Molbank

7 pages, 650 KB

Open AccessShort Note

(2E,2′E)-3,3′-(2,2′-Bipyridine-6,6′-diyl)diacrylic Acid

by Tristan Hergot, Mihayl Varbanov and Florence Dumarçay-Charbonnier

Molbank 2026, 2026(5), M2238; https://doi.org/10.3390/M2238 - 2 Oct 2026

A new carboxylic acid-functionalized 2,2′-bipyridine derivative, (2E,2′E)-3,3′-(2,2′-bipyridine-6,6′-diyl)diacrylic acid (3), was synthesized in two steps from 6,6′-dibromo-2,2′-bipyridine. A palladium-catalyzed double Heck coupling with tert-butyl acrylate afforded the corresponding protected diester intermediate, which was then deprotected under acidic conditions [...] Read more.

A new carboxylic acid-functionalized 2,2′-bipyridine derivative, (2E,2′E)-3,3′-(2,2′-bipyridine-6,6′-diyl)diacrylic acid (3), was synthesized in two steps from 6,6′-dibromo-2,2′-bipyridine. A palladium-catalyzed double Heck coupling with tert-butyl acrylate afforded the corresponding protected diester intermediate, which was then deprotected under acidic conditions to give the target dicarboxylic acid. The compound was fully characterized by ¹H and ¹³C NMR spectroscopy and HRMS. The combination of a 2,2′-bipyridine core with two conjugated carboxylic acid functionalities provides a bifunctional molecular building block potentially suitable for further derivatization. Full article

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

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6 pages, 372 KB

Open AccessCommunication

Synthesis of 2-((2-(4-(Benzyloxy)-4-oxobutanamido)ethyl)dimethylammonio)propane-1-sulfonate and 2-((2-(5-(Benzyloxy)-5-oxopentanamido)ethyl)dimethylammonio)propane-1-sulfonate

by Marta Fiéis, João Sarrato, Ricardo Chagas and Luísa Maria Ferreira

Molbank 2026, 2026(5), M2237; https://doi.org/10.3390/M2237 - 30 Sep 2026

Abstract

Two previously undescribed sulfobetaine zwitterions bearing benzyl ester and amide functionalities were synthesized through a concise three-step sequence starting from benzyl alcohol and either succinic or glutaric anhydride. The route comprised esterification, amidation with -dimethylpropane-1,3-diamine, and ring-opening of 1,3-propanesultone by the resulting tertiary [...] Read more.

Two previously undescribed sulfobetaine zwitterions bearing benzyl ester and amide functionalities were synthesized through a concise three-step sequence starting from benzyl alcohol and either succinic or glutaric anhydride. The route comprised esterification, amidation with -dimethylpropane-1,3-diamine, and ring-opening of 1,3-propanesultone by the resulting tertiary amine. Differing only in the length of the diacid-derived spacer, the two compounds constitute a matched pair well suited to probing structure–property relationships in sulfobetaine surfactants and thermoresponsive materials. Full article

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

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4 pages, 332 KB

Open AccessShort Note

N¹-(1-(naphthalen-2-yl)ethyl)benzene-1,2-diamine

by Lei Gao and Yue Zhang

Molbank 2026, 2026(5), M2236; https://doi.org/10.3390/M2236 - 30 Sep 2026

Abstract

This work reports the synthesis of a previously uncharacterized N¹-(1-(naphthalen-2-yl)ethyl)benzene-1,2-diamine derivative, a member of the aromatic diamine Schiff base family that has not been documented in the existing literature. The full set of ¹H NMR, ¹³C NMR and mass [...] Read more.

This work reports the synthesis of a previously uncharacterized N¹-(1-(naphthalen-2-yl)ethyl)benzene-1,2-diamine derivative, a member of the aromatic diamine Schiff base family that has not been documented in the existing literature. The full set of ¹H NMR, ¹³C NMR and mass spectrometry data provides definitive confirmation of the successful construction and full structural consistency of the target product. Full article

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6 pages, 449 KB

Open AccessCommunication

The Synthesis of 3-(3-(Benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoic Acid

by Yanting Sang, Alessio Iannetti and Mark Ashton

Molbank 2026, 2026(5), M2235; https://doi.org/10.3390/M2235 - 28 Sep 2026

Abstract

This study reports the synthesis of two new compounds, methyl 3-(3-(benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoate and 3-(3-(benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoic acid, prepared via the addition of an amine to an isocyanate to generate the corresponding urea, followed by the base hydrolysis of the ester. Both compounds were characterized by melting [...] Read more.

