Molbank

6 pages, 350 KB

Open AccessCommunication

Synthesis of (S)-4-Benzyl-3-butyl-1-(2-cycloheptylethyl)imidazolidine

by Matevž Schweiger, Luka Ciber, Nejc Petek, Franc Požgan, Jurij Svete, Bogdan Štefane and Uroš Grošelj

Molbank 2026, 2026(2), M2166; https://doi.org/10.3390/M2166 - 16 Apr 2026

Viewed by 455

Abstract

LiAlH₄ reduction of tert-butyl (S)-butyl(1-((2-cycloheptylethyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (1) gave imidazolidine 2, while treatment with lithium diisopropylamide furnished the β-elimination product, cinnamamide 3. Both products were fully characterized. Reductive cyclization of N-alkylated-N-Boc-protected amino acid amides [...] Read more.

LiAlH₄ reduction of tert-butyl (S)-butyl(1-((2-cycloheptylethyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (1) gave imidazolidine 2, while treatment with lithium diisopropylamide furnished the β-elimination product, cinnamamide 3. Both products were fully characterized. Reductive cyclization of N-alkylated-N-Boc-protected amino acid amides with LiAlH₄ may be a viable synthetic method for trisubstituted chiral imidazolidines. Full article

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

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6 pages, 869 KB

Open AccessCommunication

Synthesis of 2-Aminonicotinonitriles via Photodecarboxylation of Azirine-2-Carboxylic Acids

by Julia I. Pavlenko, Mikhail S. Novikov and Anastasiya V. Agafonova

Molbank 2026, 2026(2), M2165; https://doi.org/10.3390/M2165 - 14 Apr 2026

Viewed by 421

Abstract

2-Aminonicotinonitriles represent an important class of heterocycles with diverse biological activities. Herein, we report an unexpected photochemical transformation of azirine-2-carboxylic acids leading to the formation of 2-aminonicotinonitrile derivatives. Optimization of the reaction conditions enabled the synthesis of the target products in moderate yields. [...] Read more.

2-Aminonicotinonitriles represent an important class of heterocycles with diverse biological activities. Herein, we report an unexpected photochemical transformation of azirine-2-carboxylic acids leading to the formation of 2-aminonicotinonitrile derivatives. Optimization of the reaction conditions enabled the synthesis of the target products in moderate yields. The structure of the obtained product was confirmed by NMR spectroscopy, HRMS, and single-crystal X-ray diffraction analysis. Full article

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

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8 pages, 2115 KB

Open AccessCommunication

A Bulky Aryl–Substituted Acridinium Salt: 10-(3,5-Di-tert-butylphenyl)-9-mesitylacridinium Tetrafluoroborate

by Yuki Itabashi and Kei Ohkubo

Molbank 2026, 2026(2), M2164; https://doi.org/10.3390/M2164 - 14 Apr 2026

Viewed by 560

Abstract

9-Mesitylacridinium salts are widely recognized as efficient organic photoredox catalysts owing to their strong excited-state oxidizing power and stability under visible-light irradiation. In this study, a new mesityl acridinium derivative bearing a di-tert-butylphenyl substituent on the nitrogen atom was synthesized. The [...] Read more.

9-Mesitylacridinium salts are widely recognized as efficient organic photoredox catalysts owing to their strong excited-state oxidizing power and stability under visible-light irradiation. In this study, a new mesityl acridinium derivative bearing a di-tert-butylphenyl substituent on the nitrogen atom was synthesized. The introduction of tert-butyl groups on the N-aryl moiety was primarily aimed at improving solubility and chemical stability of the acridinium salt. Starting from a 9(10H)-acridinone precursor, the target compound was obtained in high overall yield through a concise synthetic sequence. The synthesis consists of a copper-catalyzed C–N coupling reaction to install the aryl substituent on the nitrogen atom, followed by a Grignard reaction and subsequent acid treatment to afford the corresponding acridinium salt. All transformations proceeded smoothly, providing efficient access to the desired novel acridinium derivative. This work presents a practical example of the structural modification of mesitylacridinium derivatives directed toward enhanced solubility and stability, and provides a useful synthetic platform for the preparation of structurally diverse acridinium salts. Full article

