10072-05-6Relevant articles and documents
Synthesis of xanthones, thioxanthones, and acridones by the coupling of arynes and substituted benzoates
Zhao, Jian,Larock, Richard C.
, p. 583 - 588 (2007)
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.
Mono-N-methylation of functionalized anilines with alkyl methyl carbonates over NaY faujasites. 4. Kinetics and selectivity
Selva, Maurizio,Tundo, Pietro,Foccardi, Tommaso
, p. 2476 - 2485 (2005)
(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.
Identification of a new antinociceptive alkaloid isopropyl N-methylanthranilate from the essential oil of Choisya ternata Kunth
Radulovi?, Niko S.,Miltojevi?, Ana B.,McDermott, Michael,Waldren, Steve,Parnell, John Adrian,Pinheiro, Mariana Martins Gomes,Fernandes, Patricia Dias,De Sousa Menezes, Fabio
, p. 610 - 619 (2011)
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.
Selective N,N-dimethylation of primary aromatic amines with methyl alkyl carbonates in the presence of phosphonium salts
Selva, Maurizio,Perosa, Alvise,Tundo, Pietro,Brunelli, Davide
, p. 5770 - 5773 (2006)
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.
Palladium-Catalyzed Multistep Tandem Carbonylation/N-Dealkylation/Carbonylation Reaction: Access to Isatoic Anhydrides
Wang, Shoucai,Li, Xuan,Zang, Jiawang,Liu, Meichen,Zhang, Siyu,Jiang, Guangbin,Ji, Fanghua
, p. 2672 - 2679 (2020/02/04)
A novel and efficient synthesis of isatoic anhydride derivatives was developed via palladium-catalyzed multistep tandem carbonylation/N-dealkylation/carbonylation reaction with alkyl as the leaving group and tertiary anilines as nitrogen nucleophiles. This approach features good functional group compatibility and readily available starting materials. Furthermore, it provided a convenient approach for the synthesis of biologically and medicinally useful evodiamine.
Novel 1,3- spirocyclization reaction in the photochemistry of anthranilic acid derivatives in acetonitrile
Sharshira, Essam Mohamed
, p. 527 - 534 (2007/10/03)
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
Selective mono-N-methylation of primary aromatic amines by dimethyl carbonate over faujasite X- and Y-type zeolites
Selva, Maurizio,Bomben, Andrea,Tundo, Pietro
, p. 1041 - 1045 (2007/10/03)
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.
Decomposition of 2-dialkylaminobenzoyl azides to yield isocyanates and 1,1 -dialky lindazol-1-ium-3-olates
Waldron, Norman M.,Raza, Muhammad
, p. 271 - 276 (2007/10/03)
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.
2-[(2-Aminobenzyl)sulfinyl]-1-(2-pyridyl)-1,4,5,6- tetrahydrocyclopent[d]imidazoles as a novel class of gastric H+/K+-ATPase inhibitors
Yamada,Yura,Morimoto,Harada,Yamada,Honma,Kinoshita,Sugiura
, p. 596 - 604 (2007/10/03)
Substituted 2-sulfinylimidazoles were synthesized and investigated as potential inhibitors of gastric H+/K+-ATPase. The 4,5-unsubstituted imidazole series 6-11 and the 1,4,5,6-tetrahydrocyclopent[d]imidazole series 12 were found to be potent inhibitors of the acid secretory enzyme H+/K+- ATPase. Structure-activity relationships indicate that the substitution of 2- pyridyl groups at the 1-position of the imidazole moiety combined with (2- aminobenzyl)sulfinyl groups at the 2-position leads to highly active compounds with a favorable chemical stability. Other substitution patterns in the imidazole moiety result in reducing biological activities. 2-[(2- Aminobenzyl)sulfinyl]-1-[2-(3-methylpyridyl)]-1,4,5,6- tetrahydrocyclopent[d]imidazole (12h, T-776) was selected for further development as a potential clinical candidate. Extensive study on the acid degradation of 12h indicates a mechanism of action different from that of omeprazole, the first H+/K+-ATPase inhibitor introduced to the market.