This study reports the synthesis of two new compounds, methyl 3-(3-(benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoate and 3-(3-(benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoic acid, prepared via the addition of an amine to an isocyanate to generate the corresponding urea, followed by the base hydrolysis of the ester. Both compounds were characterized by melting point determination, 1H and 13C NMR spectroscopy, infrared spectroscopy, and HRMS. Methyl 3-(3-(benzo[d][1,3]dioxol-5-ylmethyl)ureido)benzoate was additionally characterized by CHN elemental analysis. Full article

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7 pages, 1546 KB

Open AccessShort Note

2,3-Diphenyldibenzo[b,f]imidazo[1,2-d][1,4]oxazepine-6,7-dicarbonitrile

by Dmitry Erzunov, Vyacheslav Baklagin, Igor Abramov, Kirill Suponitsky and Arthur Vashurin

Molbank 2026, 2026(5), M2234; https://doi.org/10.3390/M2234 - 25 Sep 2026

Abstract

The study focuses on the synthesis and structural characterization of 2,3-diphenyldibenzo[b,f]imidazo[1,2-d][1,4]oxazepine-6,7-dicarbonitrile. The target compound was obtained via a nucleophilic aromatic substitution reaction between 2-(2-hydroxyphenyl)-4,5-diphenyl-1H-imidazole and 4,5-dichlorophthalonitrile in the presence of potassium carbonate in DMF. The structure was confirmed by IR, ¹H NMR, [...] Read more.

The study focuses on the synthesis and structural characterization of 2,3-diphenyldibenzo[b,f]imidazo[1,2-d][1,4]oxazepine-6,7-dicarbonitrile. The target compound was obtained via a nucleophilic aromatic substitution reaction between 2-(2-hydroxyphenyl)-4,5-diphenyl-1H-imidazole and 4,5-dichlorophthalonitrile in the presence of potassium carbonate in DMF. The structure was confirmed by IR, ¹H NMR, ¹³C NMR spectroscopy, mass spectrometry, and elemental analysis. The molecular packing and intermolecular interactions were elucidated by single-crystal X-ray diffraction analysis. The crystal structure reveals the presence of one independent molecule in the asymmetric unit, stabilized by weak C–H···π, C–H···N, H···H and π···π interactions. Full article

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6 pages, 1039 KB

Open AccessShort Note

1,2-Dimethoxy-12-methyl-13H-[1,3]benzodioxolo[5,6-c]phenanthridine

by Peter Mbugua Njogu, Benson Joseph Atako, Kennedy Abuga, John Norman Lisgarten, Jeremy Karl Cockcroft and Grace Njeri Thoithi

Molbank 2026, 2026(5), M2233; https://doi.org/10.3390/M2233 - 22 Sep 2026

Abstract

The crystal structure of the benzophenanthridine alkaloid dihydrochelerythrine (1,2-dimethoxy-12-methyl-13H-[1,3]benzodioxolo[5,6-c]phenanthridine), C₂₁H₁₉NO₄, was determined by single-crystal X-ray diffraction analysis. The alkaloid was isolated from the stem bark of Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae), collected from Nairobi, Kenya. [...] Read more.

The crystal structure of the benzophenanthridine alkaloid dihydrochelerythrine (1,2-dimethoxy-12-methyl-13H-[1,3]benzodioxolo[5,6-c]phenanthridine), C₂₁H₁₉NO₄, was determined by single-crystal X-ray diffraction analysis. The alkaloid was isolated from the stem bark of Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae), collected from Nairobi, Kenya. In contrast to the earlier reported semisynthetic form, which crystallised in the monoclinic space group P2₁/c, the present natural isolate adopts the orthorhombic Pbca space group. The molecule displays an approximately planar benzophenanthridine framework, but with the dihydro group resulting in a distinctly puckered ring and an out-of-plane methyl group on the tertiary amine. Non-covalent interactions are responsible for the characteristic herringbone packing motif. Full article

