- Benzoyl-containing rupestonic acid methyl ester derivative as well as preparation method and application thereof
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The invention relates to a benzoyl-containing rupestonic acid methyl ester derivative as well as a preparation method and application thereof. Rupestonic acid and dimethyl sulfate react to obtain rupestonic acid methyl ester, 2-hydroxyl rupestonic acid methyl ester is prepared under oxidation of camphor sulfonyl acridine, and then the 2-hydroxyl rupestonic acid methyl ester reacts with different substituted benzoyl chloride under the catalysis of DMAP to obtain the 1d-15d benzoyl-containing rupestonic acid methyl ester derivative. The method has the advantages of mild reaction conditions and simple experimental steps. The obtained benzoyl-containing rupestonic acid methyl ester derivative 1d-15d is subjected to an anti-H3N2 influenza A virus activity test in 1d-15d. Experimental results show that the compounds 1d, 2d, 4d, 5d, 7d, 8d, 12d, 13d and 15d can be applied to preparation of drugs for resisting influenza A H3N2 virus.
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Paragraph 0032; 0066; 0070
(2021/06/22)
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- One-step Conversion of Amides and Esters to Acid Chlorides with PCl3
-
A general and efficient iodine-promoted chlorination of amides and esters with phosphorus trichloride is described. For the first time. Various inactivated amides including secondary and tertiary amides were directly converted to the corresponding acid chlorides in one-step. The substrate scope of methyl esters including aromatic and aliphatic esters was also explored under this system. This method is simple, scalable and wide in scope, which provides an approach to preparation of these acid chlorides.
- Li, Fangshao,Wu, Xiaofang,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
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supporting information
p. 4314 - 4317
(2021/07/16)
-
- Idnhibition of antibacterial resistance by 3',4'-difluoroquercetin and its derivative
-
The present invention relates to 3andprime;,4andprime;-difluoroquercetin having antibacterial activity on multiple drug resistant bacteria and a novel derivative thereof. A quercetin derivative compound of the present invention exhibits a significant antibacterial activity on Gram-positive multiple drug resistant bacteria, exhibits strong antibacterial activity only on Gram-negative multiple drug resistant bacteria, and a significant synergistic effect occurs when an antibiotic which does not have antibacterial activity or has low antibacterial activity and the compound of the present invention are mixed and treated in Gram-negative multiple drug resistant bacteria, thereby being able to exhibit an excellent antibacterial effect on Gram-positive multiple drug resistant bacteria, Gram-negative multiple drug resistant bacteria, and antibiotic-resistant bacteria thereof.COPYRIGHT KIPO 2020
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Paragraph 0097-0099
(2020/09/16)
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- Discovery of methoxy-naphthyl linked N-(1-benzylpiperidine) benzamide as a blood-brain permeable dual inhibitor of acetylcholinesterase and butyrylcholinesterase
-
The cholinesterase enzymes play a vital role in maintaining balanced levels of the neurotransmitter acetylcholine in the central nervous system. However, the overexpression of these enzymes results in hampered neurotransmission. Both the major forms of cholinesterase enzymes viz. acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) play a crucial role in blocking neurotransmission; therefore, in recent years, a strategy of dual cholinesterase inhibition is being explored. Herein, we developed an energy-optimized e-pharmacophore hypothesis AHHPRR from AChE-donepezil complex and screened a set of 15 scaffolds that were designed imaginarily. The ligand with N-(1-benzylpyridinium) benzamide framework has shown the highest fitness and volume score, which was chosen for synthesis and validation. A series of pyridinium benzamides were synthesized and screened for cholinesterase inhibition that led to the identification of 7b, a naphthalene containing N-(1-benzylpiperidine) benzamide as a potent dual AChE and BChE inhibitor with IC50 values of 0.176, and 0.47 μM, respectively. The kinetic study indicated that 7b inhibits AChE in a non-competitive manner with Ki value of 0.21 μM, and BChE in a mixed-fashion with Ki of 0.15 μM. The observed mode of inhibition was corroborated with molecular docking studies. The MD simulation studies pointed out that both AChE and BChE undergo low conformational changes in complex with 7b. The benzamide 7b displayed high BBB permeability in PAMPA assay, which indicates its potential for further exploration in preclinical studies for Alzheimer's disease.
