- Monodentate Transient Directing Group Enabled Pd-Catalyzed Ortho-C-H Methoxylation and Chlorination of Benzaldehydes
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We report Pd-catalyzed ortho-C-H methoxylation and chlorination of benzaldehydes by employing monodentate transient directing groups (TDGs) as an alternative strategy to bidentate TDGs. More importantly, a single crystal of benzaldehyde imine ortho-cyclopalladium intermediate was successfully obtained, and its structure was unambiguously determined by X-ray diffraction, which clearly showed that it was a binuclear palladium species bridged by a pyridone ligand. The utility of this approach was further demonstrated through the synthesis of key intermediates of natural products and drugs.
- Li, Feng,Zhou, Yirong,Yang, Heng,Wang, Ziqi,Yu, Qinqin,Zhang, Fang-Lin
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supporting information
p. 3692 - 3695
(2019/05/24)
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- Pd-Catalyzed, ortho C-H Methylation and Fluorination of Benzaldehydes Using Orthanilic Acids as Transient Directing Groups
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The direct, Pd-catalyzed ortho C-H methylation and fluorination of benzaldehydes have been accomplished using commercially available orthanilic acids as transient directing groups. In these reactions, the 1-fluoro-2,4,6-trimethylpyridinium salts can be either a bystanding F+ oxidant or an electrophilic fluorinating reagent. An X-ray crystal structure of a benzaldehyde ortho C-H palladation intermediate was obtained using triphenylphosphine as the stabilizing ligand.
- Chen, Xiao-Yang,Sorensen, Erik J.
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supporting information
p. 2789 - 2792
(2018/03/08)
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- IBX works efficiently under solvent free conditions in ball milling
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IBX (2-iodoxybenzoic acid), discovered in 1893, is an oxidant in synthetic chemistry whose extensive use is impeded by its explosiveness at high temperature and poor solubility in common organic solvents except DMSO. Since the discovery of Dess-Martin Periodinane in 1983, several modified IBX systems have been reported. However, under ball milling conditions, IBX works efficiently with various organic functionalities at ambient temperature under solvent free conditions. Also, the waste IBA (2-iodosobenzoic acid) produced from the reactions was in situ oxidized to IBX in the following step using oxone and thus reused for multiple cycles by conserving its efficiency (only ~6% loss after 15 cycles). This work describes an overview of a highly economical synthetic methodology which overcomes the problems of using IBX, efficiently in gram scale and in a non-explosive way. This journal is the Partner Organisations 2014.
- Achar, Tapas Kumar,Maiti, Saikat,Mal, Prasenjit
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p. 12834 - 12839
(2014/04/03)
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- PHARMACEUTICAL COMPOSITION AND PROCESS
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There is provided a formulation comprising N-(2-chloro-6-methylbenzoyl)-4- [(2,6-dichlorobenzoyl)amino]-L-phenylalanine-2(diethylamino)ethyl ester and poloxamer 188 which is manufactured by a hot melt process.
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Page/Page column 7
(2008/06/13)
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- 1,2-BIS-(SUBSTITUTED-PHENYL)-2-PROPEN-1-ONES AND PHARMACEUTICAL COMPOSITIONS THEREOF
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The invention relates to compounds, pharmaceutical compositions and methods of using compounds of the general formula (I), or its pharmaceutically acceptable salt or ester, wherein the substituents are defined in the application.
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Page/Page column 124-125
(2010/02/15)
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- NITROGENOUS HETEROCYCLIC DERIVATIVE HAVING 2,6-DISUBSTITUTED STYRYL
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The invention provides a novel nitrogen-containing heterocyclic derivative having 2,6-disubstituted styryl and a pharmaceutically acceptable salt thereof, and a pharmaceutical composition comprising the nitrogen-containing heterocyclic derivative and a pharmaceutically acceptable salt thereof, in particular, a pharmaceutical composition effective as a sodium channel inhibitor, having an excellent analgesic action especially on neuropathic pain with minimized side effects.
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Page/Page column 14
(2010/02/14)
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- Substituted 1-(4-aminophenyl)pyrazoles and their use as anti-inflammatory agents
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1-(4-aminophenyl)pyrazoles optionally substituted on the 3- and 5-positions of the pyrazole ring and on the amino group at the 4-position of the phenyl ring are disclosed and described, which pyrazoles inhibit IL-2 production in T-lymphocytes.
