- Synthesis and antibacterial activities of Yanglingmycin analogues
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The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62 μg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.
- Li, Long-Bo,Dan, Wen-Jia,Tan, Fang-Fang,Cui, Li-Hui,Yuan, Zhi-Peng,Wu, Wen-Jun,Zhang, Ji-Wen
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- Transition-metal-free approach to 4-ethynylpyrimidines via alkenynones
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A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4- yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%. Copyright
- Golubev, Pavel R.,Pankova, Alena S.,Kuznetsov, Mikhail A.
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p. 3614 - 3621
(2014/06/23)
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- A flexible Pinner preparation of orthoesters: The model case of trimethylorthobenzoate
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In the absence of additional solvents, a novel procedure was implemented for the synthesis of trimethylorthoesters through the Pinner reaction. At 5 °C, the reaction of both aliphatic and aromatic nitriles (RCN; R = Et, Bu, Ph) with a moderate excess of MeOH and gaseous HCl gave the corresponding imidate hydrochlorides [RC(NH)OR′·HCl] in excellent yields (>90%). At 25-65 °C, the methanolysis of alkyl imidate salts provided trimethylortho-propionate and valerate, while only traces of trimethylorthobenzoate (TMOB) were observed. However, the aromatic hydrochloride could be readily converted into the hydrogenphosphate salt [PhC(NH) OR′·H3PO4] which, in turn, underwent a selective (>80%) reaction with MeOH to produce TMOB in a 62% isolated yield. This allowed for an unprecedented Pinner-type synthesis of TMOB starting from benzonitrile, rather than from the highly toxic trichloromethylbenzene. Overall, remarkable improvements in safety and process intensification were achieved.
- Noe, Marco,Perosa, Alvise,Selva, Maurizio
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p. 2252 - 2260
(2013/09/24)
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- Synthesis and evaluation of adenosine antagonist activity of a series of [1,2,4]triazolo[1,5-c]quinazolines
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A series of [1,2,4]triazolo[1,5-c]quinazolines were prepared in satisfactory yields by reaction of some derivatives of 2-aminobenzohydrazide with several hydrochlorides of aromatic amidines, and their binding affinities for the recombinant human adenosine A2A and A2B receptors were determined. None of the new compounds showed noteworthy affinity for these receptors, though a very high affinity for the A2A receptor and, consequently, a high level of A2A/A2B selectivity was revealed for one of the synthesized compounds.
- Balo, Carmen,Lopez, Carmen,Brea, Jose Manuel,Fernandez, Franco,Caamano, Olga
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p. 372 - 375
(2008/02/02)
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- FUNGICIDAL HETEROCYCLIC COMPOUNDS
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A compound which can specifically or selectively expresses an antifungal activity with a broad spectrum, based on the functional mechanism of 1,6-β-glucan synthesis inhibition, is provided, and an antifungal agent which comprises such a compound, a salt thereof or a solvate thereof is provided. A compound represented by the following formula (I), a salt thereof or a solvate thereof.
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Page/Page column 55
(2010/11/24)
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- Preparation and resolution of a modular class of axially chiral quinazoline-containing ligands and their application in asymmetric rhodium-catalyzed olefin hydroboration
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The preparation and resolution of a series of axially chiral quinazoline-containing ligands is described in which the key steps are the metal-catalyzed naphthyl-phosphorus bond formation, the naphthalene-quinazoline Suzuki coupling, and the preparation of the Suzuki electrophilic components from the corresponding imidate and anthranilic acid. Diastereomeric palladacycles derived from the racemic phosphinamines and (+)-di-μ-chlorobis[(R)- dimethyl(1-(1-naphthyl)ethyl)-aminato-C2,N]dipalladium(II) were separated by fractional crystallization. The configuration of the resulting diastereomers was determined by X-ray crystallographic analysis. Displacement of the resolving agent by reaction with 1,2-bis(diphenylphosphino)ethane afforded enantiopure ligand in each case. Their rhodium complexes were prepared and applied in the enantioselective hydroboration of a range of vinylarenes. The quinazolinap catalysts were found to be extremely active, giving excellent conversions, good to complete regioselectivities, and the highest enantioselectivities obtained to date for several members of the vinylarene class, including cis-β-methylstyrene (97%), cis-stilbene (99%), and indene (99.5%).
- Connolly, David J.,Lacey, Patrick M.,McCarthy, Mary,Saunders, Cormac P.,Carroll, Anne-Marie,Goddard, Richard,Guiry, Patrick J.
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p. 6572 - 6589
(2007/10/03)
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- A facile and versatile route to 2-substituted-4(3H)-quinazolinones and quinazolines
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A range of 2-aryl and 2-alkyl quinazolinones have been prepared in moderate to good yields from the reaction of anthranilic acid and the appropriately substituted imidate in a facile, mild, onepot procedure. Subsequent reaction with phosphorus oxychloride afforded the corresponding 4-chloro-2-substituted quinazolines, which are useful synthetic intermediates, in good to high yields. Product isolation was facilitated by the development of work up procedures for both reactions that did not include purification by column chromatography.