- Abdullaha, Mohd,Bharate, Sandip B.,Nuthakki, Vijay K.
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-
- Identification of Phenylpyrazolone Dimers as a New Class of Anti-Trypanosoma cruzi Agents
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Chagas disease is becoming a worldwide problem; it is currently estimated that over six million people are infected. The two drugs in current use, benznidazole and nifurtimox, require long treatment regimens, show limited efficacy in the chronic phase of infection, and are known to cause adverse effects. Phenotypic screening of an in-house library led to the identification of 2,2′-methylenebis(5-(4-bromophenyl)-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one), a phenyldihydropyrazolone dimer, which shows an in vitro pIC50 value of 5.4 against Trypanosoma cruzi. Initial optimization was done by varying substituents of the phenyl ring, after which attempts were made to replace the phenyl ring. Finally, the linker between the dimer units was varied, ultimately leading to 2,2′-methylenebis(5-(3-bromo-4-methoxyphenyl)-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one (NPD-0228) as the most potent analogue. NPD-0228 has an in vitro pIC50 value of 6.4 against intracellular amastigotes of T. cruzi and no apparent toxicity against the human MRC-5 cell line and murine cardiac cells.
- Sijm, Maarten,Siciliano de Araújo, Julianna,Ramos Llorca, Alba,Orrling, Kristina,Stiny, Lydia,Matheeussen, An,Maes, Louis,de Esch, Iwan J. P.,de Nazaré Correia Soeiro, Maria,Sterk, Geert Jan,Leurs, Rob
-
supporting information
p. 1662 - 1668
(2019/08/30)
-
- Structural Basis for Achieving GSK-3β Inhibition with High Potency, Selectivity, and Brain Exposure for Positron Emission Tomography Imaging and Drug Discovery
-
Using structure-guided design, several cell based assays, and microdosed positron emission tomography (PET) imaging, we identified a series of highly potent, selective, and brain-penetrant oxazole-4-carboxamide-based inhibitors of glycogen synthase kinase-3 (GSK-3). An isotopologue of our first-generation lead, [3H]PF-367, demonstrates selective and specific target engagement in vitro, irrespective of the activation state. We discovered substantial ubiquitous GSK-3-specific radioligand binding in Tg2576 Alzheimer's disease (AD), suggesting application for these compounds in AD diagnosis and identified [11C]OCM-44 as our lead GSK-3 radiotracer, with optimized brain uptake by PET imaging in nonhuman primates. GSK-3β-isozyme selectivity was assessed to reveal OCM-51, the most potent (IC50 = 0.030 nM) and selective (>10-fold GSK-3β/GSK-3α) GSK-3β inhibitor known to date. Inhibition of CRMP2T514 and tau phosphorylation, as well as favorable therapeutic window against WNT/β-catenin signaling activation, was observed in cells.
- Bernard-Gauthier, Vadim,Mossine, Andrew V.,Knight, Ashley,Patnaik, Debasis,Zhao, Wen-Ning,Cheng, Chialin,Krishnan, Hema S.,Xuan, Lucius L.,Chindavong, Peter S.,Reis, Surya A.,Chen, Jinshan Michael,Shao, Xia,Stauff, Jenelle,Arteaga, Janna,Sherman, Phillip,Salem, Nicolas,Bonsall, David,Amaral, Brenda,Varlow, Cassis,Wells, Lisa,Martarello, Laurent,Patel, Shil,Liang, Steven H.,Kurumbail, Ravi G.,Haggarty, Stephen J.,Scott, Peter J. H.,Vasdev, Neil
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supporting information
p. 9600 - 9617
(2019/10/28)
-
- Design, synthesis, structure-activity relationships study and X-ray crystallography of 3-substituted-indolin-2-one-5-carboxamide derivatives as PAK4 inhibitors
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We have previously described the identification of indolin-2-one-5-carboxamides as potent PAK4 inhibitors. This study expands the structure-activity relationships on our original series by presenting several modifications in the lead compounds, 2 and 3. A series of novel derivatives was designed, synthesized, and evaluated in biochemical and cellular assay. Most of this series displayed nanomolar biochemical activity and potent antiproliferative activity against A549 and HCT116 cells. The representative compound 10a exhibited excellent enzyme inhibition (PAK4 IC50 = 25 nM) and cellular potency (A549 IC50 = 0.58 μM, HCT116 IC50 = 0.095 μM). An X-ray structure of compound 10a bound to PAK4 was obtained. Crystallographic analysis confirmed predictions from molecular modeling and helped refine SAR results. In addition, Compound 10a displayed focused multi-targeted kinase inhibition, good calculated drug-likeness properties. Further profiling of compound 10a revealed it showed weak inhibitory activity against various isoforms of human cytochrome P450.
