- Simple and environment-friendly chemical synthesis method of 4-fluoro-2-methyl benzoic acid
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The invention relates to a simple and environment-friendly chemical synthesis method of 4-fluoro-2-methyl benzoic acid. According to the synthesis method, m-fluorotoluene and acetyl chloride are takenas starting raw materials, and are subjected to a Friedel-Crafts acylation reaction under the catalytic action of anhydrous aluminum trichloride, a haloform reaction is carried out with sodium hypochlorite, two isomers of 4-fluoro-2-methyl benzoic acid and 2-fluoro-4-methyl benzoic acid are simultaneously obtained after hydrolysis, and the isomers are separated through re-crystallizing so as to obtain the target product 4-fluoro-2-methylbenzoic acid. The route is mild in reaction condition, low in cost, environment-friendly and suitable for industrial production.
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Paragraph 0003
(2020/04/02)
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- Chemical synthesis method of 4-fluoro-2-methyl benzoic acid
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The invention relates to a chemical synthesis method of 4-fluoro-2-methyl benzoic acid. According to the synthesis method, m-fluorotoluene and trichloroacetyl chloride are used as starting raw materials, and are subjected to a Friedel-Crafts acylation reaction under the catalytic action of anhydrous aluminum trichloride, hydrolysis and acidification are performed under an alkaline condition to obtain two isomers of 4-fluoro-2-methyl benzoic acid and 2-fluoro-4-methyl benzoic acid, and the isomers are separated through re-crystallizing to obtain the target product 4-fluoro-2-methylbenzoic acid.The method has the advantages of accessible raw materials, mild reaction conditions and low cost, and is suitable for industrial production.
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Page/Page column 4; 5
(2020/04/02)
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- Palladium-Catalyzed ortho-C-H Methylation of Benzoic Acids
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A palladium-catalyzed methylation of C-H bonds of benzoic acids with di-tert-butyl peroxide as the methylating reagent under an external oxidant and ligand-free conditions has been achieved. The reaction is found to be directed by a weakly coordinating carboxyl group, offering a facile route for the synthesis of highly functionalized ortho-methyl benzoic acids.
- Lv, Weiwei,Wen, Si,Liu, Jing,Cheng, Guolin
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p. 9786 - 9791
(2019/08/26)
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- Site- and regio-selective incorporation of carbon dioxide into the C(sp2)Si bond of benzosilacyclobutenes
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A reaction of benzosilacyclobutenes with carbon dioxide is catalyzed by a nickel complex having an N-heterocyclic carbene ligand. Carbon dioxide inserts into the C(sp2)Si bond in a site- and regio-selective manner to form a carboncarbon bond, furnishing benzoic acid derivatives.
- Ishida, Naoki,Okumura, Shintaro,Murakami, Masahiro
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supporting information
p. 570 - 572
(2018/04/12)
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- INHIBITORS OF STEAROYL-COA DESATURASE
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Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, obesity.
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- ISOINDOLONE COMPOUNDS AND THEIR USE AS METABOTROPIC GLUTAMATE RECEPTOR POTENTIATORS
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The present invention is directed to compounds of formula (I), wherein R1 is a ring and n is a number from 1 to 8. The invention also relates to use of the compounds in therapy as metabotropic glutamate receptor modulators, particularly in neurological and psychiatric disorders.
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Page/Page column 56-57
(2008/06/13)
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- Synthesis of aromatic carboxylic acids by carbonylation of aryl halides in the presence of epoxide-modified cobalt carbonyls as catalysts
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A new procedure was developed for synthesis of aromatic and heteroaromatic acids and their derivatives (esters, salts) by carbonylation of the corresponding aryl halides. The acids are selectively formed in a high yield under very mild conditions. Highly active catalytic systems, base-containing alcoholic solutions of cobalt carbonyl modified with epoxides, were used to activate aryl halides. 2005 Pleiades Publishing, Inc.
- Boyarskii,Zhesko,Lanina
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p. 1844 - 1848
(2007/10/03)
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- The first regioselective metalation and functionalization of unprotected 4-halobenzoic acids
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(Chemical Equation Presented) By treatment with s-BuLi, s-BuLi/TMEDA, or t-BuLi at ~-78°C, 4-fluoro- and 4-chlorobenzoic acids (1a,b) are metalated preferentially in the position adjacent to the carboxylate. A complete reversal in regioselectivity is observed for 1a when treated with LTMP; a sequential process involving a rapid intraaggregate lithiation through a quasi dianion complex "QUADAC" is postulated to explain the unusual reactivity of Me2S2 and I2.
- Gohier, Frederic,Castanet, Anne-Sophie,Mortier, Jacques
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p. 1501 - 1504
(2007/10/03)
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- ANILINOPYRAZOLE DERIVATIVES USEFUL FOR THE TREATMENT OF DIABETES
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The present invention relates to anilinopyrazole compounds, pharmaceutical compositions, and methods for treating diabetes and related disorders.
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- Aromatic heterocyclic derivatives as enzyme inhibitors
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The present invention discloses peptide aldehydes which are potent and specific inhibitors of thrombin, their pharmaceutically acceptable salts, pharmaceutically acceptable compositions thereof, and methods of using them as therapeutic agents for disease states in mammals characterized by abnormal thrombosis.
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Page column 118
(2010/02/04)
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- Aromatic heterocyclic derivatives as enzyme inhibitors
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The present invention discloses peptide aldehydes which are potent and specific inhibitors of thrombin, their pharmaceutically acceptable salts, pharmaceutically acceptable compositions thereof, and methods of using them as therapeutic agents for disease states in mammals characterized by abnormal thrombosis.
