Molbank doi: 10.3390/M2215

Authors: Juan P. Montaño Andres F. Sánchez Rodrigo Abonia

The target (1E,4E)-1,5-bis(2,4-dichlorophenyl)penta-1,4-dien-3-one oxime 4 was prepared in good yield, as a key aza-precursor for the Nazarov cyclization, through a two-step sequence in this study. Initially, the starting divinyl ketone 1a was obtained via a Claisen–Schmidt condensation reaction between 2,4-dichlorobenzaldehyde 3 and acetone in the presence of aqueous 20% NaOH. Subsequently, treating 1a with hydroxylamine hydrochloride under thermal conditions resulted in the expected oxime in excellent yield, and its structure was confirmed by analytic and spectroscopic techniques.

Molbank doi: 10.3390/M2214

Authors: Anastasiya S. Yushkova Ekaterina A. Knyazeva Oleg A. Rakitin

Compounds containing electron-withdrawing dicyanopyrazine and 1,2,5-chalcogenadiazole fragments are promising for the design of magnetic and optoelectronic materials. In this paper, bis([1,2,5]thiadiazolo)[3,4-f:3′,4′-h]quinoxaline-8,9-dicarbonitrile was prepared via Körner–Hinsberg condensation of benzo[1,2-c:3,4-c′]bis([1,2,5]thiadiazole)-4,5-dione with 2,3-diaminomaleonitrile in the presence of catalytic amounts of TsOH in refluxing ethanol. The structure of the newly synthesized compound was established via elemental analysis, mass spectrometry, 13C NMR, and IR spectroscopy.

Molbank doi: 10.3390/M2213

Authors: Guo-Li Li Zhi-Dong Yu Na Gao Hong-Ying Yang Yi-Lin He Tong Shen

Gymnaconitum gymnandrum, a Tibetan medicinal herb, is distributed across high-altitude regions of China. Despite its high toxicity, it exhibits analgesic, anti-inflammatory, antitumor, and other pharmacological activities. It is used topically for skin conditions and orally for rheumatism. Its main bioactive components are alkaloids. A new organic amine alkaloid has been isolated from the plant and structurally identified using HRMS, NMR, and X-ray diffraction.

Molbank doi: 10.3390/M2212

Authors: Dominika Kuceł Jarosław Sobstyl Serhii Holota Dmytro Khylyuk

A novel spiro[indoline-3,2′-thiazolidine]-2,4′-dione derivative incorporating 3-chloro-4-fluorophenyl and 6-methoxypyridin-3-yl fragments was synthesized and characterized. The synthetic route involved a two-step procedure, including the preparation of the spirocyclic scaffold via cyclocondensation of 5-fluoroisatin with 3-chloro-4-fluoroaniline in the presence of mercaptoacetic acid, followed by Knoevenagel condensation with 6-methoxypyridine-3-carbaldehyde. The reactions were carried out under reflux conditions and afforded the desired product in a satisfactory yield after purification by recrystallization. The structure of the synthesized compound was confirmed by 1H and 13C NMR spectroscopy, LC–MS analysis, FT-IR and elemental analysis, all of which were consistent with the proposed molecular structure. The presence of multiple pharmacologically relevant heterocyclic motifs within a single framework suggests that this compound may serve as a useful scaffold for further biological evaluation.

Molbank doi: 10.3390/M2211

Authors: Claudio Maestri Mattia Lopresti Ivana Miletto Attila Benyei Marzia Petreti Luisa Zangirolami Camilla Cavallotti Giovanni B. Giovenzana

Levofloxacin is an antibiotic belonging to the fluoroquinolone family. N-Demethyllevofloxacin, a metabolite and an impurity of levofloxacin, features a secondary amine that is susceptible to N-nitrosation, raising concerns about the formation of a potentially toxic nitrosamine. The corresponding N-nitrosamine was synthesized in two steps and characterized using HRMS, NMR spectroscopy, IR spectroscopy, UV absorption and emission spectroscopies and powder X-ray diffraction. This work provides a reliable reference for the quantitation and control of nitrosamine impurities associated with levofloxacin in chemical and pharmaceutical contexts.

Molbank doi: 10.3390/M2210

Authors: Andrea Patrizia Falanga Maria Marzano Stefano D’Errico

We have recently demonstrated that the pendant tert-butyldiphenylsilyl (TBDPS) groups in the short oligonucleotides TBDPS-5′-CG-3′-3′-GC-5′-TBDPS and TBDPS-5′-CGG-3′-3′-GGC-5′-TBDPS promoted the formation of new lipophilic and stable tetramolecular G-quadruplexes (GQs). Encouraged by these findings, we sought to investigate the effect of alternative lipophilic substituents at the flanking cytidine residues on GQ formation and properties. Herein, we reported on the synthesis and spectroscopic characterization of the new N4-benzoyl-N3-benzyl-2′-deoxycytidine, which was obtained during our attempts to synthesize N4-benzoyl-5′-O-benzyl-2′-deoxycytidine.

