cas 830-79-5, 2,4,6-Trimethoxybenzaldehyde

Articles about 830-79-5Total 36 be found

Article title
Article abstract
Author
Journal number and time
Download

Visible-Light-Mediated Late-Stage Sulfonylation of Boronic Acids via N-S Bond Activation of Sulfonamides
A visible-light-mediated late-stage arylation of N-S bonds in sulfonamides has been developed with using readily available imines as sulfonyl radical source. Diverse complex sulfones could be synthesized by prefunctionalizaiton and subsequent N-S bond ary
Zhen, Jingsong,Du, Xian,Xu, Xiaohong,Li, Yihui,Yuan, Han,Xu, Dejing,Xue, Can,Luo, Yong
p. 1986 - 1991
(2022/02/07)

Phloroglucinol derivatives as anti-tumor agents: synthesis, biological activity evaluation and molecular docking studies
Phloroglucinol compounds isolated from Dryopteris fragrans (L.) Schott showed a variety of biological activities, such as anticancer and anti-inflammatory. In this study, we have made a number of modifications around the scaffold of phloroglucinol and synthesized phloroglucinol derivatives A1–A9, B1–B9, and C1–C3. We synthesized these compounds and investigated their effect on four human cancer cell lines (A-549, MCF-7, Hela, HepG2 cell lines) via MTT assay in vitro. The results revealed that all compounds exhibited certain antiproliferative activities on cancer cell lines and excellent inhibitory effects on MCF-7, in which compound C2 was the best with the IC50 value of 18.49 μM, exceeding that of 5-fluorouracil. Moreover, the cell apoptosis test showed that compound C2 induced apoptosis in a concentration-dependent manner. Furthermore, the results of molecular docking analysis explained the probable interaction between the active compounds and active sites of target protein 4I22 and 1OG5. [Figure not available: see fulltext.]
Zhang, Fuli,Lai, Qingfu,Lai, Weihong,Li, Ming,Jin, Xiaobao,Ye, Lianbao
p. 165 - 176
(2021/12/02)

The synthesis of atalantrenes B, C and D, styrene-dimers from the seeds of Atalantia monophylla
Concise syntheses of three recently reported natural products from Atalantia monophylla are reported. The syntheses required the preparation and careful dimerization of highly electron rich styrenes under acidic conditions. The present work adds to a growing body of evidence that demonstrates that synthetic utility of chiral phosphoric acids in asymmetric reactions using styrene-type compounds.
Nielsen, Alexander J.,Deng, Zirou,McNulty, James
(2020/12/28)

V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
p. 3594 - 3600
(2021/07/02)

METHODS OF TREATING CANCER WITH SMALL MOLECULE NF-kB INHIBITORS
The present invention provides, inter alia, compounds capable of inhibiting NF-κB. Pharmaceutical compositions containing and methods of using the compounds are also provided herein. Also provided are methods and kits for treating cancer and solid tumors in a subject, as well as methods and kits for inducing cancer cell death and apoptosis of a cancer cell, all utilizing the NF-κB inhibitors described herein.
-
Paragraph 0432

(2019/01/15)

Synthesis of new C-dimethylated chalcones as potent antitubercular agents
A new class of C-dimethylated-chalcones (9a–q) were synthesized by using 2-hydroxy-3,5-dimethyl-4,6-dimethoxy acetophenone as a key intermediate. The compounds were screened for anti-tubercular activity against Mycobacterium tuberculosis strain (H37Rv) by Microplate Alamar Blue assay (MABA) method at a concentration of 100–0.8 μg/mL. The chalcones, 9a, 9b, 9c, 9k, 9o, and 9p were found to have higher antitubercular activity than the standard drugs, while the remaining compounds showed moderate activity. The antitubercular activity of the chalcones, 9b (MIC90 = 3.98 μM) and 9o (MIC90 = 3.84 μM) was found to be more than two-fold more active than the standard drugs, streptomycin (MIC90 = 10.75 μM) and ciprofloxacin (MIC90 = 9.43 μM), while their antitubercular activity was found to be more than six-fold more active than pyrazinamide (MIC90 = 25.38 μM). Further, the molecular docking studies employing Mycobacterium tuberculosis protein tyrosine phosphatase (MtbPtp) was carried out to observe docking scores.
Anandam, Rambabu,Jadav, Surender Singh,Ala, Vasu Babu,Ahsan, Mohamed Jawed,Bollikolla, Hari Babu
p. 1690 - 1704
(2018/05/14)