(This article belongs to the Section Natural Product Chemistry)

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10 pages, 1184 KB

Open AccessCommunication

Synthesis, Spectroscopic Characterization, and Thermal Analysis of (E)-1-(2-Hydroxy-4-methoxyphenyl)-3-(5-methylfuran-2-yl)prop-2-en-1-one

by Julián A. Contreras-Pérez, Karen D. Rojas-Ramírez, Paola Acosta-Guzmán, Hugo Rojas, Diana Becerra and Juan-Carlos Castillo

Molbank 2026, 2026(5), M2232; https://doi.org/10.3390/M2232 - 17 Sep 2026

Abstract

Herein, the previously unreported (E)-1-(2-hydroxy-4-methoxyphenyl)-3-(5-methylfuran-2-yl)prop-2-en-1-one 3 was synthesized by Claisen–Schmidt condensation of 1-(2-hydroxy-4-methoxyphenyl)ethan-1-one 1 and 5-methylfuran-2-carbaldehyde 2 using potassium hydroxide in an ethanol/water mixture at 50 °C. The protocol afforded 3 in 85% yield with high atom economy (93.5%), an EcoScale [...] Read more.

Herein, the previously unreported (E)-1-(2-hydroxy-4-methoxyphenyl)-3-(5-methylfuran-2-yl)prop-2-en-1-one 3 was synthesized by Claisen–Schmidt condensation of 1-(2-hydroxy-4-methoxyphenyl)ethan-1-one 1 and 5-methylfuran-2-carbaldehyde 2 using potassium hydroxide in an ethanol/water mixture at 50 °C. The protocol afforded 3 in 85% yield with high atom economy (93.5%), an EcoScale score of 61.5, and partial material recovery (MRP = 0.65). The product was comprehensively characterized by FT–IR, NMR, UV–Vis, EI–MS, HRMS, TG, and DSC analyses. UV–Vis and solvatochromic studies revealed a bathochromic shift in the lowest-energy absorption band with increasing solvent polarity, indicating a solvent-dependent electronic response consistent with the extended conjugation of the chalcone framework. Full article

(This article belongs to the Collection Heterocycle Reactions)

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9 pages, 2070 KB

Open AccessCommunication

Crystal Structure of 1,1-Dimethyl-3-(quinolin-2-yl)urea and 3-(Isoquinolin-1-yl)-1,1-dimethylurea

by Svetlana O. Baykova, Sergey V. Baykov, Vadim P. Boyarskiy and Nadezhda A. Bokach

Molbank 2026, 2026(5), M2231; https://doi.org/10.3390/M2231 - 16 Sep 2026

Abstract

The crystal structures of two isomeric urea derivatives—1,1-dimethyl-3-(quinolin-2-yl)urea (1) and 3-(isoquinolin-1-yl)-1,1-dimethylurea (2)—have been investigated by single-crystal X-ray diffraction. These compounds differ in the relative position of the heterocyclic nitrogen atom and the urea substituent. A structural study revealed that [...] Read more.

The crystal structures of two isomeric urea derivatives—1,1-dimethyl-3-(quinolin-2-yl)urea (1) and 3-(isoquinolin-1-yl)-1,1-dimethylurea (2)—have been investigated by single-crystal X-ray diffraction. These compounds differ in the relative position of the heterocyclic nitrogen atom and the urea substituent. A structural study revealed that the compounds exhibit distinct molecular conformations. In 1, the molecule exists predominantly in a ureide form with a single C–N bond between the quinoline fragment and urea moiety. The ureide group is out of the plane of the quinoline ring, forming an anti-conformation. In contrast, 2 adopts an exocyclic C=N configuration with an intramolecular hydrogen bond between the heterocyclic NH group and ureide oxygen, resulting in a syn-conformation. The supramolecular organization of the compounds also differs: 1 forms one-dimensional chains through N–H···O hydrogen bonds, which further assemble into two-dimensional layers via C–H···O interactions; in 2, the molecules form dimers through intermolecular C–H···O hydrogen bonds. Thus, subtle structural differences between isomeric urea derivatives can lead to distinct molecular conformations, tautomeric forms, and supramolecular organizations. Full article

(This article belongs to the Section Structure Determination)

