- A Synthetic Strategy for Saxitoxin Skeleton by a Cascade Bromocyclization: Total Synthesis of (+)-Decarbamoyl-α-saxitoxinol
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A new synthetic strategy for the formation of the ABC tricyclic framework of saxitoxin was developed. The BC ring moiety, including a spiro-aminal structure, was first constructed stereoselectively by a newly designed cascade bromocyclization of a readily available internal alkyne bearing guanidine and urea. The A ring was then synthesized by a guanylation of a cyclic urea, easily prepared via the oxidative cleavage of the diol of the cascade product, followed by addition of cyanide. This strategy enables the concise stereocontrolled total synthesis of (+)-decarbamoyl-α-saxitoxinol, which is a naturally occurring saxitoxin analogue.
- Ueno, Sohei,Nakazaki, Atsuo,Nishikawa, Toshio
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Read Online
- Design, synthesis and anticancer activity of a new series of n-aryl-n′-[4-(Pyridin-2-ylmethoxy)benzyl]urea derivatives
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The development of cancer treatments requires continuous exploration and improvement, in which the discovery of new drugs for the treatment of cancer is still an important pathway. In this study, based on the molecular hybridization strategy, a new structural framework with an N-aryl-N’-arylmethylurea scaffold was designed, and 16 new target compounds were synthesized and evaluated for their antiproliferative activities against four different cancer cell lines A549, MCF7, HCT116, PC3, and human liver normal cell line HL7702. The results have shown seven compounds with 1-methylpiperidin-4-yl groups having excellent activities against all four cancer cell lines, and they exhibited scarcely any activities against HL7702. Among them, compound 9b and 9d showed greatly excellent activity against the four kinds of cells, and the IC50 for MCF7 and PC3 cell lines were even less than 3μM.
- Hou, Shicheng,Liang, Shishao,Zhang, Chao,Han, Yingmei,Liang, Jianhui,Hu, Hongyu,Zhang, Xingeng,Hu, Chun,Liu, Xiaoping,Zhang, Hong
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- NOVEL CYCLICSULFONIMIDOYLPURINONE COMPOUNDS AND DERIVATIVES FOR THE TREATMENT AND PROPHYLAXIS OF VIRUS INFECTION
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The present invention relates to compounds of formula (I), wherein R1, R2 and R3 and n are as described herein, or pharmaceutically acceptable salt, enantiomer or diastereomer thereof, and compositions including the compounds and methods of using the compounds.
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Page/Page column 19; 26
(2018/05/24)
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- Amide compound, pharmaceutical composition, preparation method and application thereof
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The invention provides an amide compound, a pharmaceutical composition, a preparation method and application thereof and belongs to the field of medicine. Structure of the amide compound is shown as aformula I. The preparation method includes: in an alkaline condition and in an organic solvent, allowing a compound I and a compound II to be in condensation reaction. The amide compound or pharmaceutically acceptable salt thereof have long-acting sensory and/or motion blocking activity, can be used for preparing long-acting local anesthetic or analgesic and is long in efficacy lasting time, little side effect and high in medication safety.
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Paragraph 0196-0199
(2018/09/11)
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- BICYCLIC PESTICIDAL COMPOUNDS
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The present invention relates to compounds of formula (I), wherein the variables are defined as given in the description and claims. The invention further relates to uses, processes and composition for compounds (I).
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Page/Page column 65
(2018/12/13)
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- Design and Synthesis of 4-Alkylidene-β-lactams: Benzyl- and Phenethyl-carbamates as Key Fragments to Switch on Antibacterial Activity
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The emergence of multidrug-resistant bacterial strains is particularly important in chronic pathologies such as cystic fibrosis (CF), in which persistent colonization and selection of resistant strains is favored by the frequent and repeated use of antibacterial agents. Staphylococcus aureus is a common pathogen in CF patients that has an associated increased multidrug resistance. In previous studies we demonstrated that the presence of a 4-alkylidene side chain directly linked to a β-lactam appeared to strengthen the potency against S. aureus, especially against methicillin-resistant S. aureus (MRSA) strains. In the present study, 21 new 4-alkylidene-β-lactams were synthesized and evaluated for antibacterial activity. We designed the new compounds to have aryl, benzyl, or phenethyl-carbamate groups on the C3 hydroxyethyl side chain. We found a correlation between biological activity and the nitrogen substituent of the carbamate group, and two phenethyl-carbamate β-lactams were shown to be valuable antibacterial agents against selected linezolid-resistant strains, with a minimum inhibitory concentrations of 2–4 mg L?1.