Synthesis of structurally diverse biflavonoids
Synthetic biflavonoids are associated with interesting biological activities, yet they remain poorly explored within drug discovery. Recent years have witnessed a growing interest in synthetic approaches that can provide access to structurally novel biflavonoids so that the biological usefulness of this compound class can be more fully investigated. Herein, we report upon the exploration of strategies based around Suzuki-Miyaura cross-coupling and alcohol methylenation for the synthesis of two classes of biflavonoids: (i) rare ‘hybrid’ derivatives containing flavonoid monomers belonging to different subclasses, and (ii) homodimeric compounds in which the two flavonoid monomers are linked by a methylenedioxy group. Application of these strategies enabled the preparation of a structurally diverse collection of novel biflavonoids from readily-available starting materials, thereby facilitating the probing of uncharted regions of biologically interesting chemical space.
Sum, Tze Jing,Sum, Tze Han,Galloway, Warren R.J.D.,Twigg, David G.,Ciardiello, Joe J.,Spring, David R.
p. 5089 - 5101
(2018/05/23)

Dryopteris fragrans phloroglucinol compound flavaspidic acid BB and antibacterial application thereof
The invention relates to the technical field of medicine and discloses an antibacterial application of a Dryopteris fragrans phloroglucinol compound flavaspidic acid BB. The invention provides the flavaspidic acid BB obtained by the chemical synthesis method. The flavaspidic acid BB has good antibacterial effects, effectively fills in the application deficiency of the antibacterial natural compound and provides an effective antibacterial solution for drug-resistant bacteria. The experimental results show that the compound has a strong antibacterial effect and good curative effects especially on drug-resistant bacteria.
-
Paragraph 0058; 0066; 0067

(2018/05/24)

Electrophilic Aromatic Formylation with Difluoro(phenylsulfanyl) methane
Difluoro(phenylsulfanyl)methane (PhSCF 2 H) was found to undergo a reaction with aromatic compounds mediated by SnCl 4, through a thionium intermediate characterized by NMR and TD-DFT analyses, leading to the formation of a mixture of S, S ′-diphenyl dithioacetal and aromatic aldehyde which, after oxidative hydrolysis, provides the aromatic aldehyde in good to excellent yields. The salient feature of the present work is the reaction of activated aromatic compounds containing a deactivating ester functional group, leading to the formylated products in good yields.
Betterley, Nolan M.,Kongsriprapan, Sopanat,Chaturonrutsamee, Suppisak,Deelertpaiboon, Pramchai,Surawatanawong, Panida,Pohmakotr, Manat,Soorukram, Darunee,Reutrakul, Vichai,Kuhakarn, Chutima
p. 2033 - 2040
(2018/03/21)

SMALL MOLECULE NF-kB INHIBITORS
The present invention provides, inter alia, compounds capable of inhibiting NF-κB. Pharmaceutical compositions containing and methods of using the compounds are also provided herein.
-
Paragraph 0122

(2017/07/14)

Derivative of loureirin B as well as preparation method and application of derivative
The invention discloses a derivative of loureirin B as well as a preparation method and application of derivative. The derivative of the loureirin B has the structure shown in the description. According to the preparation method disclosed by the invention, the structure of the loureirin B is modified and transformed; the derivative produced by the design retains analgesic activity of the loureirin B; the structural stability of the derivative is far higher than that of the loureirin B; in addition, the activity of a voltage-gated potassium channel Kv1.3 for blocking autoimmune disease is also remarkably improved.
-
Paragraph 0034-0036

(2018/03/01)

A new type of pH-sensitive phospholipid
We describe the synthesis and characterization of a type of pH-sensitive pentaerythritol phospholipids, using a trialkoxybenzylidene acetal as the acid-labile moiety. This lipid was prepared by an eight-step synthesis via a latentiation strategy. Liposomes were prepared via the thin film extrusion method. The changes of liposomal sizes were measured by dynamic light scattering. Content release rates of the liposomes as a function of pH were monitored by using a calcein fluorescence dequenching assay. These results indicated that this new liposomal system was capable of releasing its contents under mildly acidic conditions. At last, in vitro cytotoxicity was assayed against three cell lines, suggesting this type of phospholipids was low toxic.
Zhan, Li,Chang, Shuyuan,Liu, Ting,Yu, Shanbao,Li, Hui,Lu, Minjie,Zhu, Yong,Luo, Yu,Yu, Jiahui,Yang, Fan,Tang, Jie
supporting information
p. 4724 - 4727
(2017/11/17)

