- Novel preparation method of antihypertensive drug telmisartan intermediate
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The invention relates to an electric reduction preparation method of aminobenzoic acid represented by formula I and ester thereof. The preparation reaction of the method is shown in the description; and in the reaction formula, R is selected from hydrogen, a methyl group, an ethyl group, a benzyl group, a C3 or C4 straight-chain alkyl or branched-chain alkyl group, -NO2 is selected from 4-NO2 or 5-NO2, and Y is selected from H or 4-NHCOC3H7-n. The electroreduction preparation method of aminobenzoic acid and ester I thereof is characterized in that in a separated electrolytic cell, an acidic solution of nthe itrobenzoic acid and ester III thereof is taken as a catholyte; the voltage of a cathode working electrode relative to a reference electrode is 1.00-2.50 V; and an anolyte is an acidicsolution, the current density is 25.0-250.0 mA/cm, and the electrolysis temperature is 15-90 DEG C.
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Paragraph 0074-0080
(2021/06/26)
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- High Turnover Pd/C Catalyst for Nitro Group Reductions in Water. One-Pot Sequences and Syntheses of Pharmaceutical Intermediates
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Commercially available Pd/C can be used as a catalyst for nitro group reductions with only 0.4 mol % Pd loading. The reaction can be performed using either silane as a transfer hydrogenating agent or simply a hydrogen balloon (μ1 atm pressure). With this technology, a series of nitro compounds was reduced to the desired amines in high chemical yields. Both the catalyst and surfactant were recycled several times without loss of reactivity.
- Gallou, Fabrice,Li, Xiaohan,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
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supporting information
p. 8114 - 8118
(2021/10/25)
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- Preparation method of benzimidazole compound
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The invention belongs to the field of pharmaceutical chemicals, and particularly relates to a preparation method of a benzimidazole compound. The benzimidazole compound is prepared by taking a halogenated benzoic acid amine compound as a reaction raw material through azidation reaction and cyclization reaction. The benzimidazole compound with high yield and high purity can be obtained, and the method is suitable for industrial production.
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Paragraph 0029-0030
(2021/04/10)
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- Synthetic method 2 - n-propyl -4 - methyl -6 - (1 -methylbenzimidazole -2 -yl) benzimidazole (by machine translation)
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The invention relates to the technical field of synthesis of medical intermediates, and discloses a synthesis method of 2 - n-propyl -4 - methyl -6 - (1 -methylbenzimidazole -2 -yl) benzimidazole; S1: a condensation closed loop is obtained; and the reaction temperature is controlled to 3 - and the intermediate IV is N - [-4 - methyl -5 - (40 - 110 °C-methylbenzimidazole) 2 -nitrophenyl]-butylamide; S2: a reduction ring; and the preparation method comprises the following steps: S3: condensation ring-ring synthesis and intermediate IV of -4 -propyl -4 - 1 -6 - methyl 1 - S4 -2 - (-6 -methylbenzimidazol 2 -yl) benzimidazole -2 . 2 - N-propyl -4 - methyl -6 - (1 -methylbenzimidazole -2 -yl) benzimidazole is higher in purity, reduced in impurities and high in yield. (by machine translation)
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Paragraph 0029-0034; 0043-0046; 0055-0058; 0067-0070
(2020/10/04)
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- Synthesis method of telmisartan intermediate 4-amino-3-methylbenzoic acid
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The invention discloses a synthesis method of telmisartan intermediate 4-amino-3-methylbenzoic acid. According to the synthesis method, 2-methylaniline reacts with chloroformate under the action of acatalyst to obtain the 4-amino-3-methylbenzoic acid. The synthesis method has the advantages of few reaction step, easy availability of raw materials, few side reaction, high reaction yield, high product purity, low process cost, simple post-treatment operation, no pollution and no emission.
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Paragraph 0036-0041
(2019/05/21)
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- Preparation method of 3-methyl-4-aminobenzoic acid
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The invention provides a preparation method of 3-methyl-4-aminobenzoic acid and belongs to the technical field of chemical synthesis. According to the method, 3-methyl-4-nitrobenzoic acid and a quaternary ammonium salt type phase-transfer catalyst are added to a reaction device, a solvent is added, the mixture is stirred uniformly, reduced iron powder and protonic acid are added to react, and a reaction liquid is obtained; then the reaction device is cooled, sodium carbonate and activated carbon are added for decoloration, the PH value is adjusted to be alkaline, iron mud is filtered and washed twice with a sodium carbonate solution, a filtered stock and cleaning fluids are mixed, and a light yellow solution is obtained; acid is added to the light yellow solution until the PH value is adjusted to be slightly acid, off white precipitates are separated out, filtered, washed with water and dried, and 3-methyl-4-aminobenzoic acid is obtained. The preparation method is simple, low in cost and more suitable for industrial production, and the product yield reaches 90.1% at most.