- Giacomini, Daria,Martelli, Giulia,Piccichè, Miriam,Calaresu, Enrico,Cocuzza, Clementina Elvezia,Musumeci, Rosario
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p. 1525 - 1533
(2017/09/25)
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- BICYCLIC COMPOUNDS
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The present invention relates to compounds of formula (I), wherein the variables are defined as given in the description and claims. The invention further relates to uses, processes and composition for compounds I.
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Page/Page column 67
(2017/10/31)
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- Enantioselective synthesis of 3,5-disubstituted thiohydantoins and hydantoins
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A mild method to convert optically pure amino acid thiourea and urea derivatives to thiohydantoins and hydantoins, respectively, is described. It provides an efficient way to realize enantioselective synthesis of thiohydantoins and hydantoins with good to high isolated yields and enantiomeric purities. We found that the enantiomeric purities were highly dependent on the reaction conditions including bases, solvents, and temperature.
- Chen, Yu,Su, Li,Yang, Xinying,Pan, Wenyan,Fang, Hao
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p. 9234 - 9239
(2015/11/27)
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- Design, synthesis and evaluation of 1,2-benzisothiazol-3-one derivatives as potent caspase-3 inhibitors
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A number of 1,2-benzisothiazol-3-one derivatives were prepared through structural modification of the original compound from high-throughput screening. Some analogues (e.g., 6b, 6r, 6s and 6w) were identified as novel and potent caspase inhibitors with IC50 of nanomolar. Structure-activity relationship (SAR) studies for caspase-3 inhibition were evaluated in vitro. Molecular modeling studies provided further insight into the interaction of this class of compounds with activated caspase-3. The present small molecule caspase-3 inhibitor with novel structures different from structures of known caspase inhibitors revealed a new direction for therapeutic strategies directed against diseases involving abnormally up-regulated apoptosis.
- Liu, Dazhi,Tian, Zhen,Yan, Zhihui,Wu, Lixin,Ma, Yan,Wang, Quan,Liu, Wei,Zhou, Honggang,Yang, Cheng
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p. 2960 - 2967
(2013/07/28)
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- Design, synthesis, and evaluation of pH-dependent hydrolyzable emetine analogues as treatment for prostate cancer
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The N-2′ position of the natural product emetine has been derivatized to thiourea, urea, sulfonamide, dithiocarbamate, carbamate, and pH responsive hydrolyzable amide analogues. In vitro studies of these analogues in PC3 and LNCaP prostate cancer cell lines showed that the analogues are generally less cytotoxic (average IC50 ranging from 0.079 to 10 μM) than emetine (IC50 ranging from 0.0237 to 0.0329 μM). The pH sensitive sodium dithiocarbamate salt 13 and the amide analogues 21, 22, 26 (obtained from maleic and citraconic anhydrides) showed the most promise as acid-activatable prodrugs under mildly acidic conditions found in the cancer microenvironment. These prodrugs released 12-83% of emetine at pH 6.5 and 41-95% emetine at pH 5.5. Compounds 13 and 26 were further shown to exhibit increased cytotoxicity in PC3 cell culture medium that was already below pH 7.0 at the time of treatment.
- Akinboye, Emmanuel S.,Rosen, Marc D.,Denmeade, Samuel R.,Kwabi-Addo, Bernard,Bakare, Oladapo
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supporting information
p. 7450 - 7459
(2012/10/29)
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- (Tosylimino)phenyl-λ3-iodane as a reagent for the synthesis of methyl carbamates via hofmann rearrangement of aromatic and aliphatic carboxamides
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A new, mild procedure for the Hofmann rearrangement of aromatic and aliphatic carboxamides using (tosylimino)phenyl-λ3-iodane, PhINTs, as a reagent is reported. Because of the mild reaction conditions, this method is particularly useful for the Hofmann rearrangement of substituted benzamides, which usually afford complex reaction mixtures with other hypervalent iodine oxidants. The mild reaction conditions and high selectivity in the reaction of carboxamides with PhINTs allow the isolation of the initially formed labile isocyanates or their subsequent conversion to stable carbamates by treatment with alcohols.
- Yoshimura, Akira,Luedtke, Matthew W.,Zhdankin, Viktor V.
