- Tunable Electrosynthesis of Anthranilic Acid Derivatives via a C-C Bond Cleavage of Isatins
-
A facile and direct electrocatalytic C-C bond cleavage/functionalization reaction of isatins was developed. With isatins as the amino-attached C1 sources, a variety of aminobenzoates, and aminobenzamides were synthesized in moderate to good yields under mild conditions.
- Qian, Peng,Liu, Jiaojiao,Zhang, Yan,Wang, Zhiyong
-
p. 16008 - 16015
(2021/07/31)
-
- A novel pathway for the thermolysis of N-nitrosoanthranilates using flash vacuum pyrolysis leading to 7-aminophthalides
-
Flash vacuum pyrolysis of methyl N-methyl-N-nitrosoanthranilate leads to elimination of nitric oxide and disproportionation of the formed N-radical to 7-(methylamino)phthalide and methyl N-methylanthranilate. This transformation was found to be a convenient, solvent-free method for the preparation of 7-(methylamino)phthalides. An alternative route through pyrolysis of N-benzyl-N-methyl anthranilates was also investigated. This journal is
- Dallinger, Doris,Kappe, C. Oliver,Zlatkovi?, Dragan
-
supporting information
p. 8371 - 8375
(2020/11/05)
-
- Scaffold Hopping of Natural Product Evodiamine: Discovery of a Novel Antitumor Scaffold with Excellent Potency against Colon Cancer
-
Inspired by the natural product evodiamine, a novel antitumor indolopyrazinoquinazolinone scaffold was designed by scaffold hopping. Structure-activity relationship studies led to the discovery of compound 15j, which shows low nanomolar inhibitory activity against the HCT116 cell line. Further antitumor mechanism studies indicated that compound 15j acted by the dual inhibition of topoisomerase 1 and tubulin and induced apoptosis with G2 cell-cycle arrest. The quaternary ammonium salt of compound 15j (compound 15js) exhibited excellent in vivo antitumor activity (TGI = 66.6%) in the HCT116 xenograft model with low toxicity. Indolopyrazinoquinazolinone derivatives represent promising multitargeting antitumor leads for the development of novel antitumor agents.
- Wang, Lei,Fang, Kun,Cheng, Junfei,Li, Yu,Huang, Yahui,Chen, Shuqiang,Dong, Guoqiang,Wu, Shanchao,Sheng, Chunquan
-
p. 696 - 713
(2020/02/04)
-
- PYRIMIDINE SEVEN-MEMBERED-RING COMPOUNDS, PREPARATION METHOD THEREFOR, PHARMACEUTICAL COMPOSITION THEREOF, AND USES THEREOF
-
The present invention relates to compounds (I) capable of inhibiting the Mstl/2 protein kinase activity, a preparation method therefor, a pharmaceutical composition comprising the compounds, and uses of the compounds and the pharmaceutical composition comprising the compounds in the preparation of drugs for prompting repair and regeneration of tissues and organs, prompting stem cell proliferation and somatic cell dedifferentiation, immunosuppression, and preventing or treating diseases related to nervous disorders and local ischemia.
- -
-
Paragraph 0192; 0193
(2019/01/17)
-
- Chemoselectivity for Alkene Cleavage by Palladium-Catalyzed Intramolecular Diazo Group Transfer from Azide to Alkene
-
Alkenes can be cleaved by means of the (3+2) cycloaddition and subsequent cycloreversion of 1,3-dipoles, classically ozone (O3), but the azide (R?N3) variant is rare. Chemoselectivity for these azide to alkene diazo group transfers (DGT) is typically disfavored, thus limiting their synthetic utility. Herein, this work discloses a palladium-catalyzed intramolecular azide to alkene DGT, which grants chemoselectivity over competing aziridination. The data support a catalytic cycloreversion mechanism distinct from other known metal-catalyzed azide/alkene reactions: nitrenoid/metalloradical and (3+2) cycloadditions. Kinetics experiments reveal an unusual mechanistic profile in which the catalyst is not operative during the rate-controlling step, rather, it is active during the product-determining step. Catalytic DGT was used to synthesize N-heterocyclic quinazolinones, a medicinally relevant structural core. We also report on the competing aziridination and subsequent ring expansion to another N-heterocyclic core structure of interest, benzodiazepinones.
- Frost, Grant B.,Mittelstaedt, Michaela N.,Douglas, Christopher J.