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

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6 pages, 470 KB

Open AccessCommunication

Synthesis of 2-Methylcamalexin

by Yordan Stremski, Maria Bachvarova, Stela Statkova-Abeghe and Plamen Angelov

Molbank 2026, 2026(2), M2163; https://doi.org/10.3390/M2163 - 13 Apr 2026

Viewed by 483

Abstract

2-methylcamalexin, a novel derivative of the phytoalexin Camalexin, was synthesized for the first time, using a convenient two-step approach. The approach realizes coupling of two aromatic heterocyclic moieties (2-methylindole and thiazole) by sequential α-amidoalkylation/oxidative re-aromatization. The target product was obtained in a cost-effective [...] Read more.

2-methylcamalexin, a novel derivative of the phytoalexin Camalexin, was synthesized for the first time, using a convenient two-step approach. The approach realizes coupling of two aromatic heterocyclic moieties (2-methylindole and thiazole) by sequential α-amidoalkylation/oxidative re-aromatization. The target product was obtained in a cost-effective manner, with 88% yield over two steps. The structure of the synthesized product was unequivocally determined on the basis of NMR, HRMS and FTIR spectral measurments. Full article

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

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4 pages, 428 KB

Open AccessShort Note

[2-{(5′-Amino-2′-fluoroacetophenone)-5-nitro}]acetophenone

by Richard M. Beteck and Lesetja J. Legoabe

Molbank 2026, 2026(2), M2162; https://doi.org/10.3390/M2162 - 10 Apr 2026

Viewed by 391

Abstract

Herein we reported on a one-pot nitro reduction/nucleophilic aromatic substitution on 1-(2-fluoro-5-nitrophenyl)ethan-1-one using a mixture of acetic acid and iron powder in ethanol. The resultant target compound, a nitrated N bis-acetophenone, has many reactive handles; as such, it is a novel intermediate that [...] Read more.

Herein we reported on a one-pot nitro reduction/nucleophilic aromatic substitution on 1-(2-fluoro-5-nitrophenyl)ethan-1-one using a mixture of acetic acid and iron powder in ethanol. The resultant target compound, a nitrated N bis-acetophenone, has many reactive handles; as such, it is a novel intermediate that can be deployed for the syntheses of a vast array of compounds not reported before. This compound is fully characterized using ¹H and ¹³C NMR spectroscopy, and HRMS. Full article

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

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Graphical abstract

8 pages, 797 KB

Open AccessShort Note

Racemic-Benzimidazolyl Pentafluorobenzyl Sulfoxide

by Maria Annunziata M. Capozzi and Cosimo Cardellicchio

Molbank 2026, 2026(2), M2161; https://doi.org/10.3390/M2161 - 10 Apr 2026

Viewed by 382

Abstract

As a part of our research on the presence of conglomerates among the aryl benzyl sulfoxides, racemic-benzimidazolyl pentafluorobenzyl sulfoxide was synthesised, and its crystal structure was determined by a single crystal X-ray diffraction experiment. The main interactions building up the crystal structure [...] Read more.

As a part of our research on the presence of conglomerates among the aryl benzyl sulfoxides, racemic-benzimidazolyl pentafluorobenzyl sulfoxide was synthesised, and its crystal structure was determined by a single crystal X-ray diffraction experiment. The main interactions building up the crystal structure were recognised and compared with those of similar compounds. Since the crystal structures of racemic and enantiopure benzimidazolyl pentafluorobenzyl sulfoxides are different, the presence of a conglomerate is excluded in the present case. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

10 pages, 1645 KB

Open AccessShort Note

1-Phenyl-4-p-tolyl-[1,2,3]triazole

by Eder Y. Nolasco-Terrón, David Gómez-Colín, Nelly González-Rivas, Diego Martínez-Otero and Erick Cuevas-Yañez

Molbank 2026, 2026(2), M2160; https://doi.org/10.3390/M2160 - 8 Apr 2026

Viewed by 451

Abstract

1-Phenyl-4-p-tolyl-[1,2,3]triazole was obtained via a CuAAC reaction involving phenyl azide and 1-ethynyl-4-methylbenzene. The NMR spectra of the compound are discussed, and its crystal structure was studied by X-ray analysis. According to the latter analysis and a Hirshfeld surface analysis, the predominant intermolecular C-H⋅⋅⋅N [...] Read more.