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9 pages, 1486 KB

Open AccessCommunication

Bis(triphenylphosphine)iminium Salts of the Low-Valent Carbonyltechnetates [Tc₂(CO)₉Cl]⁻ and [Tc(CO)₃Cl₃]²⁻

by Jonas Genz, Maximilian Roca Jungfer and Ulrich Abram

Molbank 2026, 2026(5), M2230; https://doi.org/10.3390/M2230 - 15 Sep 2026

Abstract

Reduction of [Tc(CO)₅Br] with sodium amalgam, sodium naphthalenide, or potassium graphite in THF and subsequent addition of bis(triphenylphosphine)iminium chloride, (PPN)Cl, gave mixtures of the orange-yellow Tc(0) compound (PPN)[Tc(CO)₉Cl], (PPN)[1], and the colorless Tc(I) complex (PPN)₂[Tc(CO) [...] Read more.

Reduction of [Tc(CO)₅Br] with sodium amalgam, sodium naphthalenide, or potassium graphite in THF and subsequent addition of bis(triphenylphosphine)iminium chloride, (PPN)Cl, gave mixtures of the orange-yellow Tc(0) compound (PPN)[Tc(CO)₉Cl], (PPN)[1], and the colorless Tc(I) complex (PPN)₂[Tc(CO)₃Cl₃], (PPN)₂[2]. The products have been studied by X-ray diffraction and NMR spectroscopy. The dimeric compound [1]⁻ represents the first example of an anionic technetium(0) complex with only one halide ligand in its coordination sphere. The equatorial carbonyl (and chlorido) ligands at the two technetium atoms show the expected staggered conformation around the (CO)Tc–Tc(CO) axis. The Tc–Tc bond is 3.0269(7) Å. The different nature of the two technetium atoms in compound [1]⁻ is reflected by the appearance of two different ⁹⁹Tc NMR signals in CD₂Cl₂ at −1770 and −2487 ppm, while the corresponding signal of the technetium(I) anion [2]²⁻ appears at −953 ppm in the same solvent. Anion [2]²⁻ shows the expected facial arrangement of the carbonyl and chlorido ligands. The use of the bulky PPN⁺ cation allowed the first determination of the [Tc(CO)₃Cl₃]²⁻ structure by X-ray diffraction without significant interference due to disorder effects in the coordination sphere of the transition metal. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

5 pages, 324 KB

Open AccessCommunication

Synthesis and Characterization of Acylhydrazone Derivative from Strictic Acid

by Tianqiong Lang, Min Lu, Huihong Chen and Linlin Song

Molbank 2026, 2026(5), M2229; https://doi.org/10.3390/M2229 - 7 Sep 2026

Abstract

Under the application of a semi-synthesis strategy, an acylhydrazone derivative from strictic acid (SA), a natural neo-clerodane diterpenoid with a unique 5,10-seco skeleton isolated from Schnabelia terniflora, has been synthesized via a two-step synthetic pathway including hydrazide formation from the carboxylic [...] Read more.

Under the application of a semi-synthesis strategy, an acylhydrazone derivative from strictic acid (SA), a natural neo-clerodane diterpenoid with a unique 5,10-seco skeleton isolated from Schnabelia terniflora, has been synthesized via a two-step synthetic pathway including hydrazide formation from the carboxylic acid moiety of SA and further hydrazonation with p-methylcinnamaldehyde. The target structure was confirmed by ¹H NMR, ¹³C NMR and HRMS data. Full article

(This article belongs to the Section Natural Product Chemistry)

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8 pages, 5897 KB

Open AccessCommunication

Novel Fluorinated Derivatives of 2-Phenyl-1H-Indole

by Larisa Politanskaya and Irina Bagryanskaya

Molbank 2026, 2026(5), M2228; https://doi.org/10.3390/M2228 - 4 Sep 2026

Abstract

The indole core is a structural component of a huge number of biologically active natural and synthesized compounds and pharmaceuticals, and their efficient synthesis is an important challenge. Fluorinated indoles have attracted considerable attention, since it was established that fluorine introduction can influence [...] Read more.