-
p. 1727 - 1732
(2019/01/09)
-
- Halogen-substituted anthranilic acid derivatives provide a novel chemical platform for androgen receptor antagonists
-
Androgen receptor (AR) antagonists are used for hormone therapy of prostate cancer (PCa). However resistance to the treatment occurs eventually. One possible reason is the occurrence of AR mutations that prevent inhibition of AR-mediated transactivation by antagonists. To offer in future more options to inhibit AR signaling, novel chemical lead structures for new AR antagonists would be beneficial. Here we analyzed structure-activity relationships of a battery of 36 non-steroidal structural variants of methyl anthranilate including 23 synthesized compounds. We identified structural requirements that lead to more potent AR antagonists. Specific compounds inhibit the transactivation of wild-type AR as well as AR mutants that render treatment resistance to hydroxyflutamide, bicalutamide and the second-generation AR antagonist enzalutamide. This suggests a distinct mode of inhibiting the AR compared to the clinically used compounds. Competition assays suggest binding of these compounds to the AR ligand binding domain and inhibit PCa cell proliferation. Moreover, active compounds induce cellular senescence despite inhibition of AR-mediated transactivation indicating a transactivation-independent AR-pathway. In line with this, fluorescence resonance after photobleaching (FRAP) - assays reveal higher mobility of the AR in the cell nuclei. Mechanistically, fluorescence resonance energy transfer (FRET) - assays indicate that the amino-carboxy (N/C)-interaction of the AR is not affected, which is in contrast to known AR-antagonists. This suggests a mechanistically novel mode of AR-antagonism. Together, these findings indicate the identification of a novel chemical platform as a new lead structure that extends the diversity of known AR antagonists and possesses a distinct mode of antagonizing AR-function.
- Roell, Daniela,R?sler, Thomas W.,Hessenkemper, Wiebke,Kraft, Florian,Hauschild, Monique,Bartsch, Sophie,Abraham, Tsion E.,Houtsmuller, Adriaan B.,Matusch, Rudolf,van Royen, Martin E.,Baniahmad, Aria
-
-
- Acetylhydrazone-based compounds and preparation method thereof
-
The invention discloses acetylhydrazone-based compounds and a preparation method thereof. The acetylhydrazone-based compounds are 2-(1-methyl-6-chloro-2,4 (1H, 3H)-quinazolinedione) acetylhydrazone-based compounds expressed by a general formula I. In-vitro antimicrobial activity tests find that the acetylhydrazone-based compounds have certain inhibitory activity on gram-positive bacteria (staphylococcus aureus, methicillin-resistant staphylococcus aureus and bacillus subtilis), gram-negative bacteria (escherichia coli, proteusbacillus vulgaris and pseudomonas aeruginosa), and fungi (candida albicans, aspergillus flavus, aspergillus fumigatus and cryptococcus neoformans), and some compounds have the inhibitory activity on some tested strains that is close and even prior to the inhibitory activity of the existing drug streptomycin sulfate polyoxin B, so that the compounds can be used for preparing antibacterial and/or antifungal drugs. The preparation method for the compounds is simple, the raw materials are easily available, and the cost is relatively low.
- -
-
Paragraph 0072; 0073; 0074; 0075
(2017/08/25)
-
- Investigation into the stability and reactivity of the pentacyclic alkaloid dehydroevodiamine and the benz-analog thereof
-
Limited synthetic approaches to obtain the biologically active alkaloid dehydroevodiamine (DHED) are known to date. Undesired demethylation in the most widely applied route was found to be a hampering side reaction for the benz-DHED derivative leading to a quinazolinone, which represents a benz-rutaecarpine derivative. For rutaecarpine, a related plant alkaloid, many different synthetic approaches have been described. Alternative reaction procedures to obtain DHED such as methylation of rutaecarpine and oxidation of evodiamine were investigated to make DHED more easily accessible and the latter method proved to be the most successful one. Furthermore, the remarkable equilibrium between the ring closed quinazolinium and the ring open form of the compounds was systematically investigated by UV-vis measurements. The ring open form and the quinazolinium salt, form the same species when incubated in buffer solution for 24 h. A better soluble form, i.e., 'hydroxyevodiamine', seems to represent the biologically active form that has not yet been described.
- Wehle, Sarah,Espargaró, Alba,Sabaté, Raimon,Decker, Michael
-
supporting information
p. 2535 - 2543
(2016/04/26)
-
- Indolo hexahydropyrazino quinazolinones anti-tumor compound and its preparation method
-
The invention relates to the technical field of medicines and in particular relates to indol-hexahydropyrazine-quinazolinone anti-tumour compounds and a preparation method thereof. A chemical structural formula of the indol-hexahydropyrazine-quinazolinone anti-tumour compounds is shown in a genera formula I or a genera formula II, the indol-hexahydropyrazine-quinazolinone anti-tumour compounds are evodiamine new skeleton compounds obtained by carrying out systematic skeleton transition design and synthesis on evodiamine, are newfound topoisomerase I/microtubulin dual inhibitors with a brand new structure and have obvious anti-tumour activity. The invention also provides application of the indol-hexahydropyrazine-quinazolinone anti-tumour compounds in preparation of topoisomerase I/microtubulin dual inhibitors and antitumour drug. The general formula (I) and the general formula (II) are described in the specification.
- -
-
Paragraph 0098-0099
(2017/01/02)
-
- Copper-Catalyzed O-Methylation of Carboxylic Acids Using DMSO as a Methyl Source
-
A copper-catalyzed O-methylation of carboxylic acids using dimethyl sulfoxide (DMSO) as the methyl source is disclosed. This transformation exhibits a broad substrate scope and excellent functional group tolerance. Mechanistic studies indicate that a methyl radical is generated from dimethyl sulfoxide in the reaction process.