1-Phenyl-4-p-tolyl-[1,2,3]triazole was obtained via a CuAAC reaction involving phenyl azide and 1-ethynyl-4-methylbenzene. The NMR spectra of the compound are discussed, and its crystal structure was studied by X-ray analysis. According to the latter analysis and a Hirshfeld surface analysis, the predominant intermolecular C-H⋅⋅⋅N and C-H⋅⋅⋅π interactions in this molecule are responsible for crystal packing. Full article

(This article belongs to the Section Structure Determination)

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7 pages, 381 KB

Open AccessShort Note

Synthesis of a Calix[4]semitube with a Selectively Dinitrated Face

by Roderick Abdilla, Stefano Volpi, Alessandro Casnati, Maria A. Cardona and Ruben Gatt

Molbank 2026, 2026(2), M2159; https://doi.org/10.3390/M2159 - 7 Apr 2026

Viewed by 383

Abstract

This paper describes the synthesis and characterisation of the calix semitube 5. The calix[4]semitube consists of two calix[4]arenes connected through their lower rim from two phenol groups in distal positions. One calix[4]arene is unsubstituted on its upper rim, while the upper rim [...] Read more.

This paper describes the synthesis and characterisation of the calix semitube 5. The calix[4]semitube consists of two calix[4]arenes connected through their lower rim from two phenol groups in distal positions. One calix[4]arene is unsubstituted on its upper rim, while the upper rim of the other calix[4]arene has two nitro groups in the 1,3- position and two tert-butyl groups in the remaining ones. The synthesis procedure yielded an amorphous structure, which did not provide a single crystal. The final compound was comprehensively characterised by infrared spectroscopy, mass spectrometry, and ¹H and ¹³C NMR spectroscopy. The results of the ¹H NMR spectroscopy confirmed that the calix[4]arene units adopted a cone conformation. This was confirmed by COSY and ¹H-¹³C HMBC. The results obtained confirm that the compound was successfully synthesised. The IUPAC name of 5 is 2,34-di-tert-butyl-39,49-dinitro-6,7,8,9,27,28,29,30-octahydro-15H,21H,36H,42H-4,32:11,25-bis(methano [1,3]benzenomethano)-16,20:37,41-di(metheno)tetrabenzo[g,g1,p,x][1,6,18,23] tetraoxacyclotetratriacontine-43,46,54,60-tetraol. Full article

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

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5 pages, 356 KB

Open AccessShort Note

(1S,2R,3aR,6S,8aS)-1-Isopropyl-3a,6-Dimethyldecahydroazulene-1,2,6-Triol from Trichoderma virens

by Desita Triana Aziz, Resky Nugraha, Marwah Wirda Ningsih, Zetryana Puteri Tachrim, Yuta Murai and Makoto Hashimoto

Molbank 2026, 2026(2), M2158; https://doi.org/10.3390/M2158 - 2 Apr 2026

Viewed by 531

Abstract

A novel derivative from carotene-type sesquiterpene, (1S,2R,3aR,6S,8aS)-1-isopropyl-3a,6-dimethyldecahydroazulene-1,2,6-triol (1), was successfully isolated from filamentous fungus Trichoderma virens NBRC 31959. The structure and molecular formula of 1 were determined by interpretation of 1D [...] Read more.