Molbank doi: 10.3390/M2209

Authors: Augusto Rivera Jaime Ríos-Motta Diego Quiroga

The reaction of 8-hydroxyquinoline and (2R,7R,11S,16S)-1,8,10,17-tetraazapentacyclo [8.8.1.1.8,170.2,70.11,16]icosane under Mannich-type conditions afforded a new quinoline-functionalized diazabicyclic derivative in 27% yield. The structure of the product was established by FT-IR, 1H and 13C NMR, HSQC, HMBC, and ESI-MS analyses, which confirmed the connectivity between the two quinoline units and the perhydrobenzimidazole heterocyclic fragment. The conformational strain of the perhydroimidazolidine fragment prevents the rearrangement pathway previously reported for related systems, such as cyclic aminal 1,3,6,8-tetraazatricyclo [4.4.1.13,8]dodecane (TATD), leading to a different reaction outcome. The results demonstrate that the conformationally constrained aminal exhibits reactivity distinct from that reported for TATD-derived systems, providing new insight into the behavior of cyclic aminals in Mannich-type reactions.

Molbank doi: 10.3390/M2208

Authors: Ghaffar Pasdar Abdolhamid Bamoniri Bi Bi Fatemeh Mirjalili

In the original publication [...]

Molbank doi: 10.3390/M2207

Authors: Domenica Marabello Paola Benzi Elena Cariati

1,2-Dichloroethane was found to stabilize the lattice of chloride anions associated with the protonated porphyrin of formula [C44H32N4]Cl2·4C2H4Cl2. The synthesis and X-ray characterization of this compound are reported and compared with analogous solvates. The porphyrin macrocycle displays a distorted saddle conformation, with chloride anions positioned above and below the mean plane of the ring, further surrounded by two dichloroethane molecules that stabilize the crystal packing. The Second-Harmonic Generation response was evaluated using the Kurtz–Perry powder technique with a ND:YAG laser (1064 nm).

Molbank doi: 10.3390/M2206

Authors: Jessica A. Perez-Rangel Alejandro Islas-Jácome Luis Chacón-García Armando Talavera-Alemán Carlos J. Cortés-García

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).

Molbank doi: 10.3390/M2205

Authors: Kimiya Sukegawa Masaki Yamamura Tatsuya Nabeshima

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.

Molbank doi: 10.3390/M2204

Authors: Maksim A. Valiarovskii Alexander V. Vorob’ev Anastasiya V. Agafonova Mikhail S. Novikov

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.

Molbank doi: 10.3390/M2203

Authors: Yuki Itabashi Kei Ohkubo

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.

Molbank doi: 10.3390/M2202

Authors: Mingguang Zhang Siyu Hao Baiyang Mao Yongxu Piao

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).

Molbank doi: 10.3390/M2201

Authors: Yordanka B. Ivanova Daniel Y. Yordanov Ognyan I. Petrov

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.

Molbank doi: 10.3390/M2200

Authors: Lei Gao Li Xu Zheng Zhang Jinchang Zhang Diangang Bai Xiangrong Wang Yue Zhang

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.

Molbank doi: 10.3390/M2199

Authors: Miku Yoshida Masafumi Yasunami Ryuta Sekiguchi Shunji Ito Taku Shoji

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.

Molbank doi: 10.3390/M2198

Authors: Inès Jacquet Romain Paoli-Lombardo Caroline Castera-Ducros Patrice Vanelle Nicolas Primas

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.

Molbank doi: 10.3390/M2197

Authors: Xiqiang Gao Jung Hoon Park Bohua Lu Jinxing Zhai Xiaoyi Sun Yuanhui Wang Lak Shin Jeong Qiang Wang

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.

Molbank doi: 10.3390/M2196

Authors: Kirsten S. Graham Aidan P. McKay David B. Cordes Brian A. Chalmers

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.

Molbank doi: 10.3390/M2195

Authors: Brian A. Chalmers David B. Cordes Tomas Lebl Aidan P. McKay Iain L. J. Patterson Nadiia Vladymyrova Iain A. Smellie

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.

Molbank doi: 10.3390/M2194

Authors: Helen M. Sheldrake

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.

Molbank doi: 10.3390/M2193

Authors: Xiangrong Zhang Dingkuo Liu Fang Liu Cheng Yang Jingjing Gao Chunfeng Xie

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.

Molbank doi: 10.3390/M2192

Authors: Yue Zhang Xiangrong Wang Zhihan Liu Zheng Zhang Xiaoxu Tan Lei Gao

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.

Molbank doi: 10.3390/M2191

Authors: Maha M. Alotaibi Md Abdul Goni Eric Reinheimer Tasneem A. Siddiquee

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.