- Guo, Jing,Zhao, Fan,Yin, Wenbo,Zhu, Mingyue,Hao, Chenzhou,Pang, Yu,Wu, Tianxiao,Wang, Jian,Zhao, Dongmei,Li, Haitao,Cheng, Maosheng
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p. 197 - 209
(2018/06/12)
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- Synthesis and biological evaluation of fluorinated N-benzoyl and N-phenylacetoyl derivatives of 3-(4-aminophenyl)-coumarin-7-O-sulfamate as steroid sulfatase inhibitors
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In the present work, we report convenient methods for the synthesis of 3-(4-aminophenyl)-coumarin-7-O-sulfamate derivatives N-acylated with fluorinated analogues of benzoic or phenylacetic acid as steroid sulfatase (STS) inhibitors. The design of these potential STS inhibitors was supported by molecular modeling techniques. Additionally, computational docking methods were used to determine the binding modes of the synthesized inhibitors and to identify potential interactions between inhibitors and amino acid residues located in the active site of STS. The inhibitory effects of the synthesized compounds were tested on STS isolated from human placenta and against estrogen receptor-(ER)-positive MCF-7 and T47D cells, as well as ER-negative MDA-MB-231 and SkBr3 cancer cell lines. In the course of our investigation, compounds 6c and 6j demonstrated the highest inhibitory effect in enzymatic STS assays, both with IC50values of 0.18?μM (the IC50value of coumarin-7-O-sulfamate is 1.38?μM, used as a reference). Compound 6j exhibited the highest potency against the MCF-7 and T47D cell lines (15.9?μM and 8.7?μM, respectively). The GI50values of tamoxifen (used as a reference) were 6.8; 10.6; 15.1; 12.5?μM against MCF-7, T47D, MDA-MB-231 and SkBr3 cancer cell lines, respectively. Despite the slightly lower activity of compounds 1 and 2 (both in enzymatic and cell-based experiments) compared to 6g and 6j, analogues 1 and 2 proved to selectively inhibit the growth of ER- and PR-positive cell lines.
- Da?ko, Mateusz,Przyby?owska, Maja,Rachon, Janusz,Mas?yk, Maciej,Kubiński, Konrad,Misiak, Majus,Sk?adanowski, Andrzej,Demkowicz, Sebastian
-
-
- Synthesis and biological evaluation of N-acylated tyramine sulfamates containing C–F bonds as steroid sulfatase inhibitors
-
Steroid sulfatase (STS) is responsible for the hydrolysis of biologically inactive sulfated steroids into their active un-sulfated forms and promotes the growth of various hormone-dependent cancers (e.g., breast cancer). Therefore, the STS enzyme is a promising therapeutic target for the treatment of steroid-sensitive cancers. Herein, we report the synthesis and biological evaluation of sulfamate analogs as potential STS inhibitors based on N-acylated tyramines that contain C–F bonds. The inhibitory effects of the analogs were tested using STS isolated from human placenta. Of the analogs tested, 4-(2-perfluoroundecanoylaminoethyl)-phenyl sulfamate, 5r, demonstrated the greatest inhibitory effect, with an IC50 value of 2.18?μm (IC50 value of 2.13?μm for coumarin-7-O-sulfamate was used as a reference). These findings were supported by the results our computational analyses performed using molecular docking techniques.