A novel derivative from carotene-type sesquiterpene, (1S,2R,3aR,6S,8aS)-1-isopropyl-3a,6-dimethyldecahydroazulene-1,2,6-triol (1), was successfully isolated from filamentous fungus Trichoderma virens NBRC 31959. The structure and molecular formula of 1 were determined by interpretation of 1D and 2D NMR and HRMS data. The absolute configuration was established unambiguously by single-crystal X-ray diffraction, with the Flack parameter supporting the assignment. This study adds to the chemical diversity of sesquiterpene-type CAF603 derivatives of Trichoderma virens. Full article

(This article belongs to the Section Natural Product Chemistry)

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4 pages, 407 KB

Open AccessShort Note

(+)-(3S)-8-(3-Methylbut-2-en-1-yl)-7-Methoxy-6,2′,4′-Trihydroxyisoflavan

by Hye Jin Kim, Kye Jung Shin, Khin Myo Htwe and Kee Dong Yoon

Molbank 2026, 2026(2), M2157; https://doi.org/10.3390/M2157 - 2 Apr 2026

Viewed by 307

Abstract

Phytochemical investigation of Millettia racemosa Benth. led to the identification of an undescribed isoflavan, (+)-(3S)-8-(3-methylbut-2-en-1-yl)-7-methoxy-6,2′,4′-trihydroxyisoflavan, namely milletiaisoflavan (1). The structure of the isolate was elucidated by spectroscopic evidence (one- and two-dimensional nuclear magnetic resonance, ultraviolet, mass spectrometry, and circular dichroism spectra). Full article

(This article belongs to the Section Natural Product Chemistry)

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6 pages, 293 KB

Open AccessShort Note

(E)-3-(3,4-Di-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyloxy)phenyl) Acrylic Acid

by Sara Ghazi and Mohamed Touaibia

Molbank 2026, 2026(2), M2156; https://doi.org/10.3390/M2156 - 1 Apr 2026

Viewed by 414

Abstract

Phenolic acids are widely known for their antioxidant and biological properties, which make them attractive scaffolds for structural modification. In this short note, we report the synthesis of a new 3,4-di-glucosylated caffeic acid analogue. The (E)-3-(3,4-di-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyloxy)phenyl) acrylic [...] Read more.

Phenolic acids are widely known for their antioxidant and biological properties, which make them attractive scaffolds for structural modification. In this short note, we report the synthesis of a new 3,4-di-glucosylated caffeic acid analogue. The (E)-3-(3,4-di-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyloxy)phenyl) acrylic acid was obtained through a two-step synthesis, starting with a phase-transfer-catalyzed glycosylation of 3,4-dihydroxybenzaldehyde with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide followed by a Dobner-modified Knoevenagel condensation. Consistent with the 2-O-acetyl neighbouring participation and the resulting Walden-type inversion at the anomeric centre, both glucopyranosyl units were assigned the β-configuration. Full article

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

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8 pages, 1081 KB

Open AccessShort Note

1-(2-Aminophenyl)-3-(4-pyridyl)-3-hydroxy-1-propanone

by Yahaira Cuenú Ibargüen, Fernando Cuenú-Cabezas and Jovanny A. Gómez Castaño

Molbank 2026, 2026(2), M2155; https://doi.org/10.3390/M2155 - 25 Mar 2026

Viewed by 451

Abstract

This work reports the isolation and structural characterization of 1-(2-aminophenyl)-3-(4-pyridyl)-3-hydroxy-1-propanone (1), a β-hydroxyketone intermediate that crystallized unexpectedly during the base-catalyzed aldol condensation of 2-aminoacetophenone with pyridine-4-carbaldehyde, a reaction intended to afford the corresponding pyridyl chalcone (2). The formation of [...] Read more.