The indole core is a structural component of a huge number of biologically active natural and synthesized compounds and pharmaceuticals, and their efficient synthesis is an important challenge. Fluorinated indoles have attracted considerable attention, since it was established that fluorine introduction can influence the biological activity of organic molecules. The initial PdCl₂-catalyzed intramolecular cyclization of 4,5-difluoro-2-(phenylethynyl)aniline led to the formation of the corresponding indole in high yield. The result of its subsequent treatment with Selectfluor was the introduction of one or two fluorine atoms onto position 3. The reaction products were isolated individually by preparative thin-layer chromatography and characterized by spectroscopic methods, including IR, ¹H NMR, ¹⁹F NMR, ¹³C NMR and HRMS. The structure of indole, exhaustively fluorinated at position 3—3,3,5,6-tetrafluoro-2-phenyl-3H-indole—was confirmed through single-crystal X-ray diffraction analysis. Full article

(This article belongs to the Collection Heterocycle Reactions)

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7 pages, 2604 KB

Open AccessCommunication

Synthesis and Structure of Macrocyclic Tetraimidazolium Salt Containing Propylene and m-Phenylene Linkers

by Jun-Ichi Ito and Makoto Yamashita

Molbank 2026, 2026(5), M2227; https://doi.org/10.3390/M2227 - 2 Sep 2026

Abstract

Macrocyclic tetraimidazolium salts 2 and 3 containing propylene and m-phenylene linkers were synthesized from diimidazole derivative 1 and 1,3-diiodopropane. The molecular structure of 3 was determined by single-crystal X-ray diffraction analysis, revealing an almost planar macrocyclic framework. DFT calculations identified three low-energy [...] Read more.

Macrocyclic tetraimidazolium salts 2 and 3 containing propylene and m-phenylene linkers were synthesized from diimidazole derivative 1 and 1,3-diiodopropane. The molecular structure of 3 was determined by single-crystal X-ray diffraction analysis, revealing an almost planar macrocyclic framework. DFT calculations identified three low-energy conformers of the tetracation in 3, suggesting conformational flexibility in solution. Full article

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Graphical abstract

5 pages, 1329 KB

Open AccessShort Note

(5aS,8R,9aR)-5,5,8-Trimethyloctahydrobenzo[f][1,4]oxazepin-3(2H)-one

by Nikolai S. Li-Zhulanov, Dmitrii D. Golovchenko, Tatyana V. Rybalova, Maria E. Modelskaya, Artem D. Rogachev, Konstantin P. Volcho and Nariman F. Salakhutdinov

Molbank 2026, 2026(5), M2225; https://doi.org/10.3390/M2225 - 1 Sep 2026

Abstract

The monoterpene-derived 1,4-oxazepan-3-one, (5aS,8R,9aR)-5,5,8-trimethyloctahydrobenzo[f][1,4]oxazepin-3(2H)-one, was synthesized from the corresponding (−)-isopulegol-based chloroacetamide by intramolecular cyclization in acetonitrile. The product was isolated in 70% yield as colorless crystals. Its structure was established by one- and [...] Read more.

The monoterpene-derived 1,4-oxazepan-3-one, (5aS,8R,9aR)-5,5,8-trimethyloctahydrobenzo[f][1,4]oxazepin-3(2H)-one, was synthesized from the corresponding (−)-isopulegol-based chloroacetamide by intramolecular cyclization in acetonitrile. The product was isolated in 70% yield as colorless crystals. Its structure was established by one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry and was confirmed by single-crystal X-ray diffraction analysis. The transformation provides concise access to a fused bicyclic 1,4-oxazepan-3-one bearing a stereochemically defined para-menthane scaffold. Full article

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Graphical abstract

8 pages, 1940 KB

Open AccessCommunication

Synthesis and Structural Characterization of a New One-Dimensional Zinc(II) Coordination Polymer Based on a Fluorinated Thiosemicarbazone Schiff Base Ligand

by Jinhua Wang, Guan Wang and Chengwen Li

Molbank 2026, 2026(5), M2224; https://doi.org/10.3390/M2224 - 1 Sep 2026

Abstract

This study reports the synthesis and characterization of a dinuclear zinc(II) complex, [Zn₂(L1)₂(L2)]·DMF·Et₃N (C₄₅H₅₄F₂N₁₀O₅S₂Zn₂), constructed from a fluoro-substituted thiosemicarbazone [...] Read more.