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- (2-methyl-5-(methylsulfonyl)benzoyl)guanidine Na+/H+ antiporter inhibitors
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The inhibition of the Na+/H+ exchanger during cardiac ischemia and reperfusion has been shown to be beneficial for the preservation of the cellular integrity and functional performance. The aim of the present investigation was to come up with potent and selective benzoylguanidines as NHE inhibitors for their use as an adjunctive therapy in the treatment of acute myocardial infarction. During the course of our investigations it became clear that the substitution ortho to the acylguanidine was of crucial importance for the potency of the compounds. 4-Chloro and 4-fluoro-2- methylbenzoic acids 6 and 7 were prepared using the directed ortho metalation technique with the carboxylic acid as the directing group. With the LDA/methyl iodide system the 2-methyl group could be extended to an ethyl group. 4-Alkyl groups were inserted by the palladium-catalyzed cross-coupling reaction into the 4-bromo-2-methylbenzoic acid methyl ester (20). Starting with benzoic acids 6-19, the methylsulfonyl group was introduced by a sequence of standard reactions (sulfochlorination, reduction, and methylation). 4-Aryl derivatives 6875 were synthesized by the palladium- catalyzed Suzuki reaction. A large number of nucleophilic displacement reactions in the 4-position were carried out with S-, O-, and N-nucleophiles as well as with the cyano and trifluoromethyl group. Using the ester method, acid chlorides, or Mukaiyama's procedure, the 5-(methylsulfonyl)benzoic acid derivatives were finally converted to the (5- (methylsulfonyl)benzoyl)guanidines 165-267 with excessive guanidine. In some cases nucleophilic substitutions with pyridinols and piperidine derivatives were carried out at the end of the reaction sequence with the 4-halo-N- (diaminomethylene)-5-(methylsulfonyl)benzamides. Variations in the 4-position were most reasonable, but the volume of the substituents was of crucial importance. Substitution in the 3- and particularly in the 6-position led to considerable worsening of the inhibitory effects of the Na+/H+ exchanger. The 2-methyl compounds, however, showed without exception higher in vitro activities than their respective demethyl counterparts as they are exemplified by the reference compounds 266 and 267, obviously caused by a conformational restriction of the acylguanidine chain. The development compound (2-methyl-5-(methylsulfonyl)-4-pyrrolobenzoyl)guanidine, methanesulfonate (246) is a NHE-1 subtype specific NHE inhibitor, being 27- fold more potent toward the NHE-1 than the NHE-2 isoform, 246 was found to act cardioprotectively not only when given before an experimentally induced ischemia, but also curatively after the onset of symptoms of acute myocardial infarction when given prior to the induction of reperfusion.
- Baumgarth, Manfred,Beier, Norbert,Gericke, Rolf
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p. 2017 - 2034
(2007/10/03)
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- Process for the preparation of halogenated benzoic acids
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A process for the preparation of halogenated benzoic acids of formula (1): STR1 in which R1, R2, R3, R4 and R5 are hydrogen, fluorine, chlorine or bromine atoms or C1 -C6 -alkyl, C1 -C6 -alkoxy, nitro, cyano, trifluoromethyl, aidehyde, C1 -C4 -alkoxycarbonyl, -SO2 -C1 -C4 -alkyl, -SO2 -phenyl, -CONH2, -CON(C1 -C4 -alkyl)2, hydroxy, carboxy, -NH2 or -N(C1 -C4 - alkyl)2 groups, at least one of the substituents R1 -R5 being one of said halogen atoms, which comprises reacting 1 mol of a benzophenone, asymmetrically substituted on the benzene rings A and B, of general formula (2): STR2 in which R1 -R10 are as defined above for R1 -R5, with about 1 to about 10 mol of an oxidizing agent selected from the group comprising hydrogen peroxide, urea/hydrogen peroxide addition product, an alkali metal peroxide, ammonium, alkali metal or alkaline earth metal peroxodisulfates, pertungstates, perborates or percarbonates, ozone, alkyl- or aryl-percarboxylic acids, alkyl- or aryl-persulfonic acids or persulfuric acid, at temperatures from about -20° to about +100° C.
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- Directed lithiation of unprotected benzoic acids
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Benzoic acid gives the ortho-lithiated species 1 under standard conditions (s-BuLi-TMEDA-THF, -90 deg C).Reaction of 1 at -78 deg C with either methyl iodide, dimethyl disulfide, hexachloroethane, or 1,2-dibromotetrachloroethane gives the ortho-substituted product.Intramolecular competition between the carboxylic acid and methoxy, chloro, fluoro, or diethylamido functions in ortho- and -para-substituted benzoic acids establishes the carboxylic acid group to be of intermediate capacity in directing metallation.Complimentarity of directing effects is observed with the chloro and fluoro groups in the meta-substituted benzoic acid but not with the methoxy and trifluoromethyl groups.Electrophile introduction into meta- and para-lithiated benzoates occurs with equal efficacy and comparable scope.The 2,4-dihalogenobenzoic acids undergo hydrogen/metal exchange at the position flanked by both halogen substituents. 2,2-Difluoro-1,3-benzodioxole-4-carboxylic acid undergoes lithiation adjacent to the oxygen atom.By use of such methods, routes to benzoic acids contiguously tri- and tetra-substituted with a variety of functionalities have been developed.
- Bennetau, Bernard,Mortier, Jacques,Moyroud, Joel,Guesnet, Jean-Luc
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p. 1265 - 1272
(2007/10/02)
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