- Da?ko, Mateusz,Rachon, Janusz,Mas?yk, Maciej,Kubiński, Konrad,Demkowicz, Sebastian
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p. 156 - 161
(2017/06/19)
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- Synthesis, antitumor activity and mechanism of action of novel 1,3-thiazole derivatives containing hydrazide–hydrazone and carboxamide moiety
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A series of novel 2,4,5-trisubstituted 1,3-thiazole derivatives containing hydrazide–hydrazine, and carboxamide moiety including 46 compounds T were synthesized, and evaluated for their antitumor activity in vitro against a panel of five human cancer cell lines. Eighteen title compounds T displayed higher inhibitory activity than that of 5-Fu against MCF-7, HepG2, BGC-823, Hela, and A549 cell lines. Especially, T1, T26 and T38 exhibit best cytotoxic activity with IC50values of 2.21?μg/mL, 1.67?μg/mL and 1.11?μg/mL, against MCF-7, BCG-823, and HepG2 cell lines, respectively. These results suggested that the combination of 1,3-thiazole, hydrazide–hydrazone, and carboxamide moiety was much favorable to cytotoxicity activity. Furthermore, the flow cytometry analysis revealed that compounds T1 and T38 could induce apoptosis in HepG2 cells, and it was confirmed T38 led the induction of cell apoptosis by S cell-cycle arrest.
- He, Haifeng,Wang, Xiaoyan,Shi, Liqiao,Yin, Wenyan,Yang, Ziwen,He, Hongwu,Liang, Ying
-
supporting information
p. 3263 - 3270
(2016/07/12)
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- NOVEL ANTIVIRAL AGENTS AGAINST HBV INFECTION
-
The present invention is directed toward novel compounds and novel methods of use of said compounds of the formula (I), useful as nucleocapsid assembly inhibitors for the treatment of viruses, especially but not exclusively, including pregenomic RNA encapsidation inhibitors of HBV for the treatment of Hepatitis B virus (HBV) infection and related conditions. (Formula (I)) Including hydrates, solvates, pharmaceutically acceptable salts, prodrugs and complexes thereof, wherein A, R1, R2, R3, R4, R5, R6, R7, and R8 are defined herein.
- -
-
Paragraph 0699; 0700
(2014/07/21)
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- Semisynthesis of fluoro-substituted benzoates of Epi-gallocatechin
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In the present study, four fluoro-substituted benzoates of epi-gallocatechin (EGC) were prepared through a semisynthetic strategy, and the yield of benzylation of epi-gallocatechin gallate (-)-EGCG was improved by using freshly purified (-)-EGCG as starting material and a mild base of K 2CO3. All structures of new compounds were characterized by 1H NMR, 13C NMR, high-resolution mass spectrometry, and optical rotation.
- Qin, Xu Long,Li, Xue Min,Yuan, Jian,Chen, Di,Jiang, Tao,Dou, Q. Ping,Chan, Tak Hang,Wan, Sheng Biao
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experimental part
p. 3524 - 3531
(2012/09/25)
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- N -pyridyl and pyrimidine benzamides as KCNQ2/Q3 potassium channel openers for the treatment of epilepsy
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A series of N-pyridyl benzamide KCNQ2/Q3 potassium channel openers were identified and found to be active in animal models of epilepsy and pain. The best compound 12 [ICA-027243, N-(6-chloro-pyridin-3-yl)-3,4-difluoro-benzamide] has an EC50 of 0.38 μM and is selective for KCNQ2/Q3 channels. This compound was active in several rodent models of epilepsy and pain but upon repeated dosing had a number of unacceptable toxicities that prevented further development. On the basis of the structure-activity relationships developed around 12, a second compound, 51, [N-(2-chloro-pyrimidin-5-yl)-3,4-difluoro- benzamide, ICA-069673], was prepared and advanced into a phase 1 clinical study. Herein, we describe the structure-activity relationships that led to the identification of compound 12 and to the corresponding pyrimidine 51.
- Amato, George,Roeloffs, Rosemarie,Rigdon, Greg C.,Antonio, Brett,Mersch, Theresa,McNaughton-Smith, Grant,Wickenden, Alan D.,Fritch, Paul,Suto, Mark J.