This work reports the isolation and structural characterization of 1-(2-aminophenyl)-3-(4-pyridyl)-3-hydroxy-1-propanone (1), a β-hydroxyketone intermediate that crystallized unexpectedly during the base-catalyzed aldol condensation of 2-aminoacetophenone with pyridine-4-carbaldehyde, a reaction intended to afford the corresponding pyridyl chalcone (2). The formation of (1) highlights the sensitivity of Claisen–Schmidt reactions to the electronic and steric features of the substrates and to the applied reaction conditions. Single-crystal X-ray diffraction unambiguously confirmed the molecular structure of (1), revealing a hydrogen-bonding network involving the amino, carbonyl, and β-hydroxyl functionalities. These interactions contribute to the solid-state stabilization of the β-hydroxyketone and hinder its dehydration to chalcone (2). The present results provide experimental insight into the mechanistic landscape of aldol condensations and emphasize the relevance of isolable intermediates as structurally defined precursors for further synthetic transformations. Full article

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

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7 pages, 704 KB

Open AccessShort Note

3a-Phenylhexahydropentalene-1,6-dione

by Yongyao Li, Hongtao Kong, Xiaoying Huang, Maxwell Ampomah-Wireko, Cedric Dzidzor Kodjo Amengor, En Zhang and Yihong Zhao

Molbank 2026, 2026(2), M2154; https://doi.org/10.3390/M2154 - 18 Mar 2026

Viewed by 403

Abstract

Bicyclo[3.3.0]skeleton is a common structural motif present in many natural products and pharmaceutical agents. Here we have synthesized a rigid 3a-arylhexahydropentalene-1,6-dione from cyclopent-2-en-1-one which is an easy and readily available starting material. Full article

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

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8 pages, 1978 KB

Open AccessCommunication

Naphthalene-Based Schiff Base Compounds

by Jocelyn Pradegan, Aurélien Crochet and Katharina M. Fromm

Molbank 2026, 2026(2), M2153; https://doi.org/10.3390/M2153 - 17 Mar 2026

Viewed by 533

Abstract

The synthesis of a salen-type ligand functionalized with naphthalene moieties, as well as its precursor, are reported. The compounds were characterized by ¹H and ¹³C NMR, ESI-MS spectrometry and single crystal X-ray diffraction. Full article

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5 pages, 586 KB

Open AccessShort Note

N-(3,4-Dimethoxyphenethyl)-2-propylpentanamide

by Diyana Dimitrova, Nikol Dimova, Dimitrina Velikova, Iliyan Ivanov, Dimitar Bojilov and Stanimir Manolov

Molbank 2026, 2026(2), M2152; https://doi.org/10.3390/M2152 - 13 Mar 2026

Viewed by 476

Abstract

In this Short Note type article, we report the synthesis of a new hybrid molecule, N-(3,4-dimethoxyphenethyl)-2-propylpentanamide, using a solvent-minimized mechanochemical method that provides a simple and efficient synthetic approach. The process achieved high yield. The compound was confirmed by melting-point analysis, ¹ [...] Read more.

In this Short Note type article, we report the synthesis of a new hybrid molecule, N-(3,4-dimethoxyphenethyl)-2-propylpentanamide, using a solvent-minimized mechanochemical method that provides a simple and efficient synthetic approach. The process achieved high yield. The compound was confirmed by melting-point analysis, ¹H and ¹³C NMR, IR spectroscopy, and mass spectrometry. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 1246 KB

Open AccessShort Note

Synthesis, Structural Characterization, and SHG Behavior of a Lanthanum/β-d-Fructose-Based Metal–Organic Framework

by Domenica Marabello and Paola Benzi

Molbank 2026, 2026(2), M2151; https://doi.org/10.3390/M2151 - 13 Mar 2026

Viewed by 345

Abstract

Interest in non-centrosymmetric crystalline materials exhibiting second harmonic generation (SHG) has increased due to their potential applications in optical sensing and biosensing. Saccharide-based metal complexes are particularly attractive systems, as chiral sugars can promote non-centrosymmetric crystal packing. In this work, a new lanthanum–β- [...] Read more.