Molbank doi: 10.3390/M2190

Authors: Tiffany L. Chen Manisha Sharma Nicholas E. Leadbeater

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

Molbank doi: 10.3390/M2189

Authors: Anastasia R. Kovrizhina Andrei I. Khlebnikov

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.

Molbank doi: 10.3390/M2188

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

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.

Molbank doi: 10.3390/M2187

Authors: Na Gao Guo-Li Li Lei Wang Hong-Ying Yang Yi-Lin He Tong Shen

The Delphinium albocoeruleum Maxim is a perennial herbaceous plant of the Ranunculaceae family, genus Delphinium. It typically grows in well-drained alpine meadows or shrublands at elevations of 2500–4000 m, which shapes the species’ unique environmental adaptation mechanism and endows it with high medicinal value. There are a few reports on the chemical constituents and biological activities of this plant. Therefore, this study focuses on the chemical constituents of the plant in order to discover structurally novel alkaloids. This paper reports on the isolation and structural characterization, using HRMS and 1D and 2D NMR, of a new alkaloid that came from the plant.

Molbank doi: 10.3390/M2186

Authors: Diana Becerra Mario A. Macías Juan-Carlos Castillo

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.

Molbank doi: 10.3390/M2185

Authors: Catalina Hoyos-Orozco Ericsson Coy-Barrera Diego Quiroga

Imidazolidin-2-thiones are versatile sulfur-containing heterocycles with broad biological relevance. The synthesis of (3aR,7aR)-1,3-bis(4-aminobenzyl)octahydro-2H-benzo[d]imidazole-2-thione (an imidazolidin-2-thione derivative) from trans-(R, R)-diaminocyclohexane is presented via a three-step sequence: formation of a Schiff base from 1,2-diamine and 4-nitrobenzaldehyde, followed by reduction with NaBH4; thiocarbonylation under microwave irradiation (MW) to generate the imidazolidin-2-thione core; and reduction of the nitro substituents to amines using an iron/CaCl2 system. The structure of the final compound was confirmed by detailed 1H and 13C NMR analyses, demonstrating the preservation of the bicyclic backbone and the successful conversion of the nitro functional group. The overall yield of the sequence was 28%, with the reduction of the nitro group identified as the rate-limiting step. This protocol represents a viable synthetic strategy for obtaining functionalized imidazolidin-2-thiones useful for the development of novel bioactive sulfur-containing heterocycles.

Molbank doi: 10.3390/M2184

Authors: Yuhan Xie Nayara Macêdo Peixoto Araujo Stanislau Bogusz Junior Deepa Alex Paolo Coghi

In this report, we describe the synthesis of two new celastrol derivatives featuring aryl-substituted 1,2,3-triazole fragments attached to the celastrol scaffold via an ester linkage. The target compounds, incorporating 4-methoxyphenyl and p-tert-butylphenyl groups, were characterized by 1H and 13C NMR spectroscopy, FTIR, UV-Vis, HRMS, melting point determination, and specific rotation measurements.

Molbank doi: 10.3390/M2183

Authors: Yu-En Huang Shigekazu Ito

Fluoroalkyl-substituted organoboron compounds are valuable building blocks for organic synthesis and for the development of functional molecules in medicinal chemistry, agrochemicals, and materials science. Building on our previous work on difluoromethyl-substituted borates, we report the synthesis and structural characterization of trifluoromethylated borates, 2-aryl-4,4,5,5-tetramethyl-2-(trifluoromethyl)-1,3,2-dioxaborolan-2-uide salts ([pinB(Aryl)CF3]−). Treatment of pinB–Aryl boronates (pinB = 4,4,5,5-tetramethyl-1,3,2-dioxaborolane) with trimethyl(trifluoromethyl)silane (Ruppert–Prakash reagent) in the presence of potassium tert-butoxide and 18-crown-6 ether (18-C-6) afforded the corresponding trifluoromethylated borates as isolable crystalline compounds. Compared with the related difluoromethylated borates, the CF3 substituent increases the tendency of [pinB(Aryl)CF3]− to exhibit hygroscopic behavior, as supported by a hydrated crystal structure and the formation of a hygroscopic product. The isolable trifluoromethylborates can serve as reservoirs of electrophilic trifluoromethyl radicals upon oxidation.

Molbank doi: 10.3390/M2182

Authors: Nathan Long Emanuela Paval Joseph C. Bear Jeremy K. Cockcroft Stephen P. Wren

The title compound, 3-(diphenylamino)-4-ethoxycyclobut-3-ene-1,2-dione (6), was prepared by reaction of diphenylamine (2) with diethyl squarate (DES; 5) as part of our ongoing studies on monosquarate-amides. Following purification and recrystallisation, the product was isolated as a green crystalline solid. Its structure was established by spectroscopic methods, including FTIR, 1H NMR, 13C NMR and HRMS, and was unambiguously confirmed by single-crystal X-ray diffraction. This work provides access to a previously unreported diphenylamino-substituted squaric acid derivative.