- Jia, Jing,Jiang, Qing,Zhao, An,Xu, Bin,Liu, Qiang,Luo, Wei-Ping,Guo, Can-Cheng
-
p. 421 - 428
(2016/01/28)
-
- Structural elucidation of thermolysis products of methyl N-methyl-N-nitrosoanthranilate
-
Although it is common knowledge that N-nitroso compounds are thermally (and otherwise chemically) labile, little or nothing is known about the specific reactions that occur during thermal treatment of a compound possessing this functionality. Methyl N-met
- Miltojevi?, Ana B.,Radulovi?, Niko S.
-
p. 53569 - 53585
(2015/06/30)
-
- Palladium-catalyzed oxidative carbonylation of aromatic C-H bonds of N -alkylanilines with CO and alcohols for the synthesis of o -aminobenzoates
-
A Pd(II)-catalyzed C-H monocarbonylation of N-alkylanilines for the synthesis of o-aminobenzoates has been developed. Various aliphatic alcohols and phenol were tolerated in the reaction to afford the corresponding o-aminobenzoates in good yields under mild balloon pressure of CO.
- Chen, Ming,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
-
p. 1258 - 1263
(2015/01/30)
-
- The effect of hydrogen bond on Br?nsted acid-catalyzed intramolecular hydroamination of unfunctionalized olefins
-
The catalytic activity of benzoic acid could be increased by introducing a hydrogen bond donor group at the ortho-position. Preliminary DFT calculation indicated that the activation of CC double bond was realized by the action of both the carboxyl group and the hydrogen bond donor. The amino group was brought to the activated CC bond by the interaction between the carboxyl oxygen and amino proton. This interaction also increased the nucleophilicity of the amino group. Thus, in the presence of 20 mol % of 2-(trifluoromethanesulfonamido)benzoic acid, intramolecular hydroamination of unfunctionalized olefins gave the corresponding products in up to 95% isolated yields.
- Li, Ting-Ting,Liu, Gong-Qing,Wang, Yu-Mei,Cui, Bin,Sun, Hui,Li, Yue-Ming
-
supporting information
p. 7003 - 7009
(2015/08/19)
-
- INHIBITORS OF HISTONE DEACETYLASE
-
This invention provides compounds that are inhibitors of HDAC2. The compounds (e.g., compounds according to Formula (I), (II), (IIa), (III), (IV), (V), or (VI)) accordingly are useful for treating, alleviating, or preventing a condition in a subject such as a neurological disorder, memory or cognitive function disorder or impairment, extinction learning disorder, fungal disease or infection, inflammatory disease, hematological disease, or neoplastic disease, or for improving memory or treating, alleviating, or preventing memory loss or impairment.
- DEY Fabian,JEFSON Martin R.,KONIG VON PAUMBSHAUSEN Konstanze,SCHOMBURG Adrian,SCHOOP Andreas,THOMAS Russell John
-
Paragraph 0332
(2016/04/26)
-
- Rhodium(III)-Catalyzed Direct Cyanation of Aromatic C-H Bond to Form 2-(Alkylamino)benzonitriles Using N-Nitroso As Directing Group
-
2-(Alkylamino)benzonitriles were synthesized via a rhodium-catalyzed cyanation on the aryl C-H bond and subsequent denitrosation of N-nitrosoarylamines using a removable nitroso as the directing group, in which N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) was used as the "CN" source. Various substituents on the aryl ring and amino group of N-nitrosoarylamines tolerated the reaction, and the corresponding products were achieved in moderate to good yields.
- Dong, Jiawei,Wu, Zhongjie,Liu, Zhengyi,Liu, Ping,Sun, Peipei
-
p. 12588 - 12593
(2016/01/09)
-
- Design, synthesis, and evaluation of novel 1-methyl-3-substituted quinazoline-2,4-dione derivatives as antimicrobial agents
-
A series of novel 1-methyl-3-substituted quinazoline-2,4-dione derivatives was designed, synthesized, and evaluated for their antimicrobial activities against six strains of bacteria and five fungi in vitro. The synthesized compounds were characterized by spectral methods. The bioactive assays showed that most of the compounds exhibited moderate antimicrobial activities against the tested strains. Springer Science+Business Media 2013.
- Ji, Qing-Gang,Yang, Dan,Deng, Qiao,Ge, Zhi-Qiang,Yuan, Lv-Jiang
-
p. 2169 - 2177
(2014/05/06)
-
- Kinetics and mechanism of the base-catalyzed oxygenation of 1H-2-phenyl-3-hydroxy-4-oxoquinolines in DMSO/H2O
-
The oxygenation of 4′-substituted 1H-2-phenyl-3-hydroxy-4- oxoquinolines (PhquinH2) in a DMSO/H2O (50/50) solution leads to the cleavage products at the C2-C3 bond in about 75% yield at room temperature. The oxygenation, deduced from the product compositions, has two main pathways, one proceeding via an endoperoxide leading to CO-release, and the other through a 1,2-dioxetane intermediate without CO-loss. The reaction is specific base-catalyzed and the kinetic measurements resulted in the rate law -a...?[PhquinH2]/a...?t=kOH - [OH-] [PhquinH2] [O2]. The rate constant, activation enthalpy, and entropy at 303.16 K are as follows: kOH-=(2.42±0.03)×103mol -2L2s-1; ΔG?=73. 13±4.02 kJ mol-1; ΔH?=70.60±4. 04 kJ mol-1; ΔS?=-28±2 J mol -1 K-1. The reaction fits a Hammett linear free energy relationship for 4′-substituted substrates, and electron-releasing groups make the oxygenation reaction faster (ρ=-0.258). The EPR spectrum of the reaction mixtures showed the presence of the organic radical 1H-2-phenyl-3-oxyl-4-oxoquinoline and superoxide ion due to single electron transfer from the carbanion to dioxygen. The pathway via 1,2-dioxetane could be proved by chemiluminescence measurements.