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- Two efficient methods for the preparation of 2-chloro-6-methylbenzoic acid
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Two efficient methods for the preparation of 2-chloro-6-methylbenzoic acid were developed: one based on nucleophilic aromatic substitution and the other based on carbonylation. In the first approach, 2-chloro-6-fluorobenzaldehyde was converted to its n-butylimine, then treated with 2 equiv of methylmagnesium chloride in THF to give, after hydrolysis, 2-chloro-6-methylbenzaldehyde. Subsequent oxidation of this compound gave the title compound in 85% overall yield. In the second approach, 3-chloro-2-iodotoluene was efficiently carbonylated in methanol to give methyl 2-chloro-6-methylbenzoate, which after hydrolysis afforded the title compound in 94% yield (84% yield after recrystallization). The carbomethoxylation proceeded smoothly even at a high substrate-to-Pd ratio of 10 000. Both methods do not require isolation of intermediates and are suitable for the preparation of kilogram quantities of 2-chloro-6-methylbenzoic acid.
- Daniewski, Andrzej R.,Liu, Wen,Puentener, Kurt,Scalone, Michelangelo
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p. 220 - 224
(2013/09/06)
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- N-aroylphenylalanine derivative VCAM-1 inhibitors
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Compounds of the formula: are disclosed which have activity as inhibitors of binding between VCAM-1 and cells expressing VLA-4. Such compounds are useful for treating diseases whose symptoms and/or damage are related to the binding of VCAM-1 to cells expr
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- Thioamide derivatives
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It has been discovered that compounds of the formula: and the pharmaceutically acceptable salts and esters thereof wherein X and Y are as defined below, inhibit the binding of VCAM-1 to VLA-4 and are useful in treating inflammation associated with chronic inflammatory diseases such as rheumatoid arthritis (RA), multiple sclerosis, (MS), asthma, and inflammatory bowel disease (I BD).
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- Synthesis of 9,10-dihydrosilaanthracenes with substituents ortho to the silicon and methylene bridges
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The generation of 9,10-dihydrosilaanthracenes with substituents on benzo ring carbons, specifically in the 4,5-positions adjacent to the methylene bridge, has been developed.Attempts to prepare the 1,8-isomer where the substituents are adjacent to the silicon bridge are also described.The diarylmethane precursors to the substituted 9,10-dihydrosilaanthracenes required the synthesis of 2,3-dihalotoluenes as well as isomeric 2,6-disubstituted benzaldehydes which were then condensed to diarylmethanols through the Grignard reagents.Ring closure to the 4,5-dimethyl-9,9-dialkyl-9,10-dihydro-9-silaanthracene, I, required the use of Rieke magnesium.The structure of I (alkyl = iPr) was determined and demonstrates that the introduction of substituents adjacent to the methylene bridge causes the dihydrosilaanthracene framework to become nearly planar with a dihedral (or butterfly) angle of 170 deg C.
- Bedard, Thomas C.,Corey, Joyce Y.,Lange, Lura D.,Rath, Nigam P.
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p. 261 - 272
(2007/10/02)
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- Ortho Metalation Directed by α-Amino Alkoxides
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The addition of aromatic aldehydes to certain lithium dialkylamides in benzene or tetrahydrofuran gave α-amino alkoxides which were ortho lithiated with excess n-butyllithium.Subsequent alkylation and hydrolysis provided ortho-substituted aromatic aldehydes via a one-pot reaction.The ortho metalation of α-amino alkoxides derived from 1- and 2-naphthaldehyde and various substituted benzaldehydes was examined.When N,N,N'-trimethylethylenediamine was used as the amine component of the α-amino alkoxide, metalation could be carried out at lower temperatures.This rate increase is due to an intramolecular TMEDA-like assisted metalation.The synthetic utility of this ortho metalation, including how varying the amine component of the α-amino alkoxide affects the regiochemistry and metalation rate, is discussed.
- Comins, Daniel L.,Brown, Jack D.
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p. 1078 - 1083
(2007/10/02)
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- Antihypertensive Activity of 6-Arylpyridopyrimidin-7-amine Derivatives
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A series of 51 6-arylpyridopyrimidin-7-amine derivatives was prepared and evaluated for antihypertensive activity in the conscious spontaneously hypertensive rat.A number of these compounds, notably 6-(2,6-dichlorophenyl)-2-methylpyridopyrimidin-7-amine (36), lowered blood pressure in these rats in a gradual and sustained manner to normotensive levels at oral doses of 10-50 mg/kg.Normalized blood pressure levels could then be maintained by single daily oral doses.The effect of structural variation in the 6-aryl group and in the 2 and 4 positions of the pyridopyrimidine ring on activity is reported and discussed.
- Bennett, Lawrence R.,Blankley, C. John,Fleming, Robert W.,Smith, Ronald D.,Tessman, Deirdre K.
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p. 382 - 389
(2007/10/02)
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