Molbank doi: 10.3390/M2181

Authors: Ghaffar Pasdar Abdolhamid Bamoniri Bi Bi Fatemeh Mirjalili

A novel bio-capable method has been implemented for the synthesis of newly substituted derivatives of perimidine using Fe3O4@nano-cellulose/Ti(IV) as a magnetic, sustainable, and eco-friendly Lewis acid nanocatalyst. The catalyst was thoroughly characterized by XRD, FESEM, and TGA analyses, confirming its crystalline structure, uniform nanoscale morphology, and high thermal stability. The reaction proceeded smoothly in eco-friendly solvents, providing outstanding yields under mild and rapid conditions, especially with ultrasonics. The catalyst, derived from renewable materials, exhibited remarkable activity, easy magnetic recovery, and excellent reusability over several cycles without significant loss of efficiency. Spectral characterization, IR, 1H NMR, 13C NMR, 19F NMR, and HRMS analyses verified that perimidine derivatives were synthesized properly. This sustainable and efficient approach demonstrates the prospect of green Lewis acid nanocatalysts for the sustainable synthesis of valuable heterocyclic compounds.

Molbank doi: 10.3390/M2180

Authors: Munishama Gowda Yenagunte Narayanaswamy Sujeet Kumar Siddamsetty Ramachandra Setty Basavaraj Metikurki Chaluvaraju Kalamuddanadoddi Chaluvegowda

In the present work, we synthesize 2-(4-allyl-2-methoxyphenoxy)-1-(4-phenylpiperazin-1-yl)ethan-1-one, a semisynthetic derivative of the natural product eugenol. The compound was synthesized via a three-step synthetic pathway involving esterification, hydrolysis, and subsequent coupling with 4-phenylpiperazine, as confirmed by FTIR, 1H NMR, 13C NMR, and mass spectrometric data.

Molbank doi: 10.3390/M2179

Authors: Sarah Stoppe Marianne Hahn Martin Dauner Frank Bordusa

Rhodamine 110 (R110) peptide conjugates are widely used fluorogenic substrates in proteolytic assays; however, their inherent symmetry results in two identical hydrolysis sites, complicating their application as well-defined substrates. Here, we report a preparative enzymatic strategy for the desymmetrization of the symmetric derivative (Acetyl-Leu-Pro-Lys)2-R110 using the bovine trypsin variant D189S. Due to pronounced differences in the rates of the two sequential hydrolysis steps, a mono-substituted intermediate accumulates under controlled reaction conditions. On a preparative scale, Acetyl-Leu-Pro-Lys-R110 was generated by partial hydrolysis and isolated by preparative HPLC in 28.8% yield and 95.8% purity. The structure of the asymmetric product was fully characterized by NMR and high-resolution mass spectrometry. This work demonstrates that selective enzymatic hydrolysis provides a simple and effective preparative route to asymmetric Rhodamine 110 derivatives, offering a practical alternative to conventional multistep synthetic approaches and enabling improved substrate design for kinetic studies.

Molbank doi: 10.3390/M2178

Authors: Itamar Gonçalves Aloir Merlo Bruna Batistel Leonardo Rossner Wbatuba Henrique de Aguiar Mello

This study addresses the synthesis of a new liquid crystalline compound featuring a 3,5-disubstituted isoxazoline and a 1,3-dioxolan-2-one ring, and renewable aromatic building blocks derived from vanilin and benzoic acid. The target compound was synthesized through a multistep synthetic route involving alkylation, esterification, oxime formation, and a 1,3-dipolar cycloaddition reaction. The synthesized compound, 2-methoxy-4-[5-(2-oxo-1,3-dioxolan-4-yl)-4,5-dihydroisoxazol-3-yl]phenyl 4-n-decyloxybenzoate, was isolated and fully characterized by spectroscopic techniques. Liquid crystal behavior was evaluated by DSC and POM. The monotropic mesomorphic behavior of the title compound was dictated by the interplay between molecular architecture and intermolecular organization, with the methoxy substituent and the 1,3-dioxolan-2-one ring critically influencing phase stability and texture morphology. These findings suggest a structure–property relationship and guide ongoing synthetic optimization toward achieving a stable enantiotropic liquid-crystalline phase and further ion-conduction experiments.

Molbank doi: 10.3390/M2177

Authors: Savina Stoyanova Milen G. Bogdanov

The formation of side products is often unavoidable in organic synthesis; however, analyzing these secondary species provides practical insights into reaction pathways, mechanisms, and competing processes. This understanding is essential for optimizing reaction conditions, increasing product yields, and improving overall safety and efficiency. Additionally, side products can sometimes reveal unexpected molecular structures with valuable properties. In this study, we present the characterization of a compound that formed as a side product in a modified Pictet-Spengler reaction. The molecular structure of 2,2′-(methylenebis(3,4-dimethoxy-6,1-phenylene))diacetic acid was elucidated using a combination of NMR, FTIR and UV–Vis spectroscopic techniques, as well as HRMS analysis.

