- Preparation method of 5-chloro-2-aminobenzoic acid intermediate
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The invention discloses a preparation method of 5-chloro-2-aminobenzoic acid, and belongs to the technical field of organic synthesis, the preparation method specifically comprises the following steps: dissolving 2, 5-dichlorotoluene in a solvent, adding an oxidant while stirring, heating to 50-80 DEG C, carrying out heat preservation reaction for 3-6 hours, recovering the organic solvent after the reaction is finished, adding water, filtering while hot, and adjusting the pH value of the filtrate to 2 by using hydrochloric acid, obtaining 2, 5-dichlorobenzoic acid through cooling, crystallization and filtering, adding 2, 5-dichlorobenzoic acid into an organic solvent to be dissolved, addign a metal catalyst, alkali and an ammonia source, heating the mixture to 70-150 DEG C and then performing a heat preservation reaction for 8-15 h, performing reduced pressure distillation after the reaction is finished, and obtaining 5-chloro-2-aminobenzoic acid. A new path for synthesizing 5-chloro-2-aminobenzoic acid is designed, the preparation method is simple, easy to operate, low in cost and environmentally friendly, and N, N-dimethylglycine is added in the ammoniation reaction process, so that the temperature of the ammoniation reaction can be reduced, the reaction time can be shortened, and the reaction yield can be increased.
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Paragraph 0017-0020
(2021/08/11)
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- Irsogladine maleate preparation method
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The invention belongs to the field of organic matter synthesis, and particularly relates to an irsogladine maleate preparation method, wherein p-dichlorobenzene is used as a starting raw material, andfive reactions of acetylation, bromoform reaction, cyanation, cyclization and salt formation are performed to prepare the target compound. According to the present invention, the new irsogladine maleate preparation method is used, can significantly accelerate the reaction rate and improve the yield, has advantages of cost reducing, environment protection, simple operation and convenient post-treatment, and is suitable for industrial production.
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Paragraph 0009; 0010
(2019/05/16)
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- Pharmaceutical intermediate 2,5-dichlorobenzoic acid synthesis method
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The invention relates to a pharmaceutical intermediate 2,5-dichlorobenzoic acid synthesis method, which mainly comprises: adding 2 mol 2,5-dichloro-6-aminobenzoic acid and 3-5 mol diisobutyl adipate solution to a reaction container, increasing the solution temperature to 70-78 DEG C, controlling the stirring speed at 130-160 rpm, adding 3-4 mol cobalt naphthenate in 3-5 times every 30-40 min, continuously carrying out the reaction for 90-120 min, adding 1200 ml of a potassium chloride solution, layering the solution, reducing the solution temperature to 10-15 DEG C, adding an oxalic acid solution, adjusting the pH value to 4-5, washing with a potassium sulfate solution, washing with a methyl tert-butyl ether solution, washing with a 2-methyl tetrahydrofuran solution, carrying out pressurereducing distillation, collecting the distillate at a temperature of 110-120 DEG C, and dehydrating with a dehydrating agent to obtain the finished product 2,5-dichlorobenzoic acid.
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Paragraph 0006; 0009-0014
(2018/07/30)
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- Flow carbonylation of sterically hindered ortho-substituted iodoarenes
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The flow synthesis of ortho-substituted carboxylic acids, using carbon monoxide gas, has been studied for a number of substrates. The optimised conditions make use of a simple catalyst system compromising of triphenylphosphine as the ligand and palladium acetate as the pre-catalyst. Carbon monoxide was introduced via a reverse "tube-in-tube" flow reactor at elevated pressures to give yields of carboxylated products that are much higher than those obtained under normal batch conditions.
- Mallia, Carl J.,Walter, Gary C.,Baxendale, Ian R.
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supporting information
p. 1503 - 1511
(2016/08/02)
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- Conformations, equilibrium thermodynamics and rotational barriers of secondary thiobenzanilides
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The article deals with conformational behaviour of 2-methoxy-2′-hydroxythiobenzanilides. The CS-NH group of these compounds preferentially adopts the Z-conformation. Entropy favours the Z-conformer over the E-conformer, whereas enthalpy slightly favours the E-conformer over the Z-conformer. The rotational barrier about the CS-NH bond was determined to be (81.5±0.4) kJ/mol. No significant rotational barrier was found on the Ar-CS and Ar-NH bonds. All experimental outcomes are compared with the results of quantum-chemical calculations.
- Kozic, Ján,Novák, Zdeněk,?ímal, Václav,Profant, Václav,Kune?, Ji?í,Vin?ová, Jarmila
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p. 2072 - 2083
(2016/04/09)
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- Theoretical and experimental study on the reactivity of methyl dichlorobenzoates with sulfur-centered nucleophiles by electron transfer reactions
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Reactions of methyl 2,5-dichlorobenzoate or methyl 3,6-dichloro-2- methoxybenzoate with sulfur-centered nucleophiles gave mono- and disubstitution products, respectively through SRN1 mechanism in liquid ammonia. Products obtained could be potential herbicides less toxic to the environment. Theoretical studies explained the reactivity observed considering geometries, and spin densities of radical anions and potential energy surfaces for the dissociation of the radical anions formed.
