A novel one-pot synthesis of isomeric naphtho[1,2-d]isoxazole 2-oxide and naphtho[1,8-de][1,2]oxazine ring systems. A case of simultaneous o- and peri-cyclisation in naphthalene

Supsana, Paraskevi; Tsoungas, Petros G.; Varvounis, George

doi:10.1016/s0040-4039(00)00029-0

Cited by 22 publications

(13 citation statements)

References 15 publications

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“…While the oxime ethers, unlike the hydrazones, appear stable toward Schiff base hydrolysis in neutral and basic conditions, they can still slowly decompose with first-order kinetics apparently by cleavage of their N−O bond to afford a phenol and an arylnitrile. This N−O bond cleavage, while precedented at higher temperatures, was not expected under such mild conditions. − …”

Section: Resultsmentioning

confidence: 84%

“…This N-O bond cleavage, while precedented at higher temperatures, was not expected under such mild conditions. [60][61][62][63][64][65][66][67] The oxime ethers are qualitatively more stable than the analogous hydrazones according to their apparent degradation "half-lives" (apparent hydrazone "half-lives" refer to the time required for 50% disappearance, as the degradation process is not first-order). Electron-donating groups and ortho-substituents on either aromatic ring appear to increase the degradation rate of both the bisarylaldoxime ethers and bisarylhydrazones.…”

Section: Introductionmentioning

confidence: 99%

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Bisaryloxime Ethers as Potent Inhibitors of Transthyretin Amyloid Fibril Formation

et al. 2005

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Amyloid fibril formation by the plasma protein transthyretin (TTR), requiring rate-limiting tetramer dissociation and monomer misfolding, is implicated in several human diseases. Amyloidogenesis can be inhibited through native state stabilization, mediated by small molecule binding to TTR's primarily unoccupied thyroid hormone binding sites. New native state stabilizers have been discovered herein by the facile condensation of arylaldehydes with aryloxyamines affording a bisarylaldoxime ether library. Of the library's 95 compounds, 31 were active inhibitors of TTR amyloid formation in vitro. The bisaryloxime ethers selectively stabilize the native tetrameric state of TTR over the dissociative transition state under amyloidogenic conditions, leading to an increase in the dissociation activation barrier. Several bisaryloxime ethers bind selectively to TTR in human blood plasma over the plethora of other plasma proteins, a necessary attribute for efficacy in vivo. While bisarylaldoxime ethers are susceptible to degradation by N-O bond cleavage, this process is slowed by their binding to TTR. Furthermore, the degradation rate of many of the bisarylaldoxime ethers is slow relative to the half-life of plasma TTR. The bisaryloxime ether library provides valuable structure-activity relationship insight for the development of structurally analogous inhibitors with superior stability profiles, should that prove necessary.

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Section: Resultsmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Bisaryloxime Ethers as Potent Inhibitors of Transthyretin Amyloid Fibril Formation

et al. 2005

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“…Compound (12) was excluded on the grounds that it did not fit with any of the spectral data (see Supplementary Materials for the mentioned spectra). Isomeric compound 10 was also excluded from being the product because of possible inherent structural instability, because the analogous naphtho[1,2-d]isoxazole 2-oxide (9) was synthesized only once [15] and thereafter proved to be unstable [16].…”

Section: Discussionmentioning

confidence: 99%

3-Phenyl-3H-naphtho[1,2-e][1,2,3]oxadiazine

Aouant

Varvounis

2022

Molbank

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In this study, we considered the reaction of (E)-1-[(2-phenylhydrazono)methyl]naphthalen-2-ol with iodobenzene diacetate in dichloromethane-produced novel 3-phenyl-3H-naphtho[1,2-e][1,2,3]oxadiazine in 11% yield. By analogy to previously published work, we suggested that the reaction proceeds via the intermediacy of an o-naphthoquinone azomethide that undergoes conjugated 6π-electrocylization to produce the product. 1D, 2D NMR, HRMS, IR, and UV-VIS spectra provided information that supported the structure of the product.

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“…Oxazine with naphthalene rings, called naphthoxazines have different pharmacological activities such as antiparkinson, psycho stimulating, anti-tumor, and antidepressant [ 10 ]. Besides, this structure can be used as potent forerunners in organic synthesis to found novel biologically active molecules [ 13 ]. Hence, these compounds are an interesting category of chemical for researchers, and there is enough scope to explore new oxazine derivatives.…”

Section: Introductionmentioning

confidence: 99%

Efficient synthesis of 1,3-naphtoxazine derivatives using reusable magnetic catalyst (GO-Fe3O4–Ti(IV)): anticonvulsant evaluation and computational studies

et al. 2022

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A series of 2-aryl/alkyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines (S1–S11) were synthesized with an eco-friendly and recoverable nanocatalyst (GO-Fe3O4–Ti(IV)) as an efficient magnetic composite. The new nanocatalyst was characterized by FT-IR, XRD and, EDS analysis. A conformable procedure, easy to work up and having a short reaction time with high yields are some advantages of this method. The new catalyst is also thermal-stable, reusable and, environment-friendly. The chemical structures of the synthesized 1,3-oxazine compounds were confirmed by comparing their melting points with those reported in literature. Then, the anticonvulsant activity of these compounds was assessed by the intraperitoneal pentylenetetrazole test (ipPTZ). Compounds S10 and S11 displayed considerable activity against chemically-induced seizure tests. The molecular simulation was also done to achieve their binding affinities as γ‐aminobutyric acid A (GABA‐A) receptor agonists as an assumptive mechanism of their anticonvulsant action. The result of molecular studies represented strongly matched with biological activity. Molecular docking simulation of the potent compound (S10) and diazepam as the positive control was performed and some critical residues like Thr262, Asn265, Met286, Phe289, and Val290 were identified. Based on the anticonvulsant results and also in silico ADME predictions, S11 can be to become a potential drug candidate as an anticonvulsant agent.

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A novel one-pot synthesis of isomeric naphtho[1,2-d]isoxazole 2-oxide and naphtho[1,8-de][1,2]oxazine ring systems. A case of simultaneous o- and peri-cyclisation in naphthalene

Cited by 22 publications

References 15 publications

Bisaryloxime Ethers as Potent Inhibitors of Transthyretin Amyloid Fibril Formation

Bisaryloxime Ethers as Potent Inhibitors of Transthyretin Amyloid Fibril Formation

3-Phenyl-3H-naphtho[1,2-e][1,2,3]oxadiazine

Efficient synthesis of 1,3-naphtoxazine derivatives using reusable magnetic catalyst (GO-Fe3O4–Ti(IV)): anticonvulsant evaluation and computational studies

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