Molbank doi: 10.3390/M2176

Authors: Sara Braun Anke Schwarzer Monika Mazik

4-Methyl- (1) and 4-ethyl-8-hydroxyquinoline (2) crystallize from a mixture of diethyl ether and chloroform in the triclinic space group P1¯. X-ray analysis reveals that both compounds form discrete molecular dimers stabilized by intermolecular O-H∙∙∙N and C-H∙∙∙O hydrogen bonds, resulting in R22(5) cyclic synthons. This pattern of hydrogen bonds is further stabilized by intramolecular O-H∙∙∙N bonds so that the quinoline nitrogen atom acts as a bifurcated binding site. The dimers exhibit a planar geometry and arrange into layer-like structures held together by π∙∙∙π stacking and van der Waals forces. While the fundamental bonding motifs are similar, the increased steric demand of the ethyl group in compound 2 induces a shift in the crystallographic orientation of the layers and alters the degree of π-overlap compared to the methyl-substituted analogue 1.

Molbank doi: 10.3390/M2175

Authors: Sonia Berenguel-Gómez Irene Moreno-Gutiérrez Jenifer Acien-García Manuel Muñoz-Dorado Míriam Álvarez-Corral Ignacio Rodríguez-García

A new tert-butyldimethylsilyl-protected polyoxygenated chalcone was prepared by Claisen–Schmidt condensation of suitably protected acetophenone and benzaldehyde derivatives. Treatment of this chalcone with m-chloroperbenzoic acid (mCPBA) afforded β-(3-chlorobenzoyloxy)-α-hydroxyketone 5, which was fully characterized by spectroscopic methods. The structure of 5 is consistent with initial epoxidation of the enone double bond followed by in situ nucleophilic opening of the transient epoxide by m-chlorobenzoate generated in the reaction medium. This work reports the preparation of the chalcone precursor and the characterization of the unexpected oxidation product 5.

Molbank doi: 10.3390/M2174

Authors: Tiffany L. Chen Manisha Sharma Nicholas E. Leadbeater

The conversion of 2,5-difluorobenzylamine to N-(2,5-difluorobenzylidene)-1-(2,5-difluorobenzyl)methanimine using an oxoammonium salt bearing the nitrate anion is reported. The reaction is operationally simple, and the product is obtained with good yield.

Molbank doi: 10.3390/M2173

Authors: Mikhail A. Panfilov Alexey Yu. Vorob’ev Alexander E. Moskalensky

The BODIPY core has emerged as a versatile scaffold for the design of photoremovable protecting groups (PPGs). Herein, we report the synthesis of a novel BODIPY–epinephrine conjugate linked via a carbamate moiety, enabling light-triggered release of the active compound (epinephrine, also known as adrenaline). The structure of the obtained product was confirmed by 1H and M 13C NMR spectroscopy as well as high-resolution mass spectrometry (HRMS). The described conjugate represents a potential tool for the photoactivated modulation of biologically relevant processes.

Molbank doi: 10.3390/M2172

Authors: Yusen Wang Jian Lv Yukun Qin

A novel nitrogen-containing heterocyclic compound, 4-(6-Chloropyridin-3-yl)-6-cyclopropylpyrimidin-2-amine, was designed and synthesized using 6-chloropyridin-3-aldehyde and cyclopropyl methyl ketone as starting materials. The structure of the target compound was characterized by 1H NMR, 13C NMR and HRMS, and the spectral data were consistent with the expected structure, confirming the correctness of the product.

Molbank doi: 10.3390/M2171

Authors: Peter Mayo Sumudu Deepa Abeysekera

The compound (Z)-6-heneicosen-11-one, a possible pheromone component of the hickory tussock moth, Lophocampa caryae, and a known pheromone component of the Douglas fir tussock moth, Orgyia pseudotsugata, was synthesized by a new four-step procedure with a 39% overall yield and a six-step procedure incorporating a protecting group with a 28% overall yield. This new synthesis is comparable to other similar syntheses for this molecule in the literature.

Molbank doi: 10.3390/M2170

Authors: Pascal Pigeon

The ferrocidiphenol family brings together anticancer molecules featuring a [ferrocene-alkene-(p-phenol)2] motif that can form upon oxidation a quinone methide metabolite targeting cellular proteins. Adding an imide group (imido-ferrocidiphenol) dramatically enhanced the anticancer activity of ferrocidiphenol. We aimed to explore whether molecules with two ferrociphenol motifs connected by bisimide moieties could provide even more effective compounds. Using amino-ferrocidiphenol and commercial bisanhydrides at reflux, for the first time, three symmetrical and bent bis(imido-ferrocidiphenols) were synthesized, with moderate yields, and characterized. However, these compounds were insoluble in most common organic solvents and unstable. This likely explains why their anticancer activity was nil.

