2-nitrobenzenesulfonyl Chloride Research Articles

Characterization of Tridax procumbens amines with a potential to synthesize silver nanoparticles

Our previous findings showed that amines from Tridax procumbens (Family: Asteraceae) were responsible for the synthesis of silver nanoparticles. T. procumbens is a weed plant with rich source of medicinal compounds. In the current work, we studied the initial characterization of bioactive compounds by LC-MS, an essential tool for the characterization and identification of low molecular compounds. Further the isolated compounds were investigated for silver nanoparticle synthesis. The leaf extracts examined revealed many novel amine derivative compounds reported for the first time mainly belonging to the group of free amines: n-Pentylhydrazine hydrochloride, 2-Nitrobenzenesulfonyl chloride, 1,7-Dichlorooctamethyltetrasiloxane, 5-Chloro-1,2,4-trihydroxybenzene, 3-Chloro-2-hydroxy-5-(trifluoromethyl)pyridine and 2-(Diphenylphosphino) ethyltriethoxysilane and conjugated amines: 5-Methoxy-diisopropyltryptamine, 4-Chlorophenoxyacetic acid, Diphenhydramine, Erucamide, n(4-((2-(2,5-dimethoxybenzylidene)hydrazino)carbonyl)ph)-4-me-benzenesulfonamide and 1,3,5-Trithia-2,4,6-tristannacyclohexane, 2,2,4,4,6,6-hexamethyl. Characterization by UV-Vis spectra, XRD, EDX and TEM revealed well separated spherical shaped AgNPs size ranging 8-50 nm. These findings suggest that further work could be extended to isolate and elucidate the structures of the identified molecules using powerful instruments such as HPLC-MS, HPLC-NMR and high resolution-MS (HR-MS). Further biotechnological approaches towards synthesis of novel metals will be enhanced to promote green chemistry technology for the synthesis of nanoparticles.

Synthesis of Polysubstituted Pyridines and Pyrazines via Truce-Smiles Rearrangement of Amino Acid-Based 4-Nitrobenzenesulfonamides.

Immobilized l-glutamic acid β-methyl ester was sulfonylated with 4-nitrobenzenesulfonyl chloride and alkylated with various α-haloketones. The resulting sulfonamides were reacted with potassium trimethylsilanolate. Then, upon cleavage from the polymer support, tetrasubstituted pyridines were produced as the result of one-step C-arylation, aldol condensation, and oxidation. When cleavage from the resin occurred before the trimethylsilanolate treatment, C-arylation was followed by enamination, which yielded trisubstituted pyrazines. Through the developed protocols, targeted synthesis of novel heterocyclic derivatives was performed using mild reaction conditions and a number of readily available starting materials.

Reactions of two primary aromatic amines in modified supercritical carbon dioxide to synthesize sulfonamides: On-line SFC to perform solubility measurements and method to monitor reaction progress

Aniline and phenylethylamine react with 4-nitrobenzenesulfonyl chloride in 4% acetone modified supercritical fluid carbon dioxide (SFCO2) to produce nitro-sulfonamide products via NS bond formation. Solubility measurements of reactants and products in pure SFCO2 were performed at temperatures 353 K, 363 K, 373 K with pressures ranging from 10 MPa to 20.3 MPa. Aniline exhibits good solubility in SFCO2 and unlike phenylethylamine does not form a carbamate. Estimates of free phenylethylamine release efficiency from its pre-formed carbamate in SFCO2 were obtained. Synthetic reactions were performed at 16.8 MPa with temperatures 353 K, 363 K, and 373 K. Under such conditions, on-line SFC reaction progress monitoring established phenylethylamine effectively reacted as a free base at approximately four times the rate of aniline. Nitro-sulfonamide product yields were 75–82.6% using phenylethylamine and 53.9–70.2% using aniline. Aniline product yields were lower due to by-product formation. This study involved using two different interchangeable on-line SFC interfaces.