One-pot Three-component Synthesis of Furan-based Heterocycles from Benzyl Halides
An efficient and a novel approach for the synthesis of furochromene and furopyran scaffolds are described. Benzyl halides undergo oxidation in Kornblum conditions to give the corresponding aldehydes, which in turn undergo [4?+?1] cycloaddition reaction with isocyanide to afford the corresponding furan derivatives. The significant attraction of this protocol is simple procedure, mild reaction condition, and good yield.
Beerappa, Mallappa,Shivashankar, Kalegowda
p. 2197 - 2205
(2017/07/25)

Substituent Effects on the pH Sensitivity of Acetals and Ketals and Their Correlation with Encapsulation Stability in Polymeric Nanogels
The effect of structural variations in acetal- and ketal-based linkers upon their degradation kinetics is studied through the design, synthesis, and study of six series of molecules, comprising a total of 18 different molecules. Through this systematic study, we show that the structural fine-tuning of the linkers allows access to variations in kinetics of degradation of more than 6 orders of magnitude. Hammett correlations show that the ρ value for the hydrolysis of benzylidene acetals is about ?4.06, which is comparable to an SN1-like process. This shows that there is a strong, developing positive charge at the benzylic position in the transition state during the degradation of acetals. This positively charged transition state is consistent with the relative degradation rates of acetals vs ketals (correlated to stabilities of 1°, 2°, and 3° carboxonium ion type intermediates) and the observed effect of proximal electron-withdrawing groups upon the degradation rates. Following this, we studied whether the degradation kinetics study correlates with pH-sensitive variations in the host-guest characteristics of polymeric nanogels that contains these acetal or ketal moieties as cross-linking functionalities. Indeed, the trends observed in the small molecule degradation have clear correlations with the encapsulation stability of guest molecules within these polymeric nanogels. The implications of this fundamental study extend to a broad range of applications, well beyond the polymeric nanogel examples studied here.
Liu, Bin,Thayumanavan
p. 2306 - 2317
(2017/02/23)

Preparation methods of dracorhodin and salt and intermediates thereof and intermediate compounds
The invention relates preparation methods of dracorhodin and salt and intermediates thereof and intermediate compounds. Synthesis of multifunctional group-substituted benzene ring core structures, that is, the intermediate compounds V, VI and VII is achieved by taking phloroglucinol trimethyl ether as a starting raw material, combining a formylation reaction, a Huang-Minlon reduction method, a methyl ether demethylation reaction, the reaction that benzyl is introduced onto phenolic hydroxyl through benzyl halogen, the reaction that methyl is introduced onto phenolic hydroxyl by taking dimethyl carbonate as a methylation reagent, a debenzylation reaction, a demethylation reaction and the like, utilizing the intramolecular hydrogen bond effect of formyl and phenolic hydroxyl on benzene rings and controlling the proper reaction conditions through proper combinations of the reactions and a protection-deprotection strategy. According to the method, dracorhodin and the salt thereof are synthesized by adopting the raw material which is low in cost, easy to obtain and low in toxicity, the process route is short, the cost is low, the chemical selectivity of all the steps is high, the total yield reaches up to about 10%, the process reproducibility is good, industrialization can be achieved, and the green and economical properties are achieved.
-
Paragraph 0144; 0145; 0146; 0147; 0148

(2017/01/19)

Enantioselective Ring Opening of meso-Epoxides with Silicon Tetrachloride Catalyzed by Pyridine N-Oxides Fused with the Bicyclo[3.3.1]nonane Framework
The synthesis of new chiral Lewis basic organocatalysts that contain pyridine N-oxide moieties fused with the bicyclo[3.3.1]nonane framework is reported. The obtained pyridine N-oxides were employed as catalysts in the enantioselective ring opening of meso-epoxides with silicon tetrachloride. Derivative 1b endowed with two 2,4-diaryl-substituted pyridine N-oxide moieties proved to be a particularly effective catalyst for desymmetrization of norbornene oxide 16i to furnish Wagner-Meerwein rearrangement product 20i in unprecedented 96 % ee. Difunctional congener 3, which is striped of the 4-aryl substituents, exhibited moderate to high levels of asymmetric induction (47-88 % ee) with alicyclic epoxide substrates. Chiral Lewis basic catalysts with pyridine N-oxide moieties fused with a bicyclo[3.3.1]nonane framework were used in the enantioselective ring opening of meso-epoxides. 2,4-Diaryl-substituted N-oxide exhibited excellent asymmetric induction with norbornene oxide (96 % ee), whereas less-substituted congener was most effective with alicyclic epoxide substrates (47-88 % ee).
Neni?kis, Algirdas,Ston?ius, Sigitas
p. 6359 - 6369
(2015/10/06)