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supporting information; experimental part
p. 481 - 484
(2011/08/22)
-
- NOVEL PHENYLPYRROLE DERIVATIVE
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The present invention relates to a compound or a pharmacologically acceptable salt thereof having superior glucokinase activating activity, and is a compound represented by general formula (I), or pharmacologically acceptable salt thereof: [wherein, A represents, for example, an oxygen atom or sulfur atom, R1 represents, for example, a C1-C6 alkyl group, a C1-C6 alkoxy group or a C1-C6 halogenated alkyl group, A and R1 together with the carbon atom bonded thereto form a heterocyclic group that may be substituted with 1 to 3 group(s) independently selected from Substituent Group α, R2 represents a phenyl group that may be substituted with 1 to 5 group(s) independently selected from Substituent Group α or a heterocyclic group that may be substituted with 1 to 3 group(s) independently selected from Substituent Group α, R3 represents a hydroxy group or a C1-C6 alkoxy group, and Substituent Group α consists of, for example, a halogen atom, a C1-C6 alkyl group, a C1-C6 alkyl group substituted with 1 or 2 hydroxy group(s), a C1-C6 alkylsulfonyl group, and a group represented by the formula -V-NR5R6 (wherein, V represents a carbonyl group or a sulfonyl group, and R5 and R6 may be the same or different and respectively represent a hydrogen atom or a C1-C6 alkyl group, or R5 and R6 together with the nitrogen atom bonded thereto form a 4- to 6-membered saturated heterocycle that may be substituted with 1 or 2 group(s) independently selected from a C1-C6 alkyl group and a hydroxy group, and the 4- to 6-membered saturated heterocycle may further contain one oxygen atom or nitrogen atom)].
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Page/Page column 80; 81
(2010/11/03)
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- CYCLOPROPYL BENZAMIDE DERIVATIVES AS INTERMEDIATES FOR CYTOKINE INHIBITORS
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A process for preparing a compound of formula (I) or a pharmaceutically acceptable salt thereof; wherein Qa is as defined in the specification, the compounds being useful in the preparation of therapeutic agents, in particular cytokine inhibitors. Novel compounds of formula (I) are also provided.
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Page/Page column 16
(2009/12/23)
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- Structure-activity relationships comparing N-(6-methylpyridin-yl)- substituted aryl amides to 2-methyl-6-(substituted-arylethynyl)pyridines or 2-methyl-4-(substituted-arylethynyl)thiazoles as novel metabotropic glutamate receptor subtype 5 antagonists
-
The metabotropic glutamate receptor subtype 5 (mGluR5) has been implicated in anxiety, depression, pain, mental retardation, and addiction. The potent and selective noncompetitive mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP, 1) has been a critically important tool used to further elucidate the role of mGluR5 in these CNS disorders. In an effort to provide novel and structurally diverse selective mGluR5 antagonists, we previously described a set of analogues with moderate activity wherein the alkyne bond was replaced with an amide group. In the present report, extended series of both amide and alkyne-based ligands were synthesized. MGluR5 binding and functional data were obtained that identified (1) several novel alkynes with comparable affinities to 1 at mGluR5 (e.g., 10 and 20-23), but (2) most structural variations to the amide template were not well tolerated, although a few potent amides were discovered (e.g., 55 and 56). Several of these novel analogues show drug-like physical properties (e.g., cLogP range = 2-5) that support their use for in vivo investigation into the role of mGluR5 in CNS disorders.
- Kulkarni, Santosh S.,Zou, Mu-Fa,Cao, Jianjing,Deschamps, Jeffrey R.,Rodriguez, Alice L.,Conn, P. Jeffrey,Newman, Amy Hauck
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experimental part
p. 3563 - 3575
(2010/04/05)
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- Synthesis and anti-inflammatory activity of fluorinated isocoumarins and 3,4-dihydroisocoumarins
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The synthesis of several fluorinated isocoumarins and 3,4-dihydroisocoumarins are described. The structures of the synthesized compounds were confirmed by spectral and elemental analysis. All synthesized compounds were evaluated for their anti-inflammatory and antioxidant activity. These compounds were found to present antioxidant and anti-inflammatory activities. A few of them were found to be significantly active in vivo against ear edema in mice produced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and also good radical scavengers.
- Qadeer, Ghulam,Rama, Nasim Hasan,Gardu?o-Ramírez
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p. 641 - 646
(2008/01/06)
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- PYRIMIDINE DERIVATIVES FOR THE INHIBITION OF IGF-IR TYROSINE KINASE ACTIVITY
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A compound of formula (I) wherein the substituents are as defined in the text for use in inhibiting insulin-like growth factor 1 receptor activity in a warm blooded animal such as man.