Determination of Quisqualic Acid in quisqualis fructus by Pre-column Derivatization and High Performance Liquid Chromatography

A convenient, cheap and accurate method for the determination of quisqualic acid in traditional Chinese medicine Quisqualis fructus by pre-column derivatization with 2-nitrobenzenesulfonyl chloride and HPLC was established. Quisqualis fructus samples were homogenised in water after being crushed and degreased with petroleum ether. Target compounds were separated and detected on a C18 column using gradient elution. The recovery rates were in the range of 90–103%. Good linearity within the range of 0.2–20 mg/mL for quisqualic acid with correlation coefficients of ≥0.98 was observed. The relative standard deviations (RSDs) of the within-day and between-day retention time precisions were 0.15–0.17% and 0.8–0.9%, respectively. The RSDs of the within-day and between-day integrated area precisions were 2.3–6.4% and 4.8–9.8%, respectively. The concentrations of quisqualic acid (1.5 mg/g) from Quisqualis fructus were conveniently measured without any expensive photodiode array detector but with a common UV–visible detector.

Synthesis, crystal structure and docking studies of tetracyclic 10-iodo-1,2-dihydroisoquinolino[2,1-b][1,2,4]benzothiadiazine 12,12-dioxide and its precursors.

The title compound, 10-iodo-1,2-dihydroisoquinolino[2,1-b][1,2,4]benzothiadiazine 12,12-dioxide, C15H11IN2O2S (8), was synthesized via the metal-free intramolecular N-iodosuccinimide (NIS)-mediated radical oxidative sp3-C-H aminative cyclization of 2-(2'-aminobenzenesulfonyl)-1,3,4-trihydroisoquinoline, C15H16N2O2S (7). The amino adduct 7 was prepared via a two-step reaction, starting from the condensation of 2-nitrobenzenesulfonyl chloride (4) with 1,2,3,4-tetrahydroisoquinoline (5), to afford 2-(2'-nitrobenzenesulfonyl)-1,3,4-trihydroisoquinoline, C15H14N2O4S (6), in 82% yield. The catalytic hydrogenation of 6 with hydrogen gas, in the presence of 10% palladium-on-charcoal catalyst, furnished 7. Products 6-8 were characterized by their melting points, IR and NMR (1H and 13C) spectroscopy, and single-crystal X-ray diffraction. The three compounds crystallized in the monoclinic space group, with 7 exhibiting classical intramolecular hydrogen bonds of 2.16 and 2.26 Å. All three crystal structures exhibit centrosymmetric pairs of intermolecular C-H...π(ring) and/or π-π stacking interactions. The docking studies of molecules 6, 7 and 8 with deoxyribonucleic acid (PDB id: 1ZEW) revealed minor-groove binding behaviours without intercalation, with 7 presenting the most favourable global energy of the three molecules. Nonetheless, molecule 8 interacted strongly with the DNA macromolecule, with an attractive van der Waals energy of -15.53 kcal mol-1.

High boron removal polyamide reverse osmosis membranes by swelling induced embedding of a sulfonyl molecular plug

The removal of small and neutral boron molecules from seawater remains a critical challenge in energy-saving and low-cost desalination. In this paper, a high boron removal reverse osmosis (RO) membrane was designed by embedding sulfonyl moleculars in the polyamide (PA) network. The swelling PA structure has enlarged free volumes. It would induce more facile penetration of 4-nitrobenzenesulfonyl chloride (NBS). Evaporation of solvent molecules contracts the PA network and leads to the fixation of the NBS molecules into the PA network. The swelling of the polyamide network was studied systematically. The most suitable swelling solvent was selected based on the solubility parameter and the restoration capability. The “swelling-embedding-shrinking (SES)” strategy reconstruct the free volume of PA chains. It resulted in significantly higher rejection of neutral boron molecules due to enhanced steric hindrance by embedded NBS plugs and synergistic exclusion effect by –SO3H groups. Meanwhile, the alteration of membrane composition and structure were kept minimal. Further, the impacts of key determining factors (polarity, steric hindrance, and affinity) on boron separation performance were systematically analyzed by boron-containing compounds with different numbers of hydrogen bonding sites (or dipole moments) or molecular volumes. Under simulated seawater conditions, the boron rejection of the SES modified reverse osmosis membranes increased from 82.12% to 93.10%, and the salt rejection rate increased to 99.57%. Our study shows that the swelling induced embedding of NBS molecules can be readily adopted to regulate the permselectivity of the PA layer towards removal of boron species.

Polymer-Assisted Synthesis of Single and Fused Diketomorpholines.

