2878-50-4

Upstream product

• 123-08-0 4-hydroxy-benzaldehyde 
• 100-65-2 N-Phenylhydroxylamine 
• 1689-73-2 N-(p-hydroxybenzylidene)aniline 
• 98-95-3 nitrobenzene 
• 62-53-3 aniline 

Downstream Products

• 52881-07-9 4-(4,4-dioxo-2-phenyl-3,3a,4,8b-tetrahydro-2H-4λ⁶-benzo[4,5]thieno[2,3-d]isoxazol-3-yl)-phenol 
• 123-08-0 4-hydroxy-benzaldehyde 
• 586-96-9 Nitrosobenzene 
• 17474-27-0 5-(4-hydroxy-benzylidene)-2,2-dimethyl-[1,3]dioxane-4,6-dione 
• 37797-12-9 9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione 
• 329736-70-1 (4-hydroxybenzylidene)bis(dimedone) 
• 1209004-38-5 (E)-ethyl 3-((4-hydroxyphenyl)(phenyl)amino)acrylate 

Relevant academic research and scientific papers

N-(p-hydroxybenzylidene)phenylamine N-oxide

The crystal structure of the title compound, C13H11NO2, confirms that it exists as a nitrone. The geometry about C double bond N is Z. The torsion angles O8-N8-C7-H7 [174.55 (2)°] and C8-N8-C7-H7 [-0.89 (4)°] indicate the

Optimized aqueous Kinugasa reactions for bioorthogonal chemistry applications

Kinugasa reactions hold potential for bioorthogonal chemistry in that the reagents can be biocompatible. Unlike other bioorthogonal reaction products, β-lactams are potentially reactive, which can be useful for synthesizing new biomaterials. A limiting factor for applications consists of slow reaction rates. Herein, we report an optimized aqueous copper(i)-catalyzed alkyne-nitrone cycloaddition involving rearrangement (CuANCR) with rate accelerations made possible by the use of surfactant micelles. We have investigated the factors that accelerate the aqueous CuANCR reaction and demonstrate enhanced modification of a model membrane-associated peptide. We discovered that lipids/surfactants and alkyne structure have a significant impact on the reaction rate, with biological lipids and electron-poor alkynes showing greater reactivity. These new findings have implications for the use of CuANCR for modifying integral membrane proteins as well as live cell labelling and other bioorthogonal applications.

Synthesis and Antimicrobial Evaluation of New Pyrrolo-isoxazolidine Derivatives

In the present study, pyrrolo-isoxazolidines 3(a-l) and 4(a-e), 4g, 4i, 4j have been synthesized by using the 1,3-dipolar cycloaddition reactions of nitrones 1(a-l) with ester substituted N-aryl maleimide (2b). These heterocycles have been obtained in cis and trans diastereomeric forms. The structures of newly synthesized heterocycles have been confirmed from their spectroscopic parameters such as IR,1H NMR,13C NMR and ESI-MS. The in vitro antimicrobial evaluation of these compounds were also investigated. Most of the prepared heterocycles showed significant antimicrobial properties. C3-phenyl substituted products exhibited the remarkable antibacterial behaviours while C3-thienyl/furyl substituted heterocycles proved themselves potent antifungal agents.

Direct oxidative synthesis of nitrones from aldehydes and primary anilines using graphite oxide and Oxone

One-pot condensation/oxidation of aldehydes and primary anilines into nitrones using graphite oxide (GO) and Oxone as the oxidant under very mild reaction conditions is described. The proposed method provides a direct oxidative synthesis of various nitrones in good to excellent yields under metal-free conditions in short reaction times.