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experimental part
p. 2087 - 2091
(2012/05/05)
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- Development of synthetic aminopeptidase N/CD13 inhibitors to overcome cancer metastasis and angiogenesis
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Cancer metastasis is a major barrier to its treatment and an important cause of patient death. Antimetastatic agents hold promise for patients with advanced metastatic tumors. Aminopeptidase N/CD13 (APN) is being pursued by many as an important target against cancer metastasis and angiogenesis, but there are few reports on the in vivo evaluation of synthetic APN inhibitors. Herein, a series of compounds targeting APN were synthesized and evaluated for their antimetastasis and antiangiogenesis potency both in vitro and in vivo. Excitingly, compounds 4m, 4t, and 4cc, with the most potent APN inhibitory activities, displayed significant antimetastasis and antiangiogenesis effects in vitro and in vivo, suggesting that those synthetic APN inhibitors have the potential to overcome cancer metastasis and angiogenesis.
- Su, Li,Cao, Jiangying,Jia, Yuping,Zhang, Xiaonan,Fang, Hao,Xu, Wenfang
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supporting information
p. 959 - 964
(2013/02/23)
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- Synthesis and biological evaluation of glycogen synthase kinase 3 (GSK-3) inhibitors: An fast and atom efficient access to 1-aryl-3-benzylureas
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The glycogen synthase kinase 3 (GSK-3) is implicated in multiple cellular processes and has been linked to the pathogenesis of Alzheimer's disease (AD). In the course of our research topic we synthesized a library of potent GSK-3 inhibitors. We utilized the urea scaffold present in the potent and highly selective GSK-3 inhibitor AR-A014418 (AstraZeneca). This moiety suits both (a) a convergent approach utilizing readily accessible building blocks and (b) a divergent approach based on a microwave heating assisted Suzuki coupling. We established a chromatography-free purification method to generate products with sufficient purity for the biological assays. The structure-activity relationship of the library provided the rationale for the synthesis of the benzothiazolylurea 66 (IC50 = 140 nM) and the pyridylurea 62 (IC 50 = 98 nM), which displayed two to threefold enhanced activity versus the reference compound 18 (AR-A014418: IC50 = 330 nM) in our assays.
- Monte, Fabio Lo,Kramer, Thomas,Bol?nder, Alexander,Plotkin, Batya,Eldar-Finkelman, Hagit,Fuertes, Ana,Dominguez, Juan,Schmidt, Boris
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supporting information; experimental part
p. 5610 - 5615
(2011/10/09)
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- Triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone (DDQ)/[n-Bu4N]OCN as a useful system for the efficient conversion of tetrahydropyranyl (THP) ethers to the corresponding alkyl isocyanates
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Triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone/tetrabutylammonium cyanate was used as an efficient system for the conversion of tetrahydropyranyl ethers to the corresponding alkyl isocyanates. Taylor & Francis Group, LLC.
- Akhlaghinia, Batool,Samiei, Sima
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experimental part
p. 2525 - 2529
(2010/03/31)
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- Regioselective rhodium-catalyzed intermolecular [2+2+2] cycloaddition of alkynes and isocyanates to form pyridones
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A highly regioselective rhodium-catalyzed intermolecular [2+2+2] cycloaddition of terminal alkynes with a variety of isocyanates to provide 2- and 4-pyridones has been developed. This reaction proceeds in good to excellent yields and overcomes the problem of dimerization and trimerization through the use of phosphoramidite ligands. A CO migration in the metallacycle is proposed to account for the formation of 4-pyridone.
- Oberg, Kevin M.,Lee, Ernest E.,Rovis, Tomislav
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experimental part
p. 5056 - 5061
(2009/10/24)
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- FUSED PYRIMIDINE DERIVATIVE
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The present invention provides a fused pyrimidine derivative having an insulin secretion stimulating activity represented by Formula (I): {wherein R1 represents a hydrogen atom, lower alkyl, or the like; n represents an integer of 0 to 3; and X1 and X2 may be the same or different and each represents a hydrogen atom, lower alkyl, or the like; and formula (II): represents formula (III): [wherein X--Y--Z represents R2C=CR3-NR4 (wherein R2, R3 and R4 may be the same or different and each represents a hydrogen atom, lower alkyl, or the like)]}, or a pharmaceutically acceptable salt thereof.