- Czaun, Miklós,Speier, Gábor,Kaizer, József,El Bakkali-Taheri, Nadia,Farkas, Etelka
-
supporting information
p. 6666 - 6672
(2013/07/26)
-
- Anthranilic acid-based inhibitors of phosphodiesterase: Design, synthesis, and bioactive evaluation
-
Our previous studies identified two 2-benzoylaminobenzoate derivatives 1, which potently inhibited superoxide (O2-) generation induced by formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP) in human neutrophils. In an attempt to improve their activities, a series of anthranilic acid derivatives were synthesized and their anti-inflammatory effects and underlying mechanisms were investigated in human neutrophils. Of these, compounds 17, 18, 46, 49, and 50 showed the most potent inhibitory effect on FMLP-induced release of O2- in human neutrophils with IC50 values of 0.20, 0.16, 0.15, 0.06, and 0.29 μM, respectively. SAR analysis showed that the activities of most compounds were dependent on the ester chain length in the A ring. Conversely, a change in the linker between the A and B ring from amide to sulfonamide or N-methyl amide, as well as exchanges in the benzene rings (A or B rings) by isosteric replacements were unfavorable. Further studies indicated that inhibition of O2- production in human neutrophils by these anthranilic acids was associated with an elevation in cellular cAMP levels through the selective inhibition of phosphodiesterase 4. Compound 49 could be approved as a lead for the development of new drugs in the treatment of neutrophilic inflammatory diseases.
- Cheng, Yih-Dih,Hwang, Tsong-Long,Wang, Han-Hsiang,Pan, Tai-Long,Wu, Chin-Chung,Chang, Wen-Yi,Liu, Yi-Ting,Chu, Tzu-Chi,Hsieh, Pei-Wen
-
experimental part
p. 7113 - 7125
(2011/11/04)
-
- Identification of a new antinociceptive alkaloid isopropyl N-methylanthranilate from the essential oil of Choisya ternata Kunth
-
Ethnopharmacological relevance: Mexican people employed infusion of leaves of Choisya ternata Kunth for their antispasmodic and "simulative properties". Aim of the study: In the present study the detailed GC and GC-MS analyses of the essential oil of Choisya ternata Kunth (Rutaceae) were performed. The presence of a minor constituent isopropyl N-methylanthranilate (1) was revealed among other identified volatiles. A synthesis of 1 was undertaken in order to corroborate this find and obtain gram quantities that would allow the testing of its biological activity (peripheral and central antinociceptive activity). Materials and methods: The oils were investigated by GC and GC-MS. Synthesized compounds were spectrally characterized (UV-Vis, IR, 1D and 2D NMR, MS). The obtained synthetic samples of compounds were assayed for peripheral and central antinociceptive activity in two models (effects on acetic acid induced writhing in mice and the hot plate test for nociception). Results: Detailed GC and GC-MS analyses of the essential oil of Choisya ternata Kunth (Rutaceae) among 157 other identified volatiles revealed the presence of a minor constituent isopropyl N-methylanthranilate (1). Compound 1, named ternanthranin, is therefore detected as a natural product for the first time with a very restricted occurrence (samples of several citrus oils were screened for the presence of 1). The antinociceptive activities were assayed for ternanthranin, the two other synthetic analogs, methyl and propyl N-methylanthranilate, as well as the essential oil and the crude ethanol extract of the leaves. The results clearly demonstrate a very high (even significant at 0.3 mg/kg) dose dependent activity for the anthranilates (and the extracts). Isopropyl N-methylanthranilate showed the highest, while methyl N-methylanthranilate showed the lowest activity (with the methyl ester at 3 mg/kg still better than acetylsalicylic acid, at 200 mg/kg, in the first, or comparable with morphine, at 5 mg/kg, in the second test). Conclusion: This study once again revealed that detailed investigations of plant species with ethnopharmacologically documented activity may yield new natural compounds - a new alkaloid (ternanthranin), a volatile simple anthranilate that can be considered responsible for the antinociceptive activity of the crude plant extracts.