- Connolly,Guiry
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p. 1707 - 1710
(2007/10/03)
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- Iminium Carbonic Acid Derivative Salts. XI [1]. Synthesis of N,S-Containing Heterobicycles from N-Protected 2-Methylthio-1,3-thiazinium and 2-Methylthiothiazolium Salts. Part 3. Reaction of N-Protected 2-Methylthio-1,3-thiazinium and 2-Methylthiothiazolium Salts with 3-Amino-2-cyano-3-arylacrylonitriles
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N-Boc-protected 2-methylthio-1,3-thiazinium 1 and 2-methylthiothiazolium iodides 2,3 obtained from the corresponding 3,4,5,6-tetrahydro-2H-1,3-thiazine-2-thiones and thiazolidine-2-thiones by the action of methyl iodide were reacted with 3-amino-2-cyano-3-arylacrylonitriles forming the cyclic isothioureas 5-7. The protection group was removed with trifluoroacetic acid whereupon the desired cyclisation to 3,4-dihydro-2H,6H-pyrimido[2,1-b][1,3]thiazines 8a-c, 8a′-c′ and thiazolo[3,2-b]pyrimidines 9a,b, 9a′,b′, 10a,b took place.
- Hanefeld, Wolfgang,Naeeni, Mahmoud,Schlitzer, Martin
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p. 1903 - 1907
(2007/10/03)
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- Synthesis and structural, conformational, biochemical, and pharmacological study of new compounds derived from tropane-3-spiro-4'(5')-imidazoline as potential 5-HT3 receptor antagonists
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A series of tropane-3-spiro-4'(5')-imidazolines was synthesized and studied by 1H and 13C NMR spectroscopy, and the crystal structure of 2'- (1H-indol-3-yl)tropane-3-spiro-4'(5')-imidazoline hydrochloride 5(6)f was determined by X-ray diffraction. In CD3OD solution, compounds 5(6)a-f display the same preferred conformation. The pyrrolidine and piperidine rings adopt an envelope conformation flattened at N8 and a distorted chair conformation puckered at N8 and flattened at C3, respectively, with the N- substituent in the equatorial position with respect to the piperidine ring. This conformation is similar to that observed for compound 5(6)f in the solid state. From binding studies on the compounds synthesized, compound 5(6)d demonstrated the ability to efficiently displace the binding of [3H]GR65630 to bovine brain area postrema membranes to an extent comparable to MDL 72222. In the von Bezold-Jarisch reflex, compound 5(6)d was equipotent with metoclopramide. It is, therefore, likely that the imidazoline ring may provide a useful bioisosteric replacement for the carbonyl group in 5-HT3 antagonists.
- Whelan,Iriepa,Galvez,Orjales,Berisa,Labeaga,Garcia,Uceda,Sanz-Aparicio,Fonseca
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p. 101 - 106
(2007/10/02)
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- Synthesis of 2'-arylazabicyclo-3-spiro-4'(5')-imidazolines
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A method is described for the synthesis of a series of 2'-aryl-3-azabicyclospiro-4'(5')-imidazolines via the reaction of azabicyclic 1,2-diamines with aryl imidate salts. Competing reactions in the synthesis of the diamines such as the reduction of amino nitriles with LiAlH4 lead to some anomalous products. In the Pinner synthesis, unstable pyridine-type imidates were stabilized as their N-oxide derivatives.
- Whelan,Iriepa,Galvez
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p. 832 - 836
(2007/10/02)
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- The reaction of imidates with isocyanates
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Derivatives of isocyanates were prepared by reaction with imidates. Fragmentation reactions and behaviour in a simple biological test were examined.
- Schweim
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p. 319 - 321
(2007/10/02)
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- Synthesis of N-(α-Methoxyalkyl) Amides from Imidates
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Two general routes from imidates to N-(α-methoxyalkyl) amides (e.g.,R'CONHCH(OCH3)R, 1) are reported.The first involves acylation of the imidate on nitrogen with an acyl chloride, followed by reduction with sodium borohydride.In the second, an aldehyde is converted, via its methyl acetal, to an α-chloro methyl ether, which is used to alkylate the imdate.Further treatment with pyridinium chloride in dry Me2SO yields 1.Thirteen examples are reported.
- Lokensgard, Jerrold P.,Fischer, John W.,Bartz, William J.
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p. 5609 - 5611
(2007/10/02)
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- REACTION OF ARYLSELENIUM CHLORIDES WITH N-CHLORO COMPOUNDS
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The reaction of arylselenium chlorides with N-chloro derivatives of morpholine, benzotriazole, succinimide, phthalimide, imidic esters, and ketimines leads to the formation of compouds of tetracoordinated selenium, i.e. arylaminoselenium dichlorides.The same compounds are obtained in the reaction of arylselenium trichlorides with N-trimethylsilylamines of the R2NSiMe3 type.
- Derkach, N.Ya.,Lyapina, T.V.
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p. 448 - 452
(2007/10/02)
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