The synthesis of different diketomorpholines via N-acyl-3,4-dihydro-2 H-1,4-oxazine-3-carboxylic acids is reported in this article. The key intermediates were prepared using a convenient solid-phase synthesis starting from polymer-supported Ser( tBu)-OH. After subsequent sulfonylation with 4-nitrobenzenesulfonyl chloride (4-Nos-Cl), alkylation with an α-bromoketone, cleavage of the 4-Nos group and acylation with an α-halocarboxylic acids, acid-mediated cleavage from the resin yielded dihydrooxazine-3-carboxylic acids in high crude purities. Depending on the reaction conditions, exposure to base resulted in cyclization to either oxazino[3,4- c][1,4]oxazine-diones or 3-methylidenemorpholine-2,5-diones. Further reaction with triethylsilane-trifluoroacetic acid (TES/TFA) led to olefin reduction, in the case of oxazino[3,4- c][1,4]oxazine-dione with full control of the newly formed stereocenter.

Synthesis of 2-Alkylsulfonyl-imidazoles with Three Diversity Positions from Immobilized α-Acylamino Ketones.

The synthesis of novel imidazole derivatives via immobilized α-acylamino ketones is reported in this article. The key intermediates were prepared from the Wang-piperazine resin-supported Fmoc-amino acids. After their sulfonylation with 4-nitrobenzenesulfonyl chloride (4-Nos-Cl), followed by alkylation with α-bromoketones and cleavage of Nos group, the resulting α-acylamino ketones were reacted with Fmoc-isothiocyanate. The corresponding Fmoc-thioureas were subjected to the Fmoc-cleavage and spontaneous ring-closure to imidazole scaffold. The resulting imidazole-thiones were alkylated with alkyl halides and oxidized using meta-chloroperbenzoic acid ( mCPBA). Trifluoroacetic acid (TFA)-mediated cleavage yielded the corresponding trisubstituted 2-alkylsulfonyl imidazoles in good crude purity and acceptable overall yields. In the case of sulfides, prepared from alkyl bromides, the unexpected products brominated at the C4 position of the imidazole were obtained.

Convenient Synthesis of Thiohydantoins, Imidazole-2-thiones and Imidazo[2,1-b]thiazol-4-iums from Polymer-Supported α-Acylamino Ketones.

The preparation of 5-methylene-thiohydantoins using solid-phase synthesis is reported in this paper. After sulfonylation of immobilized Ser (t-Bu)-OH with 4-nitrobenzenesulfonyl chloride followed by alkylation with various bromoketones, the 4-Nos group was removed and the resulting polymer-supported α-acylamino ketones reacted with Fmoc-isothiocyanate. Cleavage of the Fmoc protecting group was followed by the spontaneous cyclative cleavage releasing the 5-methylene-thiohydantoin derivatives from the polymer support. Reduction with triethylsilane (TES) yielded the corresponding 5-methyl-thiohydantoins. When Fmoc-isothiocyanate was replaced with alkyl isothiocyanates, the trifluoroacetic acid (TFA) mediated cleavage from the polymer support, which was followed by the cyclization reaction and the imidazo[2,1-b]thiazol-4-iums were obtained. Their conversion in deuterated dimethylsulfoxide led to imidazole-2-thiones.

Polymer-Supported Stereoselective Synthesis of Benzoxazino[4,3-b][1,2,5]thiadiazepinone 6,6-dioxides.

Herein, we report the stereoselective synthesis of trisubstituted benzoxazino[4,3-b][1,2,5]thiadiazepinone 6,6-dioxides from polymer-supported Fmoc-Ser(tBu)-OH and Fmoc-Thr(tBu)-OH. After the solid-phase synthesis of N-alkylated-N-sulfonylated intermediates using various 2-nitrobenzenesulfonyl chlorides and bromoketones, the target compounds were obtained via trifluoroacetic acid (TFA)-mediated cleavage from the resin, followed by cyclization of the diazepinone scaffold. Except for the threonine-based intermediates, the inclusion of triethylsilane (TES) in the cleavage cocktail yielded a specific configuration of the newly formed C3 chiral center. The final cyclization resulted in minor or no inversion of the C12a stereocenter configuration.