Synthesis and evaluation of novel 4-[(3H,3aH,6aH)-3-phenyl)-4,6-dioxo-2- phenyldihydro-2H-pyrrolo[3,4-d]isoxazol-5(3H,6H,6aH)-yl]benzoic acid derivatives as potent acetylcholinesterase inhibitors and anti-amnestic agents

The present study was designed to synthesize and evaluate pyrrolo-isoxazole benzoic acid derivatives as potential acetylcholinesterase (AChE) inhibitors for the management of Alzheimer's disease. The synthesis of pyrrolo-isoxazole benzoic acid derivatives involved ring opening cyclization of p-aminobenzoic acid with maleic anhydride to yield maleanilic acid, which in turn afforded N-arylmaleimide via ring closed cyclization. Azomethine-N-oxides were obtained by condensation of N-arylhydroxylamine with differently substituted benzaldehydes followed by refluxing of N-arylmaleimide with differently substituted azomethine-N-oxides to pyrrolo-isoxazole benzoic acid derivatives as cis- and trans-stereoisomers. The synthesized compounds were evaluated in vitro for AChE inhibitory activity in rat brain homogenate with donepezil as standard AChE inhibitor. Thereafter, the most potent test compound was evaluated for in vitro butyrylcholinesterase inhibitory activity and in vivo memory evaluation in scopolamine (0.4 mg/kg)-induced amnesia in mice by employing Morris water maze test. All pyrrolo-isoxazole benzoic acid derivatives demonstrated potent AChE inhibitory activity. Most of compounds exhibited similar activity to donepezil and four of them (7h, 7i, 8i, and 8h, IC50 = 19.1 ± 1.9-17.5 ± 1.5 nM) displayed higher inhibitory activity as compared to donepezil (21.5 ± 3.2 nM) with compound 8ia (IC50 = 17.5 ± 1.5 nM) being the most active one. The test compound 8ia also ameliorated scopolamine-induced amnesia in mice in terms of restoration of time spent in target quadrant (TSTQ) and escape latency time (ELT). It may be concluded that pyrrolo-isoxazole benzoic acid derivatives may be employed as potential AChE inhibitors.

Synthesis and evaluation of hexahydropyrrolo[3,4-d]isoxazole-4,6-diones as anti-stress agents

A series of 2,3-diphenyl-5-(naphthalen-1-yl)-4H-2,3,3a,5,6,6a- hexahydropyrrolo[3,4-d]isoxazole-4,6-dione derivatives were synthesized via 1,3-dipolar cycloaddition of azomethine N-oxides with N-(α-naphthyl) maleimide. The pyrrolo-isoxazole derivatives were assigned cis- and trans- configurations (3-A and 3-B) with respect to proton C3-H on azomethinic carbon on the basis of their 1H NMR. The reaction proceeds through cis- endo addition rule indicating the predominance of cis isomer. The cis- and trans- isomers of a prototype compound 3a i.e., compound 3a-A and compound 3a-B were evaluated for anti-stress activity in immobilization-induced acute stress. Compound 3a-A (5 and 10 mg/kg) and compound 3a-B (10 mg/kg) attenuated immobilization stress-induced behavioral alterations in Swiss albino mice suggesting that pyrrolo-isoxazole may serve as lead molecule for the development of anti-stress agents.

Synthesis and bioorthogonal coupling chemistry of a novel cyclopentenone-containing unnatural tyrosine analogue

Herein we report the synthesis of a novel amino acid with orthogonal functionality to the natural amino acid side chains. Tyrosine was O-alkylated with a cyclic 5-membered α,β-unsaturated ketone ring (5). We have established that this amino acid analogue can undergo cycloaddition reactions in aqueous media with in situ generated nitrones. Nitrone formation occurred by micellar catalysis can undergo aqueous 1,3-dipolar cycloaddition reactions with the unnatural Tyr. We also performed a linear free energy analysis of the one pot bioconjugation reaction in water using cyclopentenone as a model for the Tyr analogue and seven different aryl nitrones. We found that the Hammett ρ value was -0.94, suggesting that the reaction occurs in a concerted fashion with a slight positive charge buildup in the transition state. The Hammett ρ value also suggests that the bioconjugation reaction is tolerant of different substituents and thus may be useful for introducing novel functionality into peptides and proteins containing the Tyr analogue 5. The aqueous 1,3-dipolar cycloaddition reactions, that use nitrones to trap the O-alkylated Tyr 5, establish a novel strategy for rapid, water compatible bioconjugation reactions.