This study reports the synthesis and characterization of a dinuclear zinc(II) complex, [Zn₂(L1)₂(L2)]·DMF·Et₃N (C₄₅H₅₄F₂N₁₀O₅S₂Zn₂), constructed from a fluoro-substituted thiosemicarbazone Schiff base ligand (2-(3-fluoro-5-hydroxybenzylidene)-N-methylhydrazine-1-carbothioamide, L1) and a rigid bipyridine auxiliary ligand (1,4-di(pyridin-4-yl)-2,5-dimethoxybenzene, L2) under solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the monoclinic space group C2/c, featuring discrete dinuclear [Zn₂] units in which each Zn(II) center adopts a distorted square pyramidal geometry. These dinuclear units are extended into one-dimensional zigzag chains along the crystallographic c-axis via bridging L2 ligands, and further assembled into a two-dimensional supramolecular layer through hydrogen-bonding interactions involving lattice triethylamine and DMF molecules, ultimately forming a three-dimensional network. Both DMF and triethylamine molecules are disordered about a twofold rotation axis. This work highlights the structural directing roles of the fluoro-substituted multidentate Schiff base ligand and the rigid auxiliary ligand in the assembly of zinc(II) coordination polymers. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 474 KB

Open AccessShort Note

N-[3-(N-tert-Butoxycarbonylaminooxy)propyl]-2-[2-(3-butynylcarbonylamino)ethylthio]-1,3-benzothiazole-6-carboxamide

by Gabriella G. Meisner, Nora N. Veigas and Christopher R. Shugrue

Molbank 2026, 2026(5), M2226; https://doi.org/10.3390/M2226 - 1 Sep 2026

Abstract

We report the synthesis of a modified benzothiazole sulfide. This compound contains a heterocyclic core, a Boc-protected hydroxylamine, and an appended alkyne. This benzothiazole was accessed through three total steps, including an amidation reaction and two nucleophilic aromatic substitutions. The identity of the [...] Read more.

We report the synthesis of a modified benzothiazole sulfide. This compound contains a heterocyclic core, a Boc-protected hydroxylamine, and an appended alkyne. This benzothiazole was accessed through three total steps, including an amidation reaction and two nucleophilic aromatic substitutions. The identity of the title compound was confirmed through ¹H, ¹³C, ¹H–¹H COSY, HSQC, and HMBC NMR, in addition to IR, MALDI-MS, HRMS, and HPLC. Full article

(This article belongs to the Collection Heterocycle Reactions)

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Graphical abstract

8 pages, 1498 KB

Open AccessShort Note

5-Cyano-7-(2-hydroxyphenyl)-4-[(2-hydroxyphenyl)amino]pyrrolo[2,3-c][1,2,6]thiadiazin-6(7H)-iminium Chloride Hydrate

by Andreas S. Kalogirou, Andreas Kourtellaris and Panayiotis A. Koutentis

Molbank 2026, 2026(4), M2222; https://doi.org/10.3390/M2222 - 18 Aug 2026

Abstract

Reaction of 2-(3,5-dichloro-4H-1,2,6-thiadiazin-4-ylidene)malononitrile with sodium 2-aminophenolate (1.5 equiv.) in anhydrous THF at ca. 0–20 °C afforded the known 4-chlorobenzo[5,6][1,4]oxazino[2,3-c][1,2,6]thiadiazine in 76% yield. In contrast, treatment of the same substrate with 2-aminophenol (3 equiv.) in acetonitrile at ca. [...] Read more.

Reaction of 2-(3,5-dichloro-4H-1,2,6-thiadiazin-4-ylidene)malononitrile with sodium 2-aminophenolate (1.5 equiv.) in anhydrous THF at ca. 0–20 °C afforded the known 4-chlorobenzo[5,6][1,4]oxazino[2,3-c][1,2,6]thiadiazine in 76% yield. In contrast, treatment of the same substrate with 2-aminophenol (3 equiv.) in acetonitrile at ca. 20 °C gave 5-cyano-7-(2-hydroxyphenyl)-4-[(2-hydroxyphenyl)amino]pyrrolo[2,3-c][1,2,6]thiadiazin-6(7H)-iminium chloride hydrate in 93% yield. This compound was characterized by ¹H and ¹³C NMR, IR and UV-vis and mass spectrometry, together with melting point and elemental analysis, and its structure was supported by single-crystal X-ray crystallography. Full article