Total synthesis of evelynin B and taccabulin D
Concise total syntheses of biosynthetic retro-dihydrochalones evelynin B and taccabulin D isolated from roots and rhizomes of Tacca chantrieri and T. integrifolia, have been achieved from pyrogallol trimethylether in six steps and 1,3,5-trimethoxybenzene in three steps, respectively. A condensation between aldehyde and acetophenone was applied to form chalcone as a key step.
Huang, Yu,Gan, Haifeng,Guo, Kai
p. 458 - 461
(2015/11/03)

Divergent and concise total syntheses of dihydrochalcones and 5-deoxyflavones recently isolated from Tacca species and Mimosa diplotricha
Dihydrochalcones and 5-deoxyflavones are types of compounds possessing various biologically interesting properties. Herein, we report the concise and divergent total syntheses of several naturally occurring dihydrochalcones and 5-deoxyflavones from readily available starting materials. The divergent strategy is based around manipulation of a common chalcone scaffold and features application of Algar-Flynn-Oyamada oxidation and benzoquinone C-H activation methodologies. These are the first reported total syntheses of these biologically interesting compounds and the concise and flexible route should be readily amenable to future analogue generation. Furthermore, this work provides an illustration of the utility of divergent synthesis for the expedient and step-economical preparation of natural product libraries.
Sum, Tze Han,Sum, Tze Jing,Stokes, Jamie E.,Galloway, Warren R.J.D.,Spring, David R.
p. 4557 - 4564
(2015/06/08)

Trifluoromethanesulfonyloxy-group-directed regioselective (3 + 2) cycloadditions of benzynes for the synthesis of functionalized benzo-fused heterocycles
Highly regioselective (3 + 2) cycloadditions of (trifluoromethanesulfonyloxy)benzynes [(triflyloxy)benzynes] with 1,3-dipoles followed by cross-coupling reactions provided multisubstituted benzo-fused heterocycles. The triflyloxy group at the 3-position of benzynes, and even that at the remote 4-position, greatly affected the regiocontrol of the cycloaddition. These groups also served to install other substituents at their ipso-positions.
Ikawa, Takashi,Kaneko, Hideki,Masuda, Shigeaki,Ishitsubo, Erika,Tokiwa, Hiroaki,Akai, Shuji
supporting information
p. 520 - 526
(2015/02/05)

Iron-catalysed oxidative cleavage of lignin and β-O-4 lignin model compounds with peroxides in DMSO
Simple FeCl3-derived iron catalysts are used for the cleavage of β-O-4 linkages in lignin and lignin model compounds. The degradation of the β-O-4 linkages and the resinol structures in both organosolv and kraft lignin was proven by 2D-NMR (HSQC) experiments, and the oxidative depolymerisation of these lignin sources was confirmed by GPC. Key reactive species facilitating this cleavage are methyl radicals generated from H2O2 and DMSO.
Mottweiler, Jakob,Rinesch, Torsten,Besson, Claire,Buendia, Julien,Bolm, Carsten
supporting information
p. 5001 - 5008
(2015/11/16)

Formylation of electron-rich aromatic rings mediated by dichloromethyl methyl ether and TiCl4: Scope and limitations
Here the aromatic formylation mediated by TiCl4 and dichloromethyl methyl ether previously described by our group has been explored for a wide range of aromatic rings, including phenols, methoxy- and methylbenzenes, as an excellent way to produce aromatic aldehydes. Here we determine that the regioselectivity of this process is highly promoted by the coordination between the atoms present in the aromatic moiety and those in the metal core.
Ramos-Tomillero, Iván,Paradís-Bas, Marta,De Pinho Ribeiro Moreira, Ibério,Bofill, Josep María,Nicolás, Ernesto,Albericio, Fernando
supporting information
p. 5409 - 5422
(2015/05/13)