Molbank doi: 10.3390/M2169

Authors: José María Peña-Martínez Jesús Alberto Rojas Morales Luis Ramiro Caso-Vargas Elizabeth Bautista-Rodríguez Joel L. Terán Alan Carrasco-Carballo

The synthesis of three novel, valuable bioconjugates obtained by coupling cholesterol bromoacetate with pyridine derivatives via an SN2 reaction was successfully carried out. Each of the products was fully characterized by magnetic nuclear resonance (1H, 13C, APT, 1H−1H COSY, 1H–13C HMBC, 1H–13C HSQC), infrared spectroscopy (IR), and high-resolution mass spectrometry (HRMS).

Molbank doi: 10.3390/M2168

Authors: Rumen Lyapchev Maria Ivanova Iskra Z. Koleva Dimitar Shandurkov

A new compound, 2-(2-methoxyphenyl)-4-methyl-6-nitroquinoline, was obtained via Suzuki reaction. An unexpected side product, 2-(2-methoxyphenyl)-4-methylquinolin-6-amine, was isolated. The structures of the novel compounds were confirmed by 1H, 13C and 2D-NMR. Their optical properties were also studied.

Molbank doi: 10.3390/M2167

Authors: Alan Aguilar-Aguilar Ángel Palillero-Cisneros Félix May-Moreno Jorge R. Juarez-Posadas Joel L. Terán David M. Aparicio

Herein, starting from (R)-(+)-α-methylbenzylamine, we report an efficient synthesis and full characterization of a new (R)-3-(1-hydroxyethylidene)-1-(1-phenylethyl)piperidine-2,4-dione, a new tetramic acid analog. The key steps involved a non-classical Corey–Chaykovsky intramolecular cyclization reaction to access the corresponding zwitterion, followed by a sequential desulfurization/reduction and condensation procedure. The titled product was obtained in five steps, and the desired product 7 with an overall 58% yield.

Molbank doi: 10.3390/M2166

Authors: Matevž Schweiger Luka Ciber Nejc Petek Franc Požgan Jurij Svete Bogdan Štefane Uroš Grošelj

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.

Molbank doi: 10.3390/M2165

Authors: Julia I. Pavlenko Mikhail S. Novikov Anastasiya V. Agafonova

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.

Molbank doi: 10.3390/M2164

Authors: Yuki Itabashi Kei Ohkubo

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.

Molbank doi: 10.3390/M2163

Authors: Yordan Stremski Maria Bachvarova Stela Statkova-Abeghe Plamen Angelov

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.

Molbank doi: 10.3390/M2162

Authors: Richard M. Beteck Lesetja J. Legoabe

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.

Molbank doi: 10.3390/M2161

Authors: Maria Annunziata M. Capozzi Cosimo Cardellicchio

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.

Molbank doi: 10.3390/M2160

Authors: Eder Y. Nolasco-Terrón David Gómez-Colín Nelly González-Rivas Diego Martínez-Otero Erick Cuevas-Yañez

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.

Molbank doi: 10.3390/M2159

Authors: Roderick Abdilla Stefano Volpi Alessandro Casnati Maria A. Cardona Ruben Gatt

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.

Molbank doi: 10.3390/M2158

Authors: Desita Triana Aziz Resky Nugraha Marwah Wirda Ningsih Zetryana Puteri Tachrim Yuta Murai Makoto Hashimoto

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.

Molbank doi: 10.3390/M2157

Authors: Hye Jin Kim Kye Jung Shin Khin Myo Htwe Kee Dong Yoon

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).

Molbank doi: 10.3390/M2156

Authors: Sara Ghazi Mohamed Touaibia

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.

Molbank doi: 10.3390/M2155

Authors: Yahaira Cuenú Ibargüen Fernando Cuenú-Cabezas Jovanny A. Gómez Castaño

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.

Molbank doi: 10.3390/M2154

Authors: Yongyao Li Hongtao Kong Xiaoying Huang Maxwell Ampomah-Wireko Cedric Dzidzor Kodjo Amengor En Zhang Yihong Zhao

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.

Molbank doi: 10.3390/M2153

Authors: Jocelyn Pradegan Aurélien Crochet Katharina M. Fromm

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.

Molbank doi: 10.3390/M2152

Authors: Diyana Dimitrova Nikol Dimova Dimitrina Velikova Iliyan Ivanov Dimitar Bojilov Stanimir Manolov

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.

Molbank doi: 10.3390/M2151

Authors: Domenica Marabello Paola Benzi

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.

Molbank doi: 10.3390/M2150

Authors: Andreas S. Kalogirou Panayiotis A. Koutentis

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.