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8 pages, 922 KB

Open AccessShort Note

2-([1,1′-Biphenyl]-4-yl)-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one

by Yuki Sawatari, Kazunobu Igawa, Eiji Tsurumaki and Gen-ichi Konishi

Molbank 2026, 2026(4), M2223; https://doi.org/10.3390/M2223 - 18 Aug 2026

Abstract

The previously unreported seven-membered-ring benzanilide derivative, 2-([1,1′-biphenyl]-4-yl)-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (1), was synthesized and structurally characterized by spectroscopic methods and single-crystal X-ray diffraction analysis. The crystal structures of 1 and the known six-membered-ring analogue (2) were compared with [...] Read more.

The previously unreported seven-membered-ring benzanilide derivative, 2-([1,1′-biphenyl]-4-yl)-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (1), was synthesized and structurally characterized by spectroscopic methods and single-crystal X-ray diffraction analysis. The crystal structures of 1 and the known six-membered-ring analogue (2) were compared with that of the corresponding five-membered-ring analogue (3). Increasing ring size was found to induce steric distortions around the amide moiety, resulting in systematic changes in the π-conjugation with the adjacent phenyl groups. This study establishes a structural basis for controlling the electronic properties of ring-fixed benzanilides through ring-size engineering. Full article

(This article belongs to the Section Structure Determination)

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10 pages, 2430 KB

Open AccessCommunication

Synthesis and Structure of Palladium(II) Complex with (2E)-2-[1-(4-Aminophenyl)ethylidene]hydrazine-1-carbothioamide

by Daria S. Levchenko, Artem S. Igonin, Ekaterina I. Isaeva, Ruslan I. Baichurin, Oleg P. Demidov and Sergey V. Makarenko

Molbank 2026, 2026(4), M2221; https://doi.org/10.3390/M2221 - 17 Aug 2026

Abstract

This work presents the synthesis and structural characterization of a previously unknown palladium(II) complex with (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide, which in the solid state forms a highly symmetric tetrametallic metallamacrocycle. The structure of the synthesized (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide and corresponding palladium(II) complex was established [...] Read more.

This work presents the synthesis and structural characterization of a previously unknown palladium(II) complex with (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide, which in the solid state forms a highly symmetric tetrametallic metallamacrocycle. The structure of the synthesized (2E)-2-[1-(4-aminophenyl)ethylidene]hydrazine-1-carbothioamide and corresponding palladium(II) complex was established by ¹H, ¹³C–{¹H}, ¹H–¹³C HMQC, and ¹H–¹³C HMBC NMR spectroscopy; IR and UV spectroscopy; mass spectrometry; TGA/DSC analyses; and single-crystal X-ray diffraction. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 320 KB

Open AccessShort Note

1-[(4S)-4-Benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium Tetrafluoroborate

by Jakub Adamek, Natalia Sępek and Agnieszka Październiok-Holewa

Molbank 2026, 2026(4), M2220; https://doi.org/10.3390/M2220 - 17 Aug 2026

Abstract

1-[(4S)-4-benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium tetrafluoroborate was synthesized in a two-step procedure starting from (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one. In the first step, (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one was treated with DIBAL-H at −78 °C in DCM and then converted to (4S)-4-benzyl-3-(1-trimethylsilyloxy)propyl-1,3-oxazolidin-2-one with TMSOTf at −78 °C [...] Read more.

1-[(4S)-4-benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium tetrafluoroborate was synthesized in a two-step procedure starting from (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one. In the first step, (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one was treated with DIBAL-H at −78 °C in DCM and then converted to (4S)-4-benzyl-3-(1-trimethylsilyloxy)propyl-1,3-oxazolidin-2-one with TMSOTf at −78 °C in DCM in the presence of pyridine. Next, the silylated intermediate was transformed to the expected 1-[(4S)-4-benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium tetrafluoroborate by reaction with Ph₃P·HBF₄ at −40 °C in DCM. The structures of the compounds obtained were confirmed by spectroscopic methods (¹H-, ¹³C{¹H}-, ³¹P{¹H}-NMR, IR) and HRMS analysis. Full article

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

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