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-
Page/Page column 107
(2008/06/13)
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- HETROARYL BENZAMIDE DERIVATIVES FOR USE AS GLK ACTIVATORS IN THE TREATMENT OF DIABETES
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Compounds of Formula (I) wherein: R1 is hydroxymethyl; R2 is selected from -C(O)NR4R5, SO2NR4R5, S(O)pR4 and HET-2; HET-1 is a 5- or 6-membered, optionally substituted C-linked heteroaryl ring; HET-2 is a 4-, 5- or 6-membered, C- or N-linked optionally substituted heterocyclyl ring; R3 is selected from halo, fluoromethyl, difluoromethyl, trifluoromethyl, methyl, methoxy and cyano; R4 is selected from for example hydrogen, optionally substituted (1-4C)alkyl and HET-2; R5 is hydrogen or (1-4C)alkyl; or R4 and R5 together with the nitrogen atom to which they are attached may form a heterocyclyl ring system as defined by HET-3; HET-3 is for example an optionally substituted N-linked, 4, 5 or 6 membered, saturated or partially unsaturated heterocyclyl ring; p is (independently at each occurrence) 0, 1 or 2; m is 0 or 1; n is 0, 1 or 2; provided that when m is 0, then n is 1 or 2; or a salt, pro drug or solvate thereof, are described. Their use as GLK activators, pharmaceutical compositions containing them, and processes for their preparation are also described.
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Page/Page column 111-112
(2008/06/13)
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- Structure-activity relationships: Analogues of the dicaffeoylquinic and dicaffeoyltartaric acids as potent inhibitors of human immunodeficiency virus type 1 integrase and replication
-
The dicaffeoylquinic acids (DCQAs) and dicaffeoyltartaric acids (DCTAs) are potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) integrase. They also inhibit HIV-1 replication at nontoxic concentrations. Since integrase is an excellent target for anti-HIV therapy, structure-activity relationships were employed to synthesize compounds with: (1) improved potency against HIV-1 integrase, (2) improved anti-HIV effect in tissue culture, and (3) increased selectivity as indicated by low cellular toxicity. Thirty-four analogues of the DCTAs and DCQAs were synthesized and tested for cell toxicity, anti-HIV activity, and inhibition of HIV-1 integrase. Seventeen of the 34 analogues had potent activity against HIV-1 integrase ranging from 0.07 to > 10 μM. Seventeen analogues that were synthesized or purchased had no inhibitory activity against integrase at concentrations of 25 μM. Of the biologically active analogues, 7 of the 17 inhibited HIV replication at nontoxic concentrations. The most potent compounds were D-chicoric acid, meso-chicoric acid, bis(3,4- dihydroxydihydrocinnamoyl)-L-tartaric acid, digalloyl-L-tartaric acid, bis(3,4-dihydroxybenzoyl)-L-tartaric acid, dicaffeoylglyceric acid, and bis(3,4-dihydroxyphenylacetyl)-L-tartaric acid. Anti-HIV activity of the active compounds in tissue culture ranged from 35 to 0.66 μM. Structure- activity relationships demonstrated that biscatechol moieties were absolutely required for inhibition of integrase, while at least one free carboxyl group was required for anti-HIV activity. These data demonstrate that analogues of the DCTAs and the DCQAs can be synthesized which have improved activity against HIV integrase.
- King, Peter J.,Ma, Guoxiang,Miao, Wenfang,Jia, Qi,McDougall, Brenda R.,Reinecke, Manfred G.,Cornell, Chris,Kuan, Jean,Kim, Tracey R.,Robinson Jr., W. Edward
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p. 497 - 509
(2007/10/03)
-
- Accelerating effect of meta substituents in the ester-mediated nucleophilic aromatic substitution reaction
-
The ester-mediated nucleophilic aromatic substitution (SNAr) reaction of 2-methoxybenzoic ester 1 with Grignard reagents 11 is greatly accelerated by introduction of a methoxy or halo substituent at the 3-position of the benzoate ring (7-10). The substituent effects of these groups at the 3-position are compared with those at the 5-position to suggest that the activation mechanism of the methoxy substituent is different from that of the halo substituent; the ligating ability of the 3-methoxy group plays a crucial role in enhancing the reactivity of the 2-methoxy moiety, while the electron-withdrawing ability is more important in the case of the halo groups. It has also been found that introduction of an additional methoxy substituent at the meta-position (33, 34) enables the SNAr methoxy-displacement reaction even at the para-position to the ester activator. The accelerating effect of the 3-bromo substituent is advantageously utilized for regioselective allylation of 3-bromo-2,6-dimethoxybenzoic ester 55 at the 2-position to provide an easy access to a multisubstituted naphthol 59, which is a key compound for the syntheses of michellamines A-C and the related naphthylisoquinoline alkaloids.