- Radulovi?, Niko S.,Miltojevi?, Ana B.,McDermott, Michael,Waldren, Steve,Parnell, John Adrian,Pinheiro, Mariana Martins Gomes,Fernandes, Patricia Dias,De Sousa Menezes, Fabio
-
experimental part
p. 610 - 619
(2012/04/23)
-
- Anion binding of N-(o-Methoxybenzamido)thioureas: Contribution of the intramolecular hydrogen bond in the N-benzamide moiety
-
N-(o-Methoxybenzamido)- thioureas (2X/2Y) are found to show an enhanced anion binding affinity with binding constants over 107 mol -1L orders of magnitude for AcO- and a redshifted absorption of the anion binding complexes in acetonitrile (MeCN) relative to those of N-benzamidothioureas (1) that bear no o- OMe in the N-benzamide moiety, despite the electron-donating character of o-OMe. Absorption of the anion-2X/ 2Y complex was shown to be of the same charge-transfer nature as that of the anion-1 complex, but its dependence on substituent X is interestingly influenced by the o-MeO···HNC=O six-membered-ring intramolecular hydrogen bond identified in 2X/2Y. Such an intramolecular hydrogen bond is suggested to be responsible for the enhanced anion binding affinity. In the presence of this intramolecular hydrogen bond, the anion binding constant of 2X was found to be independent of substituent X at the N-phenyl ring, as in the case of 1, whereas that of 2Y showed an amplified dependence on substituent Y at the N′-phenyl ring, but to a lower extent than that of 1. A similar ring intramolecular hydrogen bond was purported to exist in 2Za, 2Zd, and 2Ze, which bear NHMe, F, and Cl as the ortho substituent in the N-benzamide moiety. In terms of the current roles of thiourea in not only anion recognition and sensing but also organocatalysis and crystal engineering, the present finding would be of significance for a wider structural diversity of smart thiourea derivatives with predesigned functions.
- Jiang, Qian-Qian,Darhkijav, Burenkhangai,Liu, Hao,Wang, Fang,Li, Zhao,Jiang, Yun-Bao
-
experimental part
p. 543 - 549
(2010/08/20)
-
- Selective monomethylation of anilines by Cu(OAc)2-promoted cross-coupling with MeB(OH)2
-
N-Methylanilines are readily synthesized in high yields through the copper(ll)-promoted coupling of anilines and methylboronic acid. This method represents a new approach for the selective monomethylation of anilines, and it is the first reported example
- Gonzalez, Israel,Mosquera, Jesus,Guerrero, Cesar,Rodriguez, Ramon,Cruces, Jacobo
-
supporting information; experimental part
p. 1677 - 1680
(2009/09/06)
-
- Synthesis of xanthones, thioxanthones, and acridones by the coupling of arynes and substituted benzoates
-
The reaction of silylaryl triflates, CsF, and ortho-heteroatom-substituted benzoates affords a general and efficient way to prepare biologically interesting xanthones, thioxanthones, and acridones. This chemistry presumably proceeds by a tandem intermolecular nucleophilic coupling of the benzoate with an aryne and a subsequent intramolecular electrophilic cyclization.
- Zhao, Jian,Larock, Richard C.
-
p. 583 - 588
(2007/10/03)
-
- Selective N,N-dimethylation of primary aromatic amines with methyl alkyl carbonates in the presence of phosphonium salts
-
In the presence of onium salts, at 140-170 °C. methyl alkyl carbonates [1a-c, ROCO2Me, R = MeO(CH2)2[O(CH 2)2]n; n = 2-0, respectively] react with primary aromatic amines (XC6H4NH2, X = p-OMe, p-Me, H, p-Cl, p-CO2Me, o-Et, and 2,3-Me2C 6H3NH2) to yield the corresponding N,N-dimethyl derivatives (ArNMe2) with high selectivity (up to 96%) and good isolated yields (78-95%). Phosphonium salts (e.g., Ph3PEtI and n-Bu4PBr) are particularly efficient catalysts. Overall, a solvent-free reaction is coupled with safe methylating agents (1a-c) made from nontoxic dimethyl carbonate.
- Selva, Maurizio,Perosa, Alvise,Tundo, Pietro,Brunelli, Davide
-
p. 5770 - 5773
(2007/10/03)
-
- Mono-N-methylation of functionalized anilines with alkyl methyl carbonates over NaY faujasites. 4. Kinetics and selectivity
-
(Chemical Equation Presented) In the presence of NaY faujasite as the catalyst, the reaction of bifunctional anilines (1-4: XC6H 4-NH2; X = OH, CO2H, CH2OH, and CONH2) with methyl alkyl carbonates [MeOCO2R′: R′ = Me or MeO(CH2)2O(CH2)2] proceeds with a very high mono-N-methyl selectivity (XC6H 4NHMe up to 99%), and chemoselectivity as well, with other nucleophilic functions (OH, CO2H, CH2OH, CONH2) fully preserved from alkylation and/or transesterification reactions. Aromatic substituents, however, modify the relative reactivity of amines 1-4: good evidence suggests that, not only steric and electronic effects, but, importantly, direct acid-base interactions between substituents and the catalyst are involved. Weakly acidic groups (OH, CH2OH, CONH2, pKa ≥ 10) may help the reaction, while aminobenzoic acids (pK a of 4-5) are the least reactive substrates. The solvent polarity also affects the reaction, which is faster in xylene than in the more polar diglyme. The mono-N-methyl selectivity is explained by the adsorption pattern of reagents within the zeolite pores: a BAl2 displacement of the amine on methyl alkyl carbonate should occur aided by the geometric features of the NaY supercavities. Different factors account for the reaction chemoselectivity. Evidence proves that the polarizability of the two nucleophilic terms (NH 2 and X groups) of anilines is relevant, although adsorption and confinement phenomena of reagents promoted by the zeolite should also be considered.