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Paragraph 0029-0059
(2017/08/30)
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- Method for preparing 3-methyl-4-aminobenzoic acid through catalytic hydrogenation
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The invention provides a method for preparing 3-methyl-4-aminobenzoic acid through catalytic hydrogenation, belonging to the technical field of chemical synthesis. The method comprises the following steps: adding 3-methyl-4-nitrobenzoic acid and a solvent into a reaction vessel so as to obtain a 3-methyl-4-nitrobenzoic acid solution, and adjusting the pH value of the solution to be alkaline; pouring the obtained alkaline aqueous solution into an autoclave, adding a catalyst, respectively carrying out replacement with nitrogen and hydrogen for three times, introducing ammonia gas for 2 minutes, carrying out pressurizing with hydrogen to 3.45 MPa to 4.50 MPa, and carrying out a reaction under the pressure of 4.50 to 2.50 MPa at 100 to 160 DEG C so as to obtain a reaction solution; and subjecting the reaction solution to post-processing so as to obtain the 3-methyl-4-aminobenzoic acid. The method provided by the invention has the advantages of easily-available raw materials, simple operation, low production amount of three wastes, environmental friendliness, capability of reaching a mole yield up to 90%, and more applicability to industrial production.
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Paragraph 0025-0047
(2018/01/12)
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- One-pot synthesis of 1,4-disubstituted 1,2,3-triazoles from nitrobenzenes
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A facile synthesis of 1,4-disubstituted 1,2,3-triazoles was achieved from nitrobenzenes and terminal alkynes under mild conditions. The reactions were successful for nitrobenzenes and terminal alkynes bearing various functionalities, from which the 1,2,3-triazole derivatives were smoothly synthesized through a four-step one-pot sequence.
- Zhao, Fen,Chen, Zhen,Xie, Kai,Yang, Rui,Jiang, Yu-Bo
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p. 109 - 113
(2016/01/25)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds and compositions and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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Paragraph 0175
(2014/05/24)
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- One-pot palladium-catalyzed synthesis of selectively substituted phenanthridines by sequential aryl-aryl and heck couplings, aza-michael and retro-mannich reactions
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A catalytic synthesis of selectively substituted phenanthridines is achieved through a reaction sequence involving palladium/norbornene-catalyzed unsymmetrical aryl-aryl and Heck couplings followed by aza-Michael and retro-Mannich reactions. In spite of the many steps involved the method is very simple and allows the formation of selectively substituted phenanthridines under mild conditions in a straightforward one-pot reaction starting from readily available aryl iodides and bromides.
- Della Ca, Nicola,Motti, Elena,Mega, Antonio,Catellani, Marta
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supporting information; experimental part
p. 1451 - 1454
(2010/08/19)
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- Acidity of benzoic acids bearing the (CO)5Cr=CN(CH 3)2 group
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Benzoic acids 2a and 2b, bearing the (CO)5Cr=CN(CH 3)2 group in the p- and m-position, and the corresponding benzoic acids 2c and 2d, in which the rotation of the aminocarbene moiety was blocked by the presence of a methyl group, were prepared together with the corresponding N,N-dimethylamido acids 3a-d. The measurement of pKa values in EtOH and DMF revealed that the (CO)5Cr=CN(CH 3)2 group is a very weak electron acceptor (δp = 0; δm = 0.14). The restriction of the rotation of the aminocarbene moiety did not significantly influence its electronic properties. The obtained results are in accordance with earlier findings that the relatively strong acidity of carbene complexes bearing hydrogens at the ±-position to the carbene atom is due to the resonance stabilization of the anion.
- Parik, Patrik,Kulhanek, Jiri,Ludwig, Miroslav,Wagner, Roman,Rotrekl, Ivan,Drahonovsky, Dusan,Meca, Ludek,Smidkova, Marketa,Tobrman, Tomas,Dvorak, Dalimil
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experimental part
p. 4135 - 4138
(2011/01/03)
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- Concise synthesis of telmisartan via decarboxylative cross-coupling
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(Chemical Equation Presented) An efficient synthesis of the angiotensin II receptor antagonist telmisartan is presented involving a decarboxylative cross-coupling of isopropyl phthalate (1) with 2-(4-chlorophenyl)-1,3-dioxolane (2c) as the key step (85% yield). The benzimidazole moiety is constructed regioselectively via a reductive animation-condensation sequence, replacing the previously published route via alkylation of the preformed benzimidazole. The product is obtained in an overall yield of 35% in a convergent synthesis with the longest sequence consisting of eight steps.
- Goossen, Lukas J.,Knauber, Thomas
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supporting information; experimental part
p. 8631 - 8634
(2009/04/11)
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- FUSED TRICYCLIC COMPOUNDS AS INHIBITORS OF TUMOR NECROSIS FACTOR-ALPHA
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Compounds of formula (1): are disclosed, wherein V is CH2; W is S(O)m; m is the integer 0, 1 or 2; U is O, C(O), CR13R14 or NR15; where R13 is H, alkyl; R14 is H, OH, OR13 or OCOR13; R15 is H, alkyl, cycloalkyl, alkenyl, C(O)R13, C(O)OR13 or alkylaminocarbonyl; R1, R2, R3, R4, R5, R6, R7 and R8 are as defined herein. These compounds are inhibitor of tumor necrosis factor-alpha (TNF- ) and are useful as medicaments for the treatment and prevention of disorders caused by increased TNF- activity, in particular inflammations.
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Page/Page column 53-54
(2010/11/30)
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