Interest in non-centrosymmetric crystalline materials exhibiting second harmonic generation (SHG) has increased due to their potential applications in optical sensing and biosensing. Saccharide-based metal complexes are particularly attractive systems, as chiral sugars can promote non-centrosymmetric crystal packing. In this work, a new lanthanum–β-d-fructose compound, [La(C₆H₁₂O₆)(H₂O)₅]Cl₃ (LaFRUCl), was synthesized using a simple and low-cost method and characterized by single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group P2₁2₁2₁ and consists of infinite (La³⁺–fructose)_n chains extending along the [001] direction, forming a one-dimensional Metal–Organic Framework. The nonlinear optical response was evaluated using the Kurtz–Perry powder technique with a Nd:YAG laser (1064 nm) and compared to a sucrose reference. The measured SHG efficiency is comparable to that of previously reported alkaline earth metal–sugar analogs. While the compound’s SHG emission is significant, evaluation of its structural stability under aqueous or physiological conditions is be required before considering biological applications. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 422 KB

Open AccessCommunication

Synthesis of 3-[(2-Ethylhexyl)amino]-5-phenyl-4H-1,2,6-thiadiazin-4-one and 3-[(2-Ethylhexyl)amino]-5-[(4-oxo-5-phenyl-4H-1,2,6-thiadiazin-3-yl)amino]-4H-1,2,6-thiadiazin-4-one

by Andreas S. Kalogirou and Panayiotis A. Koutentis

Molbank 2026, 2026(2), M2150; https://doi.org/10.3390/M2150 - 11 Mar 2026

Viewed by 392

Abstract

Suzuki–Miyaura coupling of 3-chloro-5-[(2-ethylhexyl)amino]-4H-1,2,6-thiadiazin-4-one with phenylboronic acid, at ca. 100 °C, gave 3-[(2-ethylhexyl)amino]-5-phenyl-4H-1,2,6-thiadiazin-4-one in 69% yield. Another nucleophilic substitution reaction of 3-chloro-5-[(4-oxo-5-phenyl-4H-1,2,6-thiadiazin-3-yl)amino]-4H-1,2,6-thiadiazin-4-one with 2-ethylhexan-1-amine at ca. 100 °C gave 3-[(2-ethylhexyl)amino]-5-[(4-oxo-5-phenyl-4H-1,2,6-thiadiazin-3-yl)amino]-4H-1,2,6-thiadiazin-4-one in 93% yield. Full article

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

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7 pages, 679 KB

Open AccessCommunication

HAT-Initiated Fragmentation of 4-(Dimethylamino)-1-((3-methylbut-2-en-1-yl)oxy)-3-phenylbut-3-en-2-one

by Andrej Bogataj, Luka Ciber, Nejc Petek, Franc Požgan, Jurij Svete, Bogdan Štefane and Uroš Grošelj

Molbank 2026, 2026(2), M2149; https://doi.org/10.3390/M2149 - 11 Mar 2026

Viewed by 492

Abstract

An alkene-tethered enaminone 7 was synthesized in four steps from bromoacetic acid and 3,3-dimethylallyl alcohol. The enaminone was fully characterized, including UV-Vis spectra. TBADT-catalyzed HAT of the alkene-tethered enaminone initiated a fragmentation that yielded the literature-known phenylacetone-derived enaminone. Full article

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

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6 pages, 462 KB

Open AccessCommunication

Two-Stage Synthesis of 3-(4-Hydroxyphenyl)-1′,3′,6-trimethyl-2′H,3H,4H-spiro[furo[3,2-c]pyran-2,5′-pyrimidine]-2′,4,4′,6′(1′H,3′H)-tetraone

by Michail N. Elinson, Varvara M. Kalashnikova, Yuliya E. Ryzhkova and Oleg A. Rakitin

Molbank 2026, 2026(2), M2148; https://doi.org/10.3390/M2148 - 11 Mar 2026

Viewed by 449

Abstract

Spirocyclic compounds are experiencing a research surge due to their unique 3D structure, offering enhanced pharmacological, industrial, and material applications. They are increasingly used in medicinal chemistry to improve drug-like properties, such as solubility and target binding, and are also being utilized for [...] Read more.