Osmium (VI) catalyzed chemoselective oxidation of allylic and benzylic alcohols
A mild and highly chemoselective approach to oxidation of allylic, electron rich/deficient benzylic, and heterocyclic alcohols employing catalytic quantities of K2[OsO2(OH)4] (3 mol %) and chloramine-T (50 mol %) is described. The protocol offers short reaction times (25 min-2 h), controlled oxidation, and tolerance to a variety of substrates. A systematic mechanistic study based on the LC-ESI-MS/MS reveals the presence of imidotriooxoosmium species which further reacts with alcohol to give the oxidized product.
Devari, Shekaraiah,Deshidi, Ramesh,Kumar, Manjeet,Kumar, Arvind,Sharma, Simmi,Rizvi, Masood,Kushwaha, Manoj,Gupta, Ajai Prakash,Shah, Bhahwal Ali
supporting information
p. 6407 - 6410
(2013/11/19)

A direct and mild formylation method for substituted benzenes utilizing dichloromethyl methyl ether-silver trifluoromethanesulfonate
A silver trifluoromethanesulfonate (AgOTf)-promoted direct and mild formylation of benzenes has been developed. The reaction utilizing dichloromethyl methyl ether (Cl2CHOMe) and AgOTf powerfully formylated various substituted benzenes under temperature conditions as low as -78 C without losing the protecting groups on the phenolic hydroxyl group.
Ohsawa, Kosuke,Yoshida, Masahito,Doi, Takayuki
p. 3438 - 3444
(2013/06/26)

Synthesis and biological evaluation of novel curcumin analogues as anti-inflammatory, anti-cancer and anti-oxidant agents
A series of novel curcumin analogues 5a- m were synthesized by Claisen-Schmidt condensation of various aromatic and heteroaromatic amides of 3-aminoactophenones 4a-m with 3-bromo-2,4,6-trimethoxybenzaldehyde and characterized by IR, 1H NMR and mass spectroscopic analysis and were evaluated for anti-inflammatory, anti-cancer and anti-oxidant activity. Out of the 13 synthesized compounds, compounds 5f, 5j and 5m were excellent inhibitors of TNF-α and IL-6. Compounds 5c, 5e, 5b and 5d showed potent COX-2 inhibition, compounds 5d and 5f have shown good trypsin inhibition and compounds 5e, 5g and 5c exhibited excellent β-glucuronidase inhibition. Compounds 5l and 5m showed potent anti-cancer activity against selected five human cancer cell lines. All the compounds exhibited moderate free radical scavenging activity, while compounds 5a and 5m were excellent OH radical scavengers. Springer Science+Business Media, LLC 2011.
Bandgar, Babasaheb P.,Hote, Baliram S.,Jalde, Shivkumar S.,Gacche, Rajesh N.
p. 3006 - 3014
(2012/10/29)

Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
experimental part
p. 4701 - 4709
(2012/07/28)

CYTOKINE INHIBITORS
The present invention provides compounds represented by general formula (I): wherein, R1; R2, R3, L and T are as defined in the specification, in all their stereoisomeric and tautomeric forms and mixtures thereof in all ratios, and their pharmaceutically acceptable salts, pharmaceutically acceptable solvates, and prodrugs thereof. The invention also relates to processes for the manufacture of compounds of formula (I) and pharmaceutical compositions containing them. The compounds and the pharmaceutical compositions of the present invention are useful in the treatment of a condition or disorder mediated by one or more cytokines selected from Tumor Necrosis Factor-alpha (TNF-oc) and interleukins such as IL-1, IL-6, and IL-8. The present invention further provides a method of treatment of inflammatory disorders by administering a therapeutically effective amount of the said compound of formula (I) or its pharmaceutical composition, to a mammal in need thereof.
-
Page/Page column 42

(2011/10/13)