- Selva, Maurizio,Tundo, Pietro,Foccardi, Tommaso
-
p. 2476 - 2485
(2007/10/03)
-
- An Investigation of the Reaction of 2-Aminobenzaldehyde Derivatives with Conjugated Nitro-olefins: An Easy and Efficient Synthesis of 3-Nitro-1,2-dihydroquinolines and 3-Nitroquinolines
-
2-Aryl-3-nitro-1,2-dihydroquinolines 3 were prepared from the reaction of β-nitrostyrenes 2 and 2-aminobenzaldehyde 1 in the presence of DABCO. Not only β-nitrostyrenes but other alkyl nitro olefins also can be used in this reaction as well. When DDQ or silica gel was added to a solution of 3-nitro-1,2-dihydroquinolines 3, 3-nitro-2-substituted-quinolines 4 were obtained. When 2-aminobenzaldehyde derivatives 7 and 12 were reacted with β-nitrostyrenes 2, unique rearrangement products were produced.
- Yan, Ming-Chung,Tu, Zhijay,Lin, Chunchi,Ko, Shengkai,Hsu, Jianming,Yao, Ching-Fa
-
p. 1565 - 1570
(2007/10/03)
-
- Novel 1,3- spirocyclization reaction in the photochemistry of anthranilic acid derivatives in acetonitrile
-
Anthranilic acid derivatives 1a-c were irradiated in acetonitrile solution to give imines (rearranged products) 2a-c in each case. In the case of 1c, a diastereomeric mixture of dl- and meso-dibenzoate derivative (dimerization product) 3c was also obtaine
- Sharshira, Essam Mohamed
-
p. 527 - 534
(2007/10/03)
-
- Photooxygenation of the C=N bond: A mild new method for oxidative C-C cleavage
-
Upon photooxygenation in the presence of base, α-oximinocarbonyl compounds undergo clean oxidative C-C cleavage giving rise to mixtures of esters and acids. The mechanism of these reactions involves some unusual peroxidic intermediates, including a 2,3,5-trioxapentanes.
- ?cal, Nüket,Yano, Lovelle M.,Erden, Ihsan
-
p. 6947 - 6949
(2007/10/03)
-
- Ketone precursors for organoleptic compounds
-
The invention discloses ketones of formula I: wherein, Y is an optionally substituted alkyl, cycloalkyl, or cycloalkylalkyl, wherein each alkyl group is straight or branched and each alkyl and cycloalkyl group is saturated or unsaturated; R1is hydrogen or a C1-6alkyl group that is substituted, saturated or unsaturated, straight or branched; A is a chromophoric substituted aromatic ring or ring system; n is an integer; and with the proviso that formula I is not 2-ethoxy-1-phenyl-ethanone. These compositions are useful for the delivery of organoleptic compounds, especially of flavors, fragrances, masking agents and antimicrobial compounds.
- -
-
-
- Solution-phase combinatorial synthesis of 4-hydroxyquinolin-2(1H)-ones
-
Ion-exchange resins catalyse an intramolecular Claisen-type condensation leading to the title compounds, and also serve to purify the products.
- Kulkarni, Bheemashankar A.,Ganesan
-
p. 785 - 786
(2007/10/03)
-
- Selective mono-N-methylation of primary aromatic amines by dimethyl carbonate over faujasite X- and Y-type zeolites
-
The reaction of dimethyl carbonate (DMC) with different primary aromatic amines has been investigated under batch conditions (autoclave) in the presence of Y- and X-type zeolites. Operating at 120-150°C, highly selective mono-N-methylations are observed for anilines even when they are deactivated by either electronic effects or steric hindrance (G-C6H4NH2, G = p-NO2,p-CN, o-CO2CH3 and 2,6-dimethylaniline); typical selectivities for the formation of the corresponding mono-N-methyl derivatives [ArNH(CH3)] are in the range 92-98%, at a substrate conversion of 72-93%. A synergic effect between the reactivity of DMC (acting both as a methylating and as a reversible methoxycarbonylating agent) and the dual acid-base properties of zeolites is considered to be responsible for the unusually high selectivity observed; accordingly, a reaction mechanism is discussed, involving carbamates (ArNHCO2CH3) and N-methyl-carbamates [ArN(CH3)CO2CH3] as intermediates. The reaction is an example of a synthesis with low environmental impact: it couples the use of a non-toxic methylating agent (DMC, in place of the highly toxic methyl halides or dimethyl sulfate) with eco-friendly catalysts (zeolites) in a waste-free process.