Spirocyclic compounds are experiencing a research surge due to their unique 3D structure, offering enhanced pharmacological, industrial, and material applications. They are increasingly used in medicinal chemistry to improve drug-like properties, such as solubility and target binding, and are also being utilized for advanced material applications, including electronics and photonics. In this communication, 3-(4-hydroxyphenyl)-1′,3′,6-trimethyl-2′H,3H,4H-spiro[furo[3,2-c]pyran-2,5′-pyrimidine]-2′,4,4′,6′(1′H,3′H)-tetraone was prepared via a two-stage transformation including a tandem Knoevenagel–Michael reaction and NBS-induced cyclization. At the first stage, a previously unknown ionic scaffold, morpholin-4-ium 5-((4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)(4-hydroxyphenyl)methyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate was also isolated. Structures of the newly synthesized compounds were established by ¹H and ¹³C NMR, IR spectroscopy, high-resolution mass spectrometry, and elemental analysis. Full article

(This article belongs to the Collection Heterocycle Reactions)

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6 pages, 724 KB

Open AccessShort Note

N-(3,6-Dimethoxy-2-nitrophenyl)acetamide

by Lina A. Al-Dulaimi, Joseph C. Bear, Jeremy K. Cockcroft, Giuseppe Trigiante and Fawaz Aldabbagh

Molbank 2026, 2026(2), M2147; https://doi.org/10.3390/M2147 - 10 Mar 2026

Viewed by 408

Abstract

1,4-Dimethoxy-2,3-dinitrobenzene (1) reduction using sodium hydrosulfite resulted in 3,6-dimethoxybenzene-1,2-diamine (2) and 3,6-dimethoxy-2-nitroaniline (3) in 24% and 59% yields, respectively. Nitroaniline 3 was acetylated with acetyl chloride to give N-(3,6-dimethoxy-2-nitrophenyl)acetamide (4) in a 65% yield [...] Read more.

1,4-Dimethoxy-2,3-dinitrobenzene (1) reduction using sodium hydrosulfite resulted in 3,6-dimethoxybenzene-1,2-diamine (2) and 3,6-dimethoxy-2-nitroaniline (3) in 24% and 59% yields, respectively. Nitroaniline 3 was acetylated with acetyl chloride to give N-(3,6-dimethoxy-2-nitrophenyl)acetamide (4) in a 65% yield and with acetic anhydride to give N-acetyl-N-(3,6-dimethoxy-2-nitrophenyl)acetamide (5) in 78% yield. Novel compounds 4 and 5 were characterized by FT-IR, ¹H and ¹³C-NMR, and HRMS. The X-ray crystal structure of acetamide 4 is also presented. Full article

(This article belongs to the Collection Heterocycle Reactions)

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7 pages, 574 KB

Open AccessCommunication

Synthesis of 6,7-Dihydro-5H-pyrrolo[3,4-b]pyridin-5-one Derivatives

by Yong-Yao Li, Zhi-Hao Li, Xiao-Ying Huang, Maxwell Ampomah-Wireko, Cedric Dzidzor Kodjo Amengor, En Zhang and Yi-Hong Zhao

Molbank 2026, 2026(2), M2146; https://doi.org/10.3390/M2146 - 10 Mar 2026

Viewed by 529

Abstract

Owing to their distinctive physicochemical features, their structural analogues of benzene ring bioisosteres, and their strong affinity for biomacromolecules, pyridine derivatives function both as core structural scaffolds in pharmacologically active compounds and as versatile elements for optimizing key drug-like properties, such as water [...] Read more.