Orthoamides, LXVII [1]. Bis(diformylamino)methane - A new efficient formylating reagent for aromatic compounds
Formaldehyde reacts with diformamide (10) to give N-(hydroxymethyl) diformamide (11), which upon treatment with thionylchloride yields N-(chlormethyl)diformamide (12) together with small amounts of oxydimethylenebis(diformamide) (13). Various diformylamine derivatives, such as diformylaminomethyl formiate (14), diformylaminomethylisothiocyanate (15) and the N-diformylaminomethylated guanidinium salt 16, can be prepared from 12. Bis(diformylamino) methane (7) can be obtained by the reaction of sodium diformamide (8) with either 1-(chloromethyl)pyridinium chloride (9) or N-(chloromethyl)diformamide (12) in acetonitrile. The action of tris(chloromethyl) amine (18) on sodium diformamide (8) affords tris(diformylaminomethyl)amine (19). The constitution of the compounds 7,11 and 19 was confirmed by crystal structure determination. The nature of the products from the reactions of aromatic compounds with 12 depends on the Lewis acid which is used as activator. Thus the N-benzylformamides 20a, b can be obtained from toluene and mesitylene and 12/BF3-ether, whereas 1,2,4- trimethoxybenzene is formylated by 12/AlCl3 to give the aldehyde 22. Interestingly enough, a novel and efficient formylating reagent resulted from these investigations: bis(diformylamino)methane (7), which can be activated by Lewis acids, e. g. AlCl3. The scope of this procedure is comparable with that of the Olah-formylation method (formylfluoride/BF3).
Kantlehner, Willi,Anders, Ernst,Mezger, Jochen,Stoyanov, Edmont V.,Kre?, Ralf,Wermann, Kurt,Frey, Wolfgang,G?rls, Helmar
experimental part
p. 395 - 406
(2009/01/31)

Films and Particles
Described herein are compounds and processes that can be used to prepare polymer-based films, particles, gels and related compositions, and processes for delivery of agents, and other uses.
-
Page/Page column 44

(2008/06/13)

Lewis acid-promoted imine synthesis by the insertion of isocyanides into C-H bonds of electron-rich aromatic compounds
The Lewis acid-promoted insertion of isocyanides into aromatic C-H bonds is reported. An imine functionality containing an array of N-substituents can be introduced directly into electron-rich aromatics in good yields.
Tobisu, Mamoru,Yamaguchi, Seiji,Chatani, Naoto
p. 3351 - 3353
(2008/02/12)

Sulfur-substituted α-alkyl phenethylamines as selective and reversible MAO-A inhibitors: Biological activities, CoMFA analysis, and active site modeling
A series of phenethylamine derivatives with various ring substituents and with or without N-methyl and/or C-α methyl or ethyl groups was synthesized and assayed for their ability reversibly to inhibit monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B). Several compounds showed potent and selective MAO-A inhibitory activity (IC50 in the submicromolar range) but none showed appreciable activity toward MAO-B. A three-dimensional quantitative structure-activity relationship study for MAO-A inhibition was performed on the series using comparative molecular field analysis (CoMFA). The resulting model gave a cross-validated q2 of 0.72 and showed that in this series of compounds steric properties of the substituents were more important than electrostatic effects. Molecular modeling based on the recently published crystal structure of inhibitor-bound MAO-A provided detailed evidence for specific interactions of the ligands with the enzyme, supported by previous references and consistent with results from the CoMFA. On the basis of these results, structural determinants for selectivity of substituted amphetamines for MAO-A are discussed.
Gallardo-Godoy, Alejandra,Fierro, Angélica,McLean, Thomas H.,Castillo, Mariano,Cassels, Bruce K.,Reyes-Parada, Miguel,Nichols, David E.
p. 2407 - 2419
(2007/10/03)

Some unusual observations in the synthesis of benzofuran based nor-neolignan
Extension of the copper acetylide route to the 2-arylbenzofuran 1 having 2,4-6-oxygenation pattern in the side phenyl ring has led to some unusual observations finally resulting in 8.
Panda,Parthasarathy
p. 628 - 631
(2007/10/03)

Exploitation of aldoxime esters as radical precursors in preparative and EPR spectroscopic roles
Photolyses of aldoxime esters, containing a considerable range of alkyl groups, lead to cleavage of their N-O bonds and formation of aryliminyl and alkyl radicals. The process was found to be favoured by 4-methoxyacetophenone as a photosensitiser and by methoxy substituents in the aryl rings. 4-Nitro- and pentafluoro-substitutions of the aryl rings were, on the other hand, deleterious. The intermediate iminyl radicals, together with primary, secondary and tertiary alkyl radicals were characterised by 9 GHz EPR spectroscopy. Cyclopropyl, CF3, and CCl3 radicals were probably also formed, but were too reactive for direct EPR spectroscopic detection. Photosensitised reaction of benzophenone oxime O-nonanoyl ester produced the diphenylmethaniminoxyl, as well as the expected n-octyl and iminyl radicals. This indicated that O-C bond scission accompanied O-N scission for this ketoxime ester. At higher temperatures the C-centred radicals added to the starting oxime esters to produce alkoxyaminyl radicals that were also spectroscopically detected in some cases. No evidence for abstraction of the iminyl hydrogen by tertbutoxyl radicals was obtained. Instead, the t-BuO radicals added to the C=N double bonds of the oxime esters. Similarly, chlorine abstraction from alkylbenzohydroximoyl chlorides by trimethyltin radicals did not take place. Preparative scale experiments with oxime esters containing suitably unsaturated alkyl groups showed that good yields of cyclised products could be obtained in the presence of the photosensitiser. This process constitutes a general method by which carboxylic acids or acid chlorides can be converted into alkyl radicals and hence to cyclised derivatives.
McCarroll, Andrew J.,Walton, John C.
p. 2399 - 2409
(2007/10/03)