- Selva, Maurizio,Bomben, Andrea,Tundo, Pietro
-
p. 1041 - 1045
(2007/10/03)
-
- Antisweet natural products. XII. Structures of sitakisosides XI-XX from Stephanotis lutchuensis Koidz. var. japonica
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From the fresh stem of Stephanotis lutchuensis var. japonica, ten new oleanane-type triterpenoid glycosides, named sitakisosides XI-XX (1-10), were isolated. Their structures were determined on the basis of spectroscopic data and chemical evidence. The results show that all have a 3-O-β-D- xylopyranosyl(1→6)-β-D-glucopyranosyl(1→6)-β-D-glucopyranosyl moiety and the aglycones of sitakisosides XI-XV, XVI and XVII, XVIII and XIX, and XX are sitakisogenin, chichipegenin, marsglobiferin and longispinogenin, respectively, Sitakisosides XI-XIII, XVI and XVIII, having an acyl group, showed antisweet activity.
- Yoshikawa, Kazuko,Mizutani, Aki,Kan, Yukiko,Arihara, Shigenobu
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- Decomposition of 2-dialkylaminobenzoyl azides to yield isocyanates and 1,1 -dialky lindazol-1-ium-3-olates
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Substituted benzoyl azides normally yield the correspondingly substituted isocyanates but when a dialkylated amino group is in the 2-position, in addition to the isocyanate, the 1,1-dialkylated indazol-1-ium-3-olate is produced. The ratio of the two products is very variable depending upon the substitution in the benzene ring. Largest yields of the zwitterionic products were found when there was a substituent in the 3-position regardless of whether the substituent was electron-donating or -withdrawing.
- Waldron, Norman M.,Raza, Muhammad
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p. 271 - 276
(2007/10/03)
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- Antisweet natural products. X. Structures of sitakisosides I-V from Stephanotis lutchuensis Koidz. var. japonica
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From the fresh stem of Stephanotis lutchuensis var. japonica, we have isolated five new oleane glycosides named sitakisosides I-V (1-5). Their structures were determined on the basis of spectroscopic data and chemical evidence. Sitakisoside V showed the strongest antisweet activity among sitakisosides I-V.
- Yoshikawa,Taninaka,Kan,Arihara
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p. 2023 - 2027
(2007/10/02)
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- Antisweet natural products. XI. Structures of sitakisosides VI-X from Stephanotis lutchuensis Koidz. var. japonica
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From the fresh stem of Stephanotis lutchuensis var. japonica, five new oleanane-type triterpenoid glycosides named sitakisosides VI-X (1-5) were isolated. Their structures were determined on the basis of spectroscopic data and chemical evidence. Sitakisosides VI and VII are 3-O-β-D-xylopyranosyl(1 → 6)-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranosido-21-O-(6-N-methylanthranilyl)-β-D-glucopyranos yl and 3-O-β-D-xylopyranosyl(1 → 6)-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranosido-21-O-(4-N-methylanthranilyl)-β-D-glucopyranos yl sitakisogenin, respectively. Sitakisoside VIII is 3-O-β-D-xylopyranosyl(1 → 6)-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranosido-21-O-N-methylanthranilyl-3β,16β,21β,28-tetr ahydroxyolean-12-ene-22-one. Sitakisoside IX is 3-O-β-D-xylopyranosyl(1 → 6)-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranosido-21-O-(6-N-methylanthranilyl)-β-D-glucopyranos yl gymnestrogenin. Sitakisoside X is 3-O-β-D-xylopyranosyl(1 → 6)-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranosyl longispinogenin.
- Yoshikawa,Taninaka,Kan,Arihara
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p. 2455 - 2460
(2007/10/02)
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- A facile synthesis of 2-phosphoryl-substituted 3-hydroxyindole derivatives
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A variety of 1-substituted 2-diphenylphosphinoyl-3-hydroxy-1H-indoles 5 a-d and 2-dimethoxyphosphoryl-3-hydroxy-1H-indoles 6a,c have been efficiently prepared by base-induced intramolecular cyclization of the appropriate Horner-Wittig and Wadsworth-Emmons reagents, 2-[(diphenylphosphinoyl)methylamino]-N,N-diethylbenzamides 3a-d and 2-[(dimethoxyphosphoryl)methylamino]-N,N-diethylbenzamides 4a,c, respectively.
- Couture,Deniau,Grandclaudon
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p. 1276 - 1279
(2007/10/02)
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- KINETICS AND MECHANISM OF SOLVOLYSIS OF N-ARYL SULFURIC DIAMIDES
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The methanolysis and hydrolysis kinetics have been studied with the following sulfuric diamide derivatives: N-methyl-N-phenyl- (IIIa), N-methyl-N-(4-methoxycarbonylphenyl)- (IIIb), N-(4-methoxycarbonylphenyl)- (IIIc), N-methyl-N-(2-methoxycarbonylphenyl)- (IIId), N-(2-methoxycarbonylphenyl)- (IIIe), and N-methyl-N-(2,4-dibromophenyl)- (IIIf).The solvolyses of the neutral substrates IIIa and IIIb proceed by the addition-elimination mechanism.In the presence of the solvent lyate ions the solvolyses go by the E1cb mechanism.The solvolyses of the conjugated bases ofcompounds IIIa and IIIb are subject to general acid catalysis, the effects of the ring substituents being opposite to those in the addition-elimination mechanism.The solvolyses of compounds IIId and IIIf exhibit a distinct catalytic effect of neighbouring group; the reaction goes via a reactive intermediate, the transformation of the intermediate into the solvolysis product being subject to general acid and base catalysis.