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Page/Page column 14
(2010/11/08)
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- Organosilicon synthesis of isocyanates: II. Synthesis of aliphatic, carbocyclic, and fatty-aromatic isocyanates
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Silylation of a series of aliphatic, carbocyclic, and fatty-aromatic amines gave the corresponding silyl derivatives whose yield depended on the electronic and steric structure of the substrate and the nature of the silylating agent. The yield of isocyanates obtained by phosgenation of the silyl derivatives under mild conditions decreased in going from aliphatic amines to benzylamines and rose as the length of the alkyl chain in fatty-aromatic amines extended. The most convenient procedure for the synthesis of low-boiling alkyl isocyanates was found to be based on the transformation of amines or ammonium salts into silyl or silyl silyl-carabamates, followed by pyrolysis of the latter in the presence of trichloro(phenyl)silane. Pleiades Publishing, Inc., 2006.
- Lebedev,Lebedeva,Sheludyakov,Ovcharuk,Kovaleva,Ustinova
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p. 469 - 477
(2008/02/07)
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- A new and convenient method of generating alkyl isocyanates from alcohols, thiols and trimethylsilyl ethers using triphenylphosphine/2,3-dichloro-5,6- dicyanobenzoquinone/Bu4NOCN
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Alkyl isocyanates are prepared in good to excellent yields by treatment of alcohols, thiols and trimethylsilyl ethers with triphenylphosphine/2,3-dichloro- 5,6-dicyanobenzoquinone/ Bu4NOCN in acetonitrile. This method is highly selective for conversion of primary alcohols to alkyl isocyanates in the presence of secondary and tertiary alcohols, thiols and trimethysilyl ethers. Georg Thieme Verlag Stuttgart.
- Akhlaghinia, Batool
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p. 1955 - 1958
(2007/10/03)
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- Manipulation of N,O-nucleophilicity: Efficient formation of 4-N-substituted 2,4-dihydro-3H-1,2,4-triazolin-3-ones
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(Chemical Equation Presented) A new efficient two-step synthesis of 2,4-dihydro-3H-1,2,4-triazolin-3-ones (triazolinones) from readily available amines is reported. Our novel conditions using hexamethyl disilazane, bromotrimethylsilane, and a catalytic amount of ammonium sulfate smoothly cyclize 1-formyl and 1-acetyl semicarbazides to the target triazolinones. This transformation features simultaneous manipulation of N- and O-nucleophilicity as well as differentiation of the nucleophilicity of a urea and an acyl carbonyl.
- Huang, Xianhai,Palani, Anandan,Xiao, Dong,Aslanian, Robert,Shih, Neng-Yang
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p. 4795 - 4798
(2007/10/03)
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- Efficient synthesis of 2,9-disubstituted 8-hydroxyadenine derivatives
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An efficient and general method for the synthesis of 2,9-disubstituted 8-hydroxyadenines, which are expected to have various biological activities, was realized. 5-amino-4-cyano-2-hydroxyimidazoles(1) were prepared from aminomalononitrile and isocyanates as key intermediates. The condensation of 1a with amidines, imidates, guanidine, urea and thioureas afforded 8-hydroxyadenines (2-6) possessing various substituents at the 2-position. Furthermore, selective alkylation of 2-amino- and 2-hydroxyadenines (4 and 6) successively proceeded to give the corresponding 2-alkylamino- and 2-alkoxyadenines (5 and 7), respectively. 2-Alkythioadenines (15) were prepared by an analogous reaction of 1a with benzoyl isothiocyanate and subsequent S-alkylation. The imidazoles 1 are most useful intermediated for the synthesis of 8-hydroxyadenine derivatives.
- Hirota, Kosaku,Kazaoka, Kazunori,Niimoto, Itaru,Sajiki, Hironao
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p. 1354 - 1365
(2007/10/03)
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- Synthesis, selective aldose reductase inhibitory profile and antihyperglycaemic potential of certain parabanic acid derivatives
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Synthesis and aldose reductase inhibitory profile of certain parabanic acid derivatives 1a-p is described. Also, the antihyperglycaemic potential of these compounds was studied. The most active inhibitors in this series were compounds 1 g, 1p, and 1o which showed inhibitory activity, 36.6, 90 and 91% respectively, at concentration 1 × 10-4. Their IC50 were 2 × 10-6, 7.5 × 10-8 and 5 × 10-8, respectively. Compound 1o exhibited pronounced antihyperglycaemic effect.
- Nabil Aboul-Enein,El-Azzounya,Maklad,Attia,Wiese
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p. 329 - 350
(2007/10/03)
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- Inhibition of serine proteases: Activity of 1,3-diazetidine-2,4-diones
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The present work demonstrates that the 1,3-diazetidine-2,4-dione nucleus is effective as a scaffold of serine protease inhibitors. Compound 1 displayed high activity against human cathepsin G and α-chymotrypsin (0.39, 0.69 nM). Compound 6 exhibited 0.85 nM inhibition of human chymase. Compound 10 was a selective inhibitor against human neutrophil elastase.