Owing to their distinctive physicochemical features, their structural analogues of benzene ring bioisosteres, and their strong affinity for biomacromolecules, pyridine derivatives function both as core structural scaffolds in pharmacologically active compounds and as versatile elements for optimizing key drug-like properties, such as water solubility, membrane permeability, and metabolic stability. In this study, we synthesized five pyridine-fused heterocyclic compounds using common synthetic intermediates as precursors. Full article

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

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8 pages, 1322 KB

Open AccessCommunication

Synthesis, Crystal Structure, and Properties of a Dinuclear Zinc(II) Complex Featuring a Bromo-Functionalized Semicarbazone Schiff Base Ligand

by Cuicui Wang, Jinhua Wang, Yunkai Zhang, Azura A. Rashid and Siew Kooi Ong

Molbank 2026, 2026(2), M2145; https://doi.org/10.3390/M2145 - 5 Mar 2026

Viewed by 446

Abstract

This study investigates the rational design of a dinuclear zinc(II) coordination polymer, (C₃₆H₃₄Br₂N₈O₄S₂Zn₂), to explore how halogen substitution and ligand choice modulate structural architecture, contributing to the development of [...] Read more.

This study investigates the rational design of a dinuclear zinc(II) coordination polymer, (C₃₆H₃₄Br₂N₈O₄S₂Zn₂), to explore how halogen substitution and ligand choice modulate structural architecture, contributing to the development of functional coordination polymers with tailored properties. The complex was synthesized from a bromo-substituted semicarbazone Schiff base ligand (L1) and a rigid bipyridine linker (L2) under solvothermal conditions, and its structure was elucidated using single-crystal X-ray diffraction (SCXRD), complemented by characterization via powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and infrared (IR) spectroscopy. Crystallographic analysis reveals that the complex crystallizes in the triclinic space group P-1, forming discrete dinuclear units where each Zn(II) center adopts a distorted square–pyramidal geometry; these units are extended into one-dimensional chains by bridging L2 ligands and further assembled into a three-dimensional supramolecular network through hydrogen-bonding interactions. PXRD confirms the high phase purity of the bulk material, TGA indicates notable thermal stability up to 130 °C, and IR spectroscopy validates the coordination modes and hydrogen-bonding network. This work elucidates the critical role of the bromo substituent and rigid ancillary ligands in modulating the solid-state structure of the zinc(II) complex. The revealed structure-directing principles provide a valuable reference for the rational design of functional coordination polymers. Full article

(This article belongs to the Section Structure Determination)

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7 pages, 458 KB

Open AccessCommunication

Synthesis of Ethyl 2-Amino-6-hydroxy-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate and Ethyl 6-(Acetyloxy)-2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate

by Andrii Yu. Myshastyi, Sergiy V. Vlasov, Hanna I. Severina, Georgiy G. Yakovenko and Andrii R. Khairulin

Molbank 2026, 2026(2), M2144; https://doi.org/10.3390/M2144 - 4 Mar 2026

Viewed by 938

Abstract

An effective one-step synthetic procedure for preparation of hydroxylated analogues of ethyl 2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate as novel promising multifunctional building blocks for drug discovery based on the Gewald procedure was developed. Full article

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

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Graphical abstract

6 pages, 1117 KB

Open AccessShort Note

(4S*,10aS*,11S*)-4-Hydroxy-2,7,7-trimethyl-11-(4-methylbenzoyl)-7,8-dihydro-10H-4,10a-methano[1,4]oxazino[3,4-d][1,3,5]thiadiazepine-5,10(4H)-dione

by Nikita A. Tretyakov and Andrey N. Maslivets

Molbank 2026, 2026(2), M2143; https://doi.org/10.3390/M2143 - 3 Mar 2026

Viewed by 460

Abstract

The reaction of 4,4-dimethyl-8-(4-methylbenzoyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-1,6,7-trione with thioacetamide in a 1:1 ratio when refluxed in dichloromethane gives (4S*,10aS*,11S*)-4-hydroxy-2,7,7-trimethyl-11-(4-methylbenzoyl)-7,8-dihydro-10H-4,10a-methano[1,4]oxazino[3,4-d][1,3,5]thiadiazepine-5,10(4H)-dione with a good yield. This compound was fully characterized. Full article

(This article belongs to the Section Structure Determination)

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Molbank, Volume 2026, Issue 2 (April 2026) – 24 articles

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