- Kavalek, Jaromir,Kralikova, Ulrika,Machacek, Vladimir,Sedlak, Milos,Sterba, Vojeslav
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p. 202 - 222
(2007/10/02)
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- A SYNTHETIC EQUIVALENT FOR ORTHO-LITHIO-N-METHYLANILINE
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o-Bromo-N-methyl-N-n-propoxyaniline undergoes halogen-metal exchange with butyllithium and the resulting lithio species reacts cleanly with a variety of electrophiles.The N-O bond of these products can be reduced with Raney nickel to afford ortho-substituted-N-methylanilines.
- Sisko, Joseph,Weinreb, Steven M.
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p. 1035 - 1042
(2007/10/02)
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- The Isolation of Avenacins A-1, A-2, B-1, and B-2, Chemical Defences Against Cereal 'Take-All' Disease. Structure of Their 'Aglycones', the Avenestergenins, and their Anhydro dimers
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The isolation is described of the four pre-formed antifungal compounds, the avenacins, from oat roots.These prevent attack by the wheat pathogen Gaeumannomyces graminis var. tritici (Ggt): the latter is the causative fungus of 'take-all' disease.The four avenacins A-1, A-2, B-1, and B-2 have the same trisaccharide attachment and on deglycosation give as 'aglycones' avenestergenins A-1, A-2, B-1, and B-2.A-1 and B-1 contain an esterifying N-methylanthranilate, A-2 and B-2 a benzoate.All four contain a triterpene core, the A-series being related to the B- by possession of an extra 23-hydroxy group.The structure of avenestergenin A-1 is examined in detail using 1H n.m.r. with spin decoupling and Cosy plot, n.O.e. difference spectroscopy and 2D linkage of 13C and 1H resonances.This and mass spectral work, leads to complete structural and stereochemical proposals for the avenestergenins.After considerable difficulties, an X-ray structure of avenestergenin A-2 has been achieved.The four avenestergenins form a set of eight anhydro dimers, investigated by n.m.r. and f.a.b. mass spectra.These result from formation of 1,3-dioxane rings using the C-3 and C-23 hydroxy groups of one molecule of the A-series with the C-30 aldehyde of another molecule of either the A or the B series.
- Begley, Michael J.,Crombie, Leslie,Crombie, W. Mary L.,Whiting, Donald A.
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p. 1905 - 1916
(2007/10/02)
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- Process for the preparation of methyl N-methylanthranilate
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A mixture of methyl anthranilate, dissolved in a water-miscible solvent, with a solution of formaldehyde is reduced in a hydrogen atmosphere in the presence of a hyrogenation catalyst at moderate temperatures and pressures to yield methyl N-methylanthranilate. The invention provides a process which is feasible towards producing the compound in commercial quantities in high purity and good yield.
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- Synthesis of methyl N-methylanthranilate
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Methyl N-methylanthranilate is prepared by reductive alkylation of methylanthranilate with formaldehyde and hydrogen in the presence of a hydrogenation catalyst and an acid catalyst.
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- Reactions of Anthranilium Salts with Nucleophiles: Adduct Formation and Rearrangement
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3-Unsubstituted anthranilium salts 1 react with alcohols in the presence of bases to yield adducts 5 which rearrange to the esters 4 when refluxed in xylene.Similar processes involving 1 and cyanide or azide also have been observed.Evidence favoring benzoazetinones 2 as rearrangement intermediates is presented.The chemistry of 1 with phosphines and phosphites is also described.For example, treatment of 1c with trimethyl phosphite yields the rearranged adduct salt 14 which cleaves to the acyl phosphonate 15 when treated with triethylamine.
- Vander Meer, Robert K.,Olofson, R. A.
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p. 3373 - 3377
(2007/10/02)
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- Studies on Lactam Acetals: Part V - Use in N-, O- and S-Alkylations and Esterification
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The utility of 2,2-dimethoxy-1-methylpyrrolidine as a reagent for facile N-, O-, S-alkylations and esterification, or both simultaneously, of a wide variety of substrates has been demonstrated.
- Singh, Jujhar,Nigam, M. B.,Sardana, Vinod,Jain, Padam C.,Anand, Nitya
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p. 596 - 597
(2007/10/02)
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- A Novel Oxamide Rearrangement
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An efficient, base-induced rearrangement of 2-benzoic acid methyl ester (7a) to the isomeric 2-benzoic acid methyl ester (27a) is described.This novel rearrangement must proceed through a spiro intermediate wherein benzoate is acting as a Michael receptor.When 2-benzoic acid methyl ester (28) - an oxamide which would produce a degenerate spiro intermediate - was subjected to rearrangement conditions, the product obtained was 1,3-dimethyl-2,4-(1H,3H)quinazolinedione (29).This latter transformation may have proceeded via a benzodiazepinetrione intermediate.
- Peet, Norton P.,Sunder, Shyam,Barbuch, Robert J.
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p. 1513 - 1518
(2007/10/02)
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