Molbank doi: 10.3390/M2149

Authors: Andrej Bogataj Luka Ciber Nejc Petek Franc Požgan Jurij Svete Bogdan Štefane Uroš Grošelj

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.

Molbank doi: 10.3390/M2148

Authors: Michail N. Elinson Varvara M. Kalashnikova Yuliya E. Ryzhkova Oleg A. Rakitin

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.

Molbank doi: 10.3390/M2147

Authors: Lina A. Al-Dulaimi Joseph C. Bear Jeremy K. Cockcroft Giuseppe Trigiante Fawaz Aldabbagh

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.

Molbank doi: 10.3390/M2146

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

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.

Molbank doi: 10.3390/M2145

Authors: Cuicui Wang Jinhua Wang Yunkai Zhang Azura A. Rashid Siew Kooi Ong

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.

Molbank doi: 10.3390/M2144

Authors: Andrii Yu. Myshastyi Sergiy V. Vlasov Hanna I. Severina Georgiy G. Yakovenko Andrii R. Khairulin

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.

Molbank doi: 10.3390/M2143

Authors: Nikita A. Tretyakov Andrey N. Maslivets

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.

Molbank doi: 10.3390/M2142

Authors: Dmitry V. Osipov Pavel E. Krasnikov Vitaly A. Osyanin

A DABCO-catalyzed one-pot synthesis of a novel pentacyclic heterocycle featuring an unprecedented benzo[4,5]imidazo[1,2-a]chromeno[3,2-e]pyridine scaffold from 2-(cyanomethyl)benzimidazole and 3-trifluoroacetyl-4-phenyl-4H-chromene has been developed. This hybrid architecture merges three privileged pharmacophores—benzimidazole, chromene, and pyridine—into a rigid, nearly planar π-extended system decorated with trifluoromethyl and nitrile groups. The structure of 8-phenyl-13a-(trifluoromethyl)-13aH-benzo[4,5]imidazo[1,2-a]chromeno[3,2-e]pyridine-6-carbonitrile was unambiguously confirmed through NMR spectroscopy and X-ray diffraction analysis. A plausible mechanism involves Michael addition, hemiaminal formation, ring opening, recyclization, and oxidation.

Molbank doi: 10.3390/M2141

Authors: Jorge Trilleras Efraín Polo-Cuadrado Jairo Quiroga

The synthesis of methyl (E)-3-(2-amino-4-chloro-6-morpholinopyrimidin-5-yl)acrylate 3 was accomplished using a Schlosser-modified Wittig reaction. Complete 1H and 13C NMR signal assignments confirm the formation of E-alkene.

Molbank doi: 10.3390/M2140

Authors: Yuhan Xie Alessandra Gianoncelli Imran Khan Giovanni Ribaudo Paolo Coghi

In this report, we describe the synthesis and full spectroscopic characterization of a previously unreported podophyllotoxin (PTOX) analogue bearing a second 3,4,5-trimethoxyphenyl (TMP) unit at the C-4 position through an ester linkage. This dual-TMP PTOX derivative is obtained from a brominated PTOX intermediate. In this precursor, the bromine atom is located on the TMP aromatic ring at the 2′-position. The new compound was fully characterized by proton (1H), carbon-13 (13C), heteronuclear single-quantum coherence (HSQC), and distortionless enhancement by polarization transfer (DEPT) NMR spectroscopy. Ultraviolet–visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, mass spectrometry and elemental analysis were also performed to confirm the structure and purity of the synthesized ester derivative.

Molbank doi: 10.3390/M2139

Authors: Laurence J. Taylor Philip Pickett David B. Cordes Petr Kilian

Peri-substituted bis(tertiary) phosphine-arsine Acenap(PiPr2)(As(SPh)Ph) (4, Acenap = acenaphthene-5,6-diyl) was synthesized by the reaction of the chloroarsine (PiPr2)(AsPhCl) with PhSLi. The X-ray crystal structure of this compound reveals an intramolecular P∙∙∙As–Cl pnictogen bond, with the phosphorus lone pair donating into the As–S σ* orbital.

Molbank doi: 10.3390/M2138

Authors: Thomas Gelbrich Johanna Freilinger Gabriel Partl Herwig Schottenberger Volker Kahlenberg Jan Back Sven Nerdinger

Vinylimidazolium salts constitute a highly relevant class of polymerizable heterocycles, especially in the field of so-called polymer ionic liquids (PILs), and they are frequently used as components of polyelectrolytes. Therefore, crystallographic characterizations, in particular studies of charge distribution and conformational features, can provide fundamental insights concerning ion–ion and ion–dipole interactions. The structure of the title compound [1046127-79-0] has the space group symmetry P21/c. Its asymmetric unit contains one formula unit, consisting of two bromide anions and the halves of two cation moieties. The cation units possess inversion symmetry, and their C6H12 chains adopt an all-trans conformation.