- Hattori, Tetsutaro,Takeda, Ayanobu,Suzuki, Kenji,Koike, Nobuyuki,Koshiishi, Eiji,Miyano, Sotaro
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p. 3661 - 3671
(2007/10/03)
-
- The preparation and characterization of some fluorinated α-aminoarylmethanephosphonic acids
-
α-Aminoarylmethanephosphonic acids have been prepared with a range of fluoro, fluoroalkyl, or fluoroalkoxy substituents in the benzene ring (4-F, 3-F, 2-F, 3,4-F2, F5, 4-CF3, 3-CF3, 4-CF3O, and 3-CF3O). These compounds have relatively low aqueous solubility and their NMR spectra (1H, 13C, 31P and 19F) were therefore recorded in D2O in the presence of an excess of alkali. Under these conditions, the ring substituents appear to have little effect on δp (15-18 ppm), or on the 1H and 13C parameters for the benzylic group (α-CH), which are mainly in the ranges observed for other types of α-aminoarylmethanephosphonic acids under alkaline conditions (δH 3.8-4.0 ppm, 2JPH 15.3-16.5 Hz; δC 57-58 ppm, 1JPC 128-132 Hz). For those examples with fluorine in the ortho position (i.e., the 2-fluoro and pentafluoro derivatives) a slightly higher field chemical shift was observed for the benzylic carbon atom (δC 50-51 ppm). In the fast-atom bombardment mass spectra, pseudo-molecular ions, MH+, and ions resulting from the elimination of phosphorous acid [MH - H3PO3]+, provide a further useful means of chararacterization for these compounds. Key words: Fluorinated aminoarylmethanephosphonic acids, dialkyl N-diphenylmethylaminoaryl-methanephosphonates, NMR spectroscopy, FAB mass spectrometry.
- Green, Donovan St C.,Gruss, Ulrike,Haegele, Gerhard,Hudson, Harry R.,Lindblom, Lars,Pianka, Max
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p. 179 - 207
(2007/10/03)
-
- General and Highly Efficient Syntheses of m-Fluoro Arenes Using Potassium Fluoride-Exchange Method
-
Tetraphenylphosphonium bromide was found to be a suitable catalyst for the reaction of m-nitroaryl derivatives carrying cyano, nitro, chlorocarbonyl, trifluoromethyl, and chlorosulfonyl groups with potassium fluoride in the presence of a stoichiometric amount of phthaloyl dichloride, giving the corresponding m-fluoro aromatic derivatives in good yields.The catalyst was also found to be efficient for the fluorodesulfonylation of m-(fluorosulfonyl)aryl derivatives to afford m-fluoro arenes by the use of a reaction-distillation technique.
- Suzuki, Hiroshi,Yazawa, Naoto,Yoshida, Yasuo,Furusawa, Osamu,Kimura, Yoshikazu
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p. 2010 - 2017
(2007/10/02)
-
- AROMATIC FLUORINE CHEMISTRY. PART 1. 3,4-DIFLUOROBENZOIC ACID AND DERIVATIVES VIA 3,4-DIFLUOROBENZOTRIFLUORIDE
-
The preparation of 3,4-difluorobenzotrifluoride from 3,4-dichlorobenzotrifluoride by a KF exchange reaction is described.The conversion of 3,4-difluorobenzotrifluoride to 3,4-difluorobenzoic acid and derivatives is also reported.
- Pews, R. G.,Gall, J. A.,Little, J. C.
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p. 365 - 370
(2007/10/02)
-
