174769-28-9

Upstream product

• 824-46-4 methoxyhydroquinone 
• 121-33-5 vanillin 

Downstream Products

• 23030-65-1 2-bromo-5-methoxycyclohexa-2,5-diene-1,4-dione 
• 387401-03-8 1-bromo-4-methoxy-2,5-bis-triethylsilanyloxy-benzene 
• 1402158-27-3 9-benzyloxy-2,7-dihydroxy-3-methoxy-6H-benzo[c]chromen-6-one 
• 42719-66-4 altenuisol 
• 923025-92-7 1-bromo-4-methoxy-2,5-bis(methoxymethoxy)benzene 
• 387401-20-9 2-Methoxy-5-((E)-5-methyl-4-oxo-hex-1-enyl)-[1,4]benzoquinone 

Relevant academic research and scientific papers

Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

2,3-Dichloropyridine N-oxide, a novel oxygen transfer reagent, allows the conductance of the gold(I)-catalyzed oxidation of alkynes to 1,2-dicarbonyls in the absence of any acid additives and under mild conditions to furnish the target species, including those derivatized by highly acid-sensitive groups. The developed strategy is effective for a wide range of alkyne substrates such as terminal- and internal alkynes, ynamides, alkynyl ethers/thioethers, and even unsubstituted acetylene (40 examples; yields up to 99%). The oxidation was successfully integrated into the trapping of reactive dicarbonyls by one-pot heterocyclization and into the synthesis of six-membered azaheterocycles. This synthetic acid-free route was also successfully applied for the total synthesis of a natural 1,2-diketone.

Quinoides and VEGFR2 TKIs influence the fate of hepatocellular carcinoma and its cancer stem cells

Bioactivities of quinoides 1-5 and VEGFR2 TKIs 6-10 in hepatocellular cancer (HCC) and cancer stem cells (HCSCs) were studied. The compounds exhibited IC50 values in μM concentrations in HCC cells. Quinoide 3 was able to eradicate cancer stem cells, similar to the action of the stem cell inhibitor DAPT. However, the more cytotoxic VEFGR TKIs (IC50: 0.4-3.0 μM) including sorafenib, which is the only FDA approved drug for the treatment of HCC, enriched the hepatocellular cancer stem cell population by 2-3 fold after treatment. An aggressiveness factor (AF) was proposed to quantify the characteristics of drug candidates for their ability to eradicate the CSC subpopulation. Considering the tumour heterogeneity and marker positive cancer stem cell like subpopulation enrichment upon treatments in patients, this study emphasises the importance of the chemotherapeutic agent choice acting differentially on all the subpopulations including marker-positive CSCs.

Revision of the structure and total synthesis of altenuisol

A total synthesis of the reported structure of altenuisol is described. Comparison of the 1H NMR spectra of the synthesized compound and of the natural product revealed that the originally proposed structure was not correct. Consequently, two constitutional isomers were synthesized. The spectra of one of these compounds - a structure originally proposed as the structure of altertenuol - matched perfectly with the spectra of the natural product. The total synthesis of altenuisol was thus achieved starting with phloroglucinic acid and protocatechuic aldehyde in 10 steps and in 23% yield, where the longest linear sequence consisted of 6 steps. The key step was a Suzuki coupling with concomitant formation of the lactone ring. Whether altertenuol is identical with altenuisol could not be decided. Total synthesis of altenuisol, a minor toxin in ubiquitous Alternaria spp. revealed that the originally proposed structure was not correct. Altenuisol was proved to have an isomeric structure by total synthesis. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total synthesis of graphislactones A, C, D, and H, of ulocladol, and of the originally proposed and revised structures of graphislactones e and F