Oxidations of benzyl and phenethyl phenyl sulfides. Implications for the mechanism of the microsomal and biomimetic oxidation of sulfides
The study of the oxidation of 4-methoxyphenethyl phenyl sulfide and 3,4-dimethoxyphenethyl phenyl sulfide with potassium 12-tungstocobalt(III)ate [Co(III)W] suggests that in the radical cations of 3,4,5-(MeO)3PhCH2SPh (4) and 2,4,6(MeO)3PhCH2SPh (5) the positive charge is not localized on the sulfur atom, but in the benzylic aromatic ring. Nevertheless, in the biomimetic and microsomal oxidation of 4 and 5 the products observed are exclusively sulfoxides and sulfones, which appears in contrast with a mechanism involving the formation of an intermediate sulfide radical cation followed by a fast oxygen rebound. A direct oxygen transfer mechanism seems most likely.
Baciocchi, Enrico,Lanzalunga, Osvaldo,Pirozzi, Bruno
p. 12287 - 12298
(2007/10/03)

DIPHENYL ETHERS FROM 2-HYDROXYCHALKONE PRECURSORS OF FLAVYLIUM SALTS
The condensation in alkaline medium of 2-hydroxy-4,6-dimethoxybenzaldehyde with some methoxy-substituted acetophenones did not provide the expected 2-hydroxy-4,6-dimethoxychalcones after acidification of the reaction mixture to pH 3, but products of higher molecular weight having the structure of 2,2'-oxydichalcones, as demonstrated by spectroskopic and chemical evidence.Oxydichalcones were also obtained but in lower yield from the reactions of 2-hydroxybenzaldehyde.These condensation products may originate from the nucleophilic interaction of the hydroxy group of theintermediate 2-hydroxychalcones with the flavylium salts, in turn obtained by cyclization in the acidic medium.
Maccarone, Emanuele,Cuffari, Giuseppe,Passerini, Amedeo,Raymo, Francisco
p. 2401 - 2413
(2007/10/02)

First Reactions of Dialkoxycarbenium Tetrafluoroborates with Pyrroles, 5H-Dibenzazepines, and Electron-Rich Arenes
Pyrrole (2a) and 2,5-dimethylpyrrole (2b) react with the dialkoxycarbenium tetrafluoroborates 1a-1c under kinetic control to yield the corresponding acylpyrrole derivatives. 5H-Dibenzazepine (9a) and the 10,11-dihydro derivative 9b react only with the most elecrophilic of the series of electrophiles tested, namely, diethoxycarbenium tetrafluoroborate (1a), to furnish the corresponding formyl derivatives.Similarly, in arene chemistry, the highly electron-rich N,N-dimethylaniline (13a) and 1,3,5-trimethoxybenzene (13b) are formylated by reaction with 1a.
Pindur, U.,Flo, C.
p. 1563 - 1568
(2007/10/02)

Depsidone Synthesis. Part 21. A New Synthesis of Grisa-2',5'-diene-3,4'-diones
Treatment of suitably substituted methyl 2-phenoxybenzoates with titanium(IV) chloride and dry hydrogen chloride afforded grisa-2',5'-diene-3,4'-diones in high yield.The structures of these compounds followed from their thermal stability, their methanolysis to methyl 2-(4-hydroxyphenoxy)benzoates, and their reductive cleavage to 2,4'-dihydrobenzophenones.Treatment of the benzophenones with base gave xanthones.An attempt to synthesize dehydrogriseofulvin (1) by this method failed.
Sargent, Melvyn V.
p. 403 - 411
(2007/10/02)