Solid-Phase Synthesis of 2,3-Dihydrobenzo[f][1,2,5]thiadiazepin-4(5H)-one 1,1-Dioxides with Three Diversity Positions.

Synthesis of 2,3-dihydrobenzo[f][1,2,5]thiadiazepin-4(5H)-one 1,1-dioxides from polymer-supported α-amino acids is described herein. Different α-amino acids immobilized on Wang resin were sulfonylated with various 2-nitrobenzenesulfonyl chlorides. The resulting 2-nitrobenzenesulfonamides were alkylated with alcohols according to the Fukuyama-Mitsunobu procedure. After reduction of the nitro group and cleavage from the polymer support, the final intermediates were reacted with thionyl chloride, and target compounds of good crude purity and acceptable overall yields were obtained. The chiral HPLC studies revealed the impact of the cyclization step on the resulting stereochemistry. The developed strategy allows for simple production of desired compounds with the application of parallel/combinatorial solid-phase synthesis using commercially available building blocks.

Synthesis and Characterization of Poly[N-(4-nitrobenzenesulfonyl)-2-ethynylpyridinium chloride

An ionic polyacetylene with 4-nitrobenzenesulfonyl substituents was easily prepared via the non-catalyst polymerization of 2-ethynylpyridine using 4-nitrobenzenesulfonyl chloride. The polymerization proceeded in homogeneous manner to give a moderate yield of polymer (65 %). The polymer structure was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed N-(4-nitrobenzenesulfonyl)pyridinium chloride. The photoluminescence peak was observed at 584 nm corresponding to a photon energy of 2.12 eV although it is weak due to nitro group. Based on absorption spectrum, band gap was 2.16 eV. The cyclic voltammograms of polymer exhibited the electrochemically stable window at the −1.8 ∼ 1.50 V region. Oxidation and reduction were started at 0.43 and −0.9 V and had stable electrochemical property up to 30 cycles.

Ring contraction of 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides: access to 4H-benzo[b][1,4]thiazine 1,1-dioxides.

We report an efficient synthesis of 4H-benzo[b][1,4]thiazine 1,1-dioxides via unprecedented ring contraction of 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides under mild conditions involving carbon-sulfur bond formation. 2,5-Dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides are easily accessible from commercially available building blocks, including Fmoc-protected amino acids, 2-nitrobenzenesulfonyl chlorides, and bromo ketones. Benzothiazine 1,1-dioxides represent pharmacologically relevant derivatives with biological, medicinal, and industrial applications.

Solid-phase synthesis of 2-aryl-3-alkylamino-1H-indoles from 2-nitro-N-(2-oxo-2-arylethyl)benzenesulfonamides via base-mediated C-arylation.

Polymer-supported 2-nitro-N-(2-oxo-2-arylethyl)benzenesulfonamides, prepared from resin-bound amines by sulfonylation with 2-nitrobenzenesulfonyl chlorides followed by alkylation with α-bromoacetophenones, represent advanced intermediates for the synthesis of different nitrogenous heterocycles. We report their application for the synthesis of 2-aryl-3-alkylamino-1H-indoles via base-mediated C-arylation reactions followed by the reduction of the C-arylated intermediates. Linear precursors for C-arylation were prepared on solid-phase support from simple, commercially available building blocks. The effects of different substituents on the amino and aryl groups were addressed.

A reaction based chromofluorogenic turn-on probe for specific detection of fluoride over sulfide/thiols

A new reaction based probe fluorescein nosylate (R1) has been designed and synthesized for selective recognition of F− in acetonitrile (CH3CN) by exploiting both its nucleophilic and basic character. Probe R1 consists of fluorescein dye as a signalling unit while 4-nitrobenzenesulfonyl chloride as the masking unit. The F− plays the role of de-masking agent to set free the fluorescein moiety in its open form from R1 leading to significant changes in its absorption/emission profile. The detection of F− amidst of sulfide/thiols through receptors undergoing nucleophilic scission is a tedious job due to similarity in their extent of basicity/nucleophilicity. Here, we present a convenient solution for the same in the form of R1 which detects F− selectively over sulfide/thiols in CH3CN with a high detection limit of 4.6×10−7M and 2.75×10−8M determined through UV–visible and fluorescence titration data, respectively.