Graphislactones A-H and the structurally related ulocladol are highly oxygenated resorcylic lactones produced by lichens and fungi. We present total syntheses of graphislactones A, C-F, H and of ulocladol. Graphislactones E, F, and H were synthesized for the first time. The spectra of graphislactones E and F synthesized as the originally proposed structures were not in agreement with published data. Consequently, revised structures for these compounds are proposed, whose correctness is unambiguously proven by total synthesis and comparison of the spectroscopic data. Key steps in all syntheses are Suzuki couplings for the construction of the central biaryl bond and Dakin reactions to supply further hydroxy groups required in these highly oxygenated substrates. Graphislactones A, C, and H, acylated graphislac- tone D and ulocladol were prepared in 8-11 steps with 7-20% yield starting with purchasable compounds, where the longest linear sequence consists of 5-9 steps. The syntheses are thus significantly shorter than the previously published syntheses of graphislactones A-D and of ulocladol. Graphis- lactones E and F were synthesized in 8 steps, where the longest linear sequences consist of 6 and 5 steps, respectively. They were isolated as the respective acetylated compounds with 25 and 10% yield.

Analogs of 3-hydroxy-1H-1-benzazepine-2,5-dione: Structure-activity relationship at N-methyl-D-aspartate receptor glycine sites

A series of aromatic and azepine ring-modified analogs of 3-hydroxy-1H- 1-benzazepine-2,5-dione (HBAD) were synthesized and evaluated as antagonists at NMDA receptor glycine sites. Aromatic ring-modified HBADs were generally prepared via a Schmidt reaction with substituted 2-methoxynaphthalene-1,4- diones followed by demethylation. Electrophilic aromatic substitution of benzazepine 3-methyl ethers gave 7-substituted analogs. The preparation of multiply substituted 2-methoxynaphthalene-1,4-diones was effected via Diels- Alder methodology utilizing substituted butadienes with 2- methoxybenzoquinones followed by aromatization. Structural modifications, such as elimination of the aromatic ring, removal of the 3-hydroxyl group, and transfer of the hydroxyl group from C-3 to C-4, were also studied. An initial evaluation of NMDA antagonism was performed using a [3H]MK801 binding assay. HBADs demonstrating NMDA antagonist activity as indicated by inhibition of [3H]MK801 binding were further evaluated employing a [3H]- 5,7-dichlorokynurenic acid (DCKA) glycine site binding assay. Selected HBADs were characterized for functional antagonism of NMDA and AMPA receptors using electrophysiological assays in Xenopus oocytes and cultured rat cortical neurons. Antagonist potency of HBADs showed good correlation between the different assay systems. HBADs substituted at the 8-position possessed the highest potency with the 8-methyl (5), 8-chloro (6), and 8-bromo (7) analogs being the most active. For HBAD 6, the IC50 in [3H]-DCKA binding assays was 0.013 μM and the K(b) values for antagonism of NMDA receptors in oocytes (NR1a/2C) and cortical neurons were 0.026 and 0.048 μM, respectively. HBADs also antagonized AMPA-preferring non-NMDA receptors expressed in oocytes but at a lower potency than corresponding inhibition of NMDA receptors. HBADs demonstrating a high potency for NMDA glycine sites showed the highest steady-state selectivity index relative to AMPA receptors. Substitution at the 6-, 7-, and 9-positions generally reduced or eliminated glycine site affinity. Moving the hydroxyl group from C-3 to C-4 reduced receptor affinity, and potency was eliminated by the removal of the aromatic ring or the hydroxyl group. These data indicate that the HBAD series has specific structural requirements for high receptor affinity. With the exception of substitution at C-8, modified HBADs generally have a lower affinity at NMDA receptor glycine sites than the parent compound 3. Mouse maximum electroshock-induced seizure studies show that the three HBADs selected for testing have in vivo potency with the 6,8-dimethyl analog (52) being the most potent (ED50 = 3.9 mg/kg, iv).

AZEPINE SYNTHESIS VIA A DIELS-ALDER REACTION

Disclosed are methods of preparing azepines by a multistep synthesis including a Diels-Alder reaction. Also disclosed are methods of treating or preventing neuronal loss associated with stroke, ischemia, CNS trauma, hypoglycemia and surgery, as well as treating neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease and Down's syndrome, treating or preventing the adverse consequences of the hyperactivity of the excitatory amino acids, as well as treating anxiety, chronic pain, convulsions, inducing anesthesia and treating or preventing opiate tolerance are disclosed by administering to an animal in need of such treatment an azepine which has high binding to the NMDA glycine site.