Molbank doi: 10.3390/M2137

Authors: Vincenzo Piccialli Nicola Borbone Monica Terracciano

As a part of an SAR study aimed at testing the antitumor activity of some C15 acetogenins related to mycalin A, we report here the synthesis of the C-1 debromo-derivative of laurenciallene, a substance recently isolated from the red alga Laurencia obtusa. This new substance has been obtained by the selective, reductive debromination of the terminal bromoallene moiety of laurenciallene with Zn/AcOH. Its structure has been fully characterized by spectral methods, including 2D-NMR spectra.

Molbank doi: 10.3390/M2136

Authors: Qing-Qing Wan Zhi-Cheng Fu

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.

Molbank doi: 10.3390/M2135

Authors: Mihaela Cristea Sergiu Shova Marcel Mirel Popa Florea Dumitrascu

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.

Molbank doi: 10.3390/M2134

Authors: Ilia A. Pilipenko Olga Yu. Ozerova Oleg P. Demidov Ruslan I. Baichurin Oussama A. Mammeri Sergey V. Makarenko

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.

Molbank doi: 10.3390/M2133

Authors: Mara Plotniece Krista Arule Karlis Pajuste Aiva Plotniece Arkadij Sobolev

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.

Molbank doi: 10.3390/M2132

Authors: Diyana Dimitrova Tsvetelina Marinova Reni Bozhanova Iliyan Ivanov Dimitar Bojilov Gabriel Marc Stanimir Manolov

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.

Molbank doi: 10.3390/M2131

Authors: Silvia Rizzato Massimo Moret

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.

Molbank doi: 10.3390/M2130

Authors: Denis A. Tiunov Victor A. Tafeenko Alexander V. Kurkin

(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).

Molbank doi: 10.3390/M2129

Authors: Abderrahim Khatyr Isabelle Jourdain Michael Knorr Carsten Strohmann Tobias Schrimpf

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.

Molbank doi: 10.3390/M2128

Authors: Young Hee Lee Jae-Kyung Jung

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).

Molbank doi: 10.3390/M2127

Authors: Adriana Grozav Cristina Azarov Gabriel Marc Adrian Pîrnău Stanimir Manolov Ovidiu Oniga Ovidiu Crișan

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.

Molbank doi: 10.3390/M2126

Authors: Navaratnarajah Kuganathan Tharmarajah Manoranjan

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.

Molbank doi: 10.3390/M2125

Authors: Andreas S. Kalogirou Panayiotis A. Koutentis

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.

Molbank doi: 10.3390/M2124

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

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.

Molbank doi: 10.3390/M2123

Authors: Diyana Dimitrova Iliyan Ivanov Simona Ilieva Ivelina Cherneva Dimitar Bojilov Stanimir Manolov

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.

Molbank doi: 10.3390/M2122

Authors: Roman A. Irgashev Alexander S. Steparuk Gennady L. Rusinov Ildar R. Sayarov Alexey E. Aleksandrov Alexey R. Tameev

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 (λem = 565 nm, ΦF = 0.81, τ = 11.41 ns), which is strongly quenched in the solid state (ΦF = 0.01) due to aggregation.

Molbank doi: 10.3390/M2121

Authors: Elizaveta I. Samorodova Anastasia R. Kovrizhina Andrei I. Khlebnikov

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.

Molbank doi: 10.3390/M2120

Authors: Haoni Wang Meiting Zhang Jianwei Wu Junqi Zhang Xianglong Meng Yuliang Yang

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.

Molbank doi: 10.3390/M2119

Authors: Diana Becerra Diana Hurtado-Rodríguez Juan-Carlos Castillo

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.

Molbank doi: 10.3390/M2118

Authors: Anna A. Moroz Maksim V. Dmitriev Andrey N. Maslivets

The 1,4-dipolar cycloaddition of the ylidene derivative of 1H-pyrrole-2,3-dione to a dipole generated in situ from 1-benzylbenzimidazole and dimethyl acetylenedicarboxylate proceeds via the exocyclic multiple bond of the ylidene derivative and affords a mixture of diastereomeric spiro[benzo[4,5]imidazo[1,2-a]pyridine-3,3’-pyrroles], which slowly epimerized in a solution.

Molbank doi: 10.3390/M2117

Authors: Werner Seebacher Antoine Dupé Eva-Maria Pferschy-Wenzig Robert Saf Theresa Hermann Robert Weis

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.

Molbank doi: 10.3390/M2116

Authors: Dzhamilia N. Belozerova Maksim V. Dmitriev Irina V. Mashevskaya

A novel spiro-pyrrolothiazole derivative bearing a 2-oxindole substituent was synthesized and characterized. The compound was prepared via a catalyst-free reaction under mild conditions and isolated using a straightforward workup procedure. The structure of the synthesized title compound was confirmed with 1H, 13C NMR spectra and X-Ray diffraction data.