- Aoyama, Yasunori,Uenaka, Masaaki,Konoike, Toshiro,Hayasaki-Kajiwara, Yoko,Naya, Noriyuki,Nakajima, Masatoshi
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p. 1691 - 1694
(2007/10/03)
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- Reactions of Charged Substrates. 8. The Nucleophilic Substitution Reactions of (4-Methoxybenzyl)dimethylsulfonium Chloride
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Displacement reactions on the title compound (1) occur only for nucleophiles with intermediate hardness. Nucleophiles that react display a range of mechanisms. 1 reacts with the neutral nucleophile pyridine-d5 through a mixed SN1/SN2 mechanism; salt added to control ionic strength affects the rate for the unimolecular process, but has no effect on the bimolecular rate constant. The mechanism of displacement by N3- and SO32- depends on the presence or absence of exogenous salt. At constant ionic strength, the mechanism is mixed SN1/SN2 over most of the range of [Nu]. With nucleophile only present, plots of kobsd vs [Nu] exhibit severe breaks that are not the result of salt effects. Analysis of rate constants and product ratios suggests that at low [Nu] reaction occurs simultaneously through concerted Hughes-Ingold SN2 and preassociation-concerted mechanisms. At high [Nu], displacement occurs only through the preassociation-concerted mechanism. Comparison of these results with data for gas-phase dissociation of benzyl dimethylsulfoniums and with solution results for benzyl pyridiniums suggests that the intrinsic stability of the intermediate does not necessarily determine the mechanism.
- Buckley, Neu,Oppenheimer, Norman J.
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p. 540 - 551
(2007/10/03)
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- Antitumour imidazotetrazines. Part 33. New synthesis of the antitumour drug temozolomide using 'masked' methyl isocyanates
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Ethyl 8-carbamoyl-4-oxo-3,4-dihydroimidazo-1,2,3,5-tetrazin-3-ylacetate 6a can be prepared by treating 5-diazoimidazole-4-carboxamide 3 with ethyl isocyanatoacetate or by diazotisation of N-(5-amino-4-carbamoylimidazol-1-ylcarbonyl)glycine ethyl ester 5.Barton radical decarboxylation of the tetrazin-3-ylacetic acid 6b affords temozolomide 1 (26percent) whereas deprotection of the 3-trimethylsilylmethylimidazotetrazine 6g with TBAF in acetonitrile-acetic acid yields 1 in 78percent yield. 3-Benzylimidazotetrazinones 10a-c are stable to hydrogenolytic or oxidative debenzylation reactions.
- Wang, Yongfeng,Stevens, Malcolm F. G.,Thomson, William T.,Shutts, Bruce P.
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p. 2783 - 2789
(2007/10/02)
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- Stereoselectivity synthesis of (+)-hydantocidin
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The naturally occurring spironuceleoside (+)-hydantocidin 1 was synthesized from 1,2:3,4-di-O-isopropylidene-D-psicofuranose using a new oxygen-bridged intramolecular Vorbruggen coupling of the N-hydroxyurea 5 in presence of a catalytic amount of trimethylsilytriflate.
- Chemla
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p. 7391 - 7394
(2007/10/02)
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- Orally Active β-Lactam Inhibitors of Leukocyte Elastase-1. Activity of 3,3-Diethyl-2-azetidinones
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A thorough analysis of the mechanism of inhibition of human leukocyte elastase (HLE) by a monocyclic β-lactam and the mechanism of β-lactam hydrolysis led to the preparation of potent and highly stable inhibitors of HLE.This work led to the identification of 4--3,3-diethyl-1-carbonyl>-2-azetidinone (2) as the first orally active inhibitor of human leukocyte elastase (HLE).Analogs of 2 with different substituents on the urea N were synthesized and evaluated for their activity in vitro against HLE as well as in vivo in a hamster lung hemorrhage model.Compounds with a methyl or a methoxy group in the para position of the benzene ring were very potent in both assays.The results are discussed on the basis of the proposed model for the binding of this class of inhibitors to HLE and a possible mechanism of inhibition is presented.
- Shah, Shrenik K.,Dorn, Conrad P.,Finke, Paul E.,Hale, Jeffrey J.,Hagmann, William K.,et al.
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p. 3745 - 3754
(2007/10/02)
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