121 - 6 Jan 2026

Abstract

A novel unsymmetrical azine, 6-((2-oxoindolin-3-ylidene)hydrazineylidene)indolo[2,1-b]quinazolin-12(6H)-one, was synthesized through a condensation reaction between tryptanthrin-6-hydrazone and isatin in chloroform under reflux conditions. Structural characterization revealed the compound exists as a mixture of geometric isomers with one predominant form. Density functional theory [...] Read more.

A novel unsymmetrical azine, 6-((2-oxoindolin-3-ylidene)hydrazineylidene)indolo[2,1-b]quinazolin-12(6H)-one, was synthesized through a condensation reaction between tryptanthrin-6-hydrazone and isatin in chloroform under reflux conditions. Structural characterization revealed the compound exists as a mixture of geometric isomers with one predominant form. Density functional theory (DFT) calculations identified the E,E configuration as the most stable isomer. The isomerization barriers for both C=N bonds were calculated at approximately 18.5 kcal/mol via nitrogen inversion. Given the established biological activities of tryptanthrin and isatin derivatives, this hybrid azine represents a promising lead compound for developing bifunctional drug candidates. Full article

(This article belongs to the Collection Heterocycle Reactions)

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7 pages, 1120 KB

Open AccessCommunication

Synthesis and Investigation of a Symmetrical Bis(methoxycarbonyl)-Substituted Rubrene Derivative

by Roman A. Irgashev, Alexander S. Steparuk, Gennady L. Rusinov, Ildar R. Sayarov, Alexey E. Aleksandrov and Alexey R. Tameev

Molbank 2026, 2026(1), M2122; https://doi.org/10.3390/M2122 - 6 Jan 2026

Abstract

A symmetrical rubrene derivative, 5,6-bis(4-(methoxycarbonyl)phenyl)-11,12-diphenyltetracene, was synthesized via the thermal dimerization of 1,1-diphenyl-3-[4-(methoxycarbonyl)phenyl]-3-chloroallene. The reaction proceeded with the low selectivity typical of the classical “rubrenic synthesis” under these conditions, affording the target tetracene and the bis(alkylidene)cyclobutene by-product in nearly equal yields of 25% [...] Read more.

A symmetrical rubrene derivative, 5,6-bis(4-(methoxycarbonyl)phenyl)-11,12-diphenyltetracene, was synthesized via the thermal dimerization of 1,1-diphenyl-3-[4-(methoxycarbonyl)phenyl]-3-chloroallene. The reaction proceeded with the low selectivity typical of the classical “rubrenic synthesis” under these conditions, affording the target tetracene and the bis(alkylidene)cyclobutene by-product in nearly equal yields of 25% each. The optical characteristics of this rubrene derivative were investigated, revealing bright orange fluorescence in a CHCl₃ solution (λ_em = 565 nm, Φ_F = 0.81, τ = 11.41 ns), which is strongly quenched in the solid state (Φ_F = 0.01) due to aggregation. Full article

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6 pages, 494 KB

Open AccessShort Note

(Benzo[h]quinoline-κ²C,N)-[2,2′-bis(diphenylphosphino)-1,1′-binaphthalene-κ²P,P′]-platinum(II) Hexafluorophosphate

by Haoni Wang, Meiting Zhang, Jianwei Wu, Junqi Zhang, Xianglong Meng and Yuliang Yang

Molbank 2026, 2026(1), M2120; https://doi.org/10.3390/M2120 - 5 Jan 2026

Abstract

A cyclometalated platinum(II) complex [Pt(bzq)(BINAP)]PF₆ bearing a 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) auxiliary ligand and a cyclometalated benzo[h]quinoline (bzq) ligand have been prepared. Structural characterization was achieved through X-ray crystallography, ¹H, ¹³C and ³¹P NMR spectroscopy, ESI−MS, and elemental analysis. Full article

(This article belongs to the Section Structure Determination)

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7 pages, 1061 KB

Open AccessShort Note

(RS)-6,6,7′,7′-Tetramethyl-2-sulfanylidene-5,6,6′,7′-tetrahydro-2H,2′H,4H,4′H,5′H-spiro[thiopyran-3,3′-thiopyrano [2,3-b]thiopyran]-4,5′-dione

by Werner Seebacher, Antoine Dupé, Eva-Maria Pferschy-Wenzig, Robert Saf, Theresa Hermann and Robert Weis

Molbank 2026, 2026(1), M2117; https://doi.org/10.3390/M2117 - 4 Jan 2026

Abstract

The reaction of aliphatic aldehydes with the tautomers 6,6-dimethyl-4-hydroxy-2H-thiopyrane-2-thione and 6,6-dimethyl-2-mercapto-4H-thiopyrane-4-one is reported to yield spiro compounds. However, the spiro compound of the reaction with formaldehyde is postulated, but has not been isolated to date. Due to a change [...] Read more.

The reaction of aliphatic aldehydes with the tautomers 6,6-dimethyl-4-hydroxy-2H-thiopyrane-2-thione and 6,6-dimethyl-2-mercapto-4H-thiopyrane-4-one is reported to yield spiro compounds. However, the spiro compound of the reaction with formaldehyde is postulated, but has not been isolated to date. Due to a change in reaction conditions, we managed to isolate (RS)-6,6,7′,7′-Tetramethyl-2-sulfanylidene-5,6,6′,7′-tetrahydro-2H,2′H,4H,4′H,5′H-spiro[thiopyran-3,3′-thiopyrano [2,3-b]thiopyran]-4,5′-dione for the first time. The structure was proven with the help of a single X-ray crystal analysis. Furthermore, the new compound was fully characterized using one- and two- dimensional NMR techniques such as ¹H, ¹³C, DEPT, COSY, HSQC and HMBC spectra, as well as IR and HRMS measurements. Full article

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

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Graphical abstract

6 pages, 451 KB

Open AccessShort Note

4-(4-Chlorophenyl)-6-phenyl-2-(prop-2-yn-1-yloxy)nicotinonitrile

by Diana Becerra, Diana Hurtado-Rodríguez and Juan-Carlos Castillo

Molbank 2026, 2026(1), M2119; https://doi.org/10.3390/M2119 - 4 Jan 2026

Abstract

We report an efficient and transition-metal-free protocol for the propargylation of 4-(4-chlorophenyl)-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile using propargyl bromide in the presence of cesium carbonate in dimethylsulfoxide under mild conditions. This synthetic transformation proceeds with marked chemoselectivity, furnishing the O-propargylated pyridine and the N-propargylated 2-pyridone [...] Read more.

We report an efficient and transition-metal-free protocol for the propargylation of 4-(4-chlorophenyl)-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile using propargyl bromide in the presence of cesium carbonate in dimethylsulfoxide under mild conditions. This synthetic transformation proceeds with marked chemoselectivity, furnishing the O-propargylated pyridine and the N-propargylated 2-pyridone in 75% and 8% yields, respectively. Both products were fully characterized by IR and NMR spectroscopy, as well as high-resolution mass spectrometry, confirming their molecular structures. Full article

(This article belongs to the Collection Heterocycle Reactions)

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