Solid-phase synthesis of trisubstituted 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxide derivatives.

The solid-phase synthesis of trisubstituted 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides is reported. Acyclic polymer-supported intermediates were prepared using commercially available building blocks: Fmoc-protected amino acids, 2-nitrobenzenesulfonyl chlorides, and bromoketones. The acyclic precursors underwent acid-mediated release from the resin and the cyclization was completed in solution.

Solid-phase synthesis of anagrelide sulfonyl analogues.

Simple solid-phase synthesis of 3,10-dihydro-2H-benzo[e]imidazo[1,2-b][1,2,4]thiadiazin-2-one 5,5-dioxides is described, with Fmoc-α-amino acids and 2-nitrobenzenesulfonyl chlorides (2-NosCls) being the key building blocks. Fmoc-α-amino acids were immobilized on Wang resin and transformed to the corresponding 2-nitrobenzenesulfonamides in two steps. After reduction of the nitro group, Fmoc-thioureas were synthesized followed by cyclization of the 1,2,4-benzothiadiazine-1,1-dioxide scaffold with diisopropylcarbodiimide (DIC). Cleavage of the Fmoc protecting group followed by spontaneous cyclative cleavage gave the target products in excellent crude purity.

Synthetic and mechanistic insight into nosylation of glycine residues

The Fukuyama-Mitsunobu alkylation procedure is widely used to introduce alkyl substituents to amino groups in general and N-alkylation of peptides in particular. Here we have investigated the procedure in detail for N-alkylation of peptides with N-terminal glycine residues, based on the observation that standard conditions lead to substantial bis-nosylation of the glycine amino group. A systematic evaluation of this observation was carried out and it was demonstrated that for peptides with alanine, β-alanine or γ-aminobutyric acid (GABA) as N-terminal residues mono-nosylation was observed under the same conditions. Moreover, bis-nosylation was independent of the type of resin, neighboring amino acid and nature of the peptide. Calculations suggest that the reason for the bis-nosylation is the fact that the deprotonated mono-nosyl species is particularly stable in the case of the terminal Gly residue because the N(-) residue can become closer to the SO(2) unit. Finally, the mono-nosylated N-terminal glycine could be obtained by careful optimization of the procedure, adding only one equivalent of 2-nitrobenzenesulfonyl chloride.

Gas electron diffraction and quantum chemical study of the structure of a 2-nitrobenzenesulfonyl chloride molecule

A combined gas electron diffraction and quantum chemical (B3LYP/6-311+G**, B3LYP/cc-pVTZ, B3LYP/cc-pVTZ, midix (Cl), and MP2/cc-pVTZ) study of the structure of a 2-NO2-C6H4-SO2Cl molecule is performed. It is found experimentally that at a temperature of 345(5) K the gas phase contains two conformers of the C1 symmetry. Conformer I with a nearly perpendicular arrangement of the S-Cl bond with respect to the benzene ring plane (the C(NO2)-C-S-Cl torsion angle is 84(3)°) is contained predominantly (69(12)%). In conformer II, the S-Cl bond is located near the benzene ring plane (the C(NO2)-C-S-Cl angle is 172(3)°). The following experimental internuclear distances (A) are obtained for conformer I: rh1(C-H) = 1.064(15), rh1(C-C)av = 1.397(3), rh1(C-S) = 1.761(6), rh1(S-O)av = 1.426(4), rh1(S-Cl) = 2.043(5), rh1(N-O)av = 1.222(4), rh1(C-N) = 1.485(16). In both conformers, the NO2 group is turned by more than 30° relative to the benzene ring plane.

Synthesis of Quinazolines from N-(2-Nitrophenylsulfonyl)iminodiacetate and α-(2-Nitrophenylsulfonyl)amino Ketones via 2H-Indazole 1-Oxides

Base-catalyzed rearrangement of 2H-indazoles 1-oxides, prepared by tandem carbon-carbon followed by nitrogen-nitrogen bond formations from easily accessible N-alkyl-2-nitro-N-(2-oxo-2-aryl-ethyl)-benzenesulfonamides using glycine, 2-nitrobenzenesulfonyl chlorides, and bromo ketones/acetates, yielded high purity quinazolines.