- Uranga, Jorge G.,Monta?ez, Juan P.,Santiago, Ana N.
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experimental part
p. 584 - 589
(2012/02/05)
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- SPIRO AMINO COMPOUNDS SUITABLE FOR THE TREATMENT OF INTER ALIA SLEEP DISORDERS AND DRUG ADDICTION
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The invention concerns a spiro-amino compound of Formula (Vl) wherein m is 1 or 2 or 3, n is 1 or 2, R is selected from a 5- or 6-membered aromatic ring and a 5- or 6-membered heteroaromatic ring comprising 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (C1-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (C1-C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom; P is a substituent Q or COQ, wherein Q is selected from the group consisting of phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (C1-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy or a pharmaceutically acceptable salt thereof.
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Page/Page column 69
(2011/02/24)
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- Proton transfer equilibria between disubstituted benzoic acids and carbinol base of crystal violet in apolar aprotic solvents. Chemometric analysis of disubstituent effects on the strength of benzoic acid in chlorobenzene
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Proton transfer equilibria in chlorobenzene between a set of di-substituted (2,3-,2,5-,2,6-, 3,5-dichloro and difluoro) benzoic acids including the corresponding mono-substituted acids and the carbinol base of crystal violet have been studied spectrophotometrically. To investigate the effect of disubstitution at ortho- and/or meta- positions on the strength of benzoic acid, the results have been analysed chemometrically on the basis of Fujita Nishioka's multiparameter approach and the assumption of additivity for substituent effects. The model employed explains 94% of the variance for the disubstituent effects on log K. It is observed that the substituent effect is contributed by ordinary electronic and proximity electronic effects in an almost equal ratio (52:48).
- Sen Gupta, Susanta K.,Shrivastava, Ruchi
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p. 369 - 373
(2008/09/19)
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- Regeneration of carbonyl compounds from oximes, semicarbazones and tosylhydrazones with calcium hypochlorite and moist montmorillonite K-10
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Oximes, semicarbazones and tosylhydrazones are converted into the corresponding carbonyl compounds in the presence of calcium hypochlorite and moist montmorillonite K-10 under mild and heterogeneous conditions.
- Movassagh, Barahman,Dahaghin, Ebrahim
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p. 1541 - 1543
(2007/10/03)
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- Electrocarboxylation of chlorinated aromatic compounds
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Chorinated benzenes (1, 4), biphenyls (6, 9), dibenzofurans (10, 15, 17, 18), 2-chlorodibenzo[1,4]dioxine (24) and 1-chloronaphthalene (26) as well as dibenzofuran (12) and naphthalene (27) themselves were transformed into carboxylic acids by galvanostatic electroreduction in the presence of carbon dioxide ("electrocarboxylation"). Dry DMF was used as solvent, zinc or stainless steel as cathode and magnesium as a sacrificial anode in an undivided cell. Hydrogenation of aromatic rings was not observed. However, reductive addition of two molecules of carbon dioxide to form dihydrodicarboxylic acids, e.g. 22 and 29, occurs in the dibenzofuran and naphthalene series.
- Golinske, Dirk,Voss, Juergen,Adiwidjaja, Gunadi
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p. 862 - 880
(2007/10/03)
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- Natural formation of chlorobenzoic acids (CBA) and distinction between PCB-degraded CBA
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Mono- and dichlorobenzoic acid (CBA) could be found in samples of remote bog pond water and sediment. The 2,4-CBA always had the highest concentrations. In bog water samples the concentrations ranged between 0.11 and 0.48 μg/l. Besides 2,4-CBA most only 2,5-CBA could be found as dichlorobenzoic acid. In all samples we could detect also trichloroacetic acid (TCAA). The TCAA concentrations correlate with the CBA concentrations. As TCAA is known as a naturally produced organohalogen, this correlation can be seen as an indication to a natural formation of CBA. A confirmation of this presumption is our detection CBA in a reaction of benzoic acid with the chlorinating enzyme chloroperoxidase (CPO).
- Niedan,Schoeler
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p. 1233 - 1241
(2007/10/03)
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- Electrosynthesis of aryl-carboxylic acids from chlorobenzene derivatives and carbon dioxide
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The electrocarboxylation of a large variety of chlorobenzenic compounds is achieved in N,N-dimethylformamide by constant current electrolysis between a stainless steel cathode and a sacrificial magnesium anode in a diaphragmless cell. Substituted benzoic acids are obtained in high yield in simle conditions thus avoiding the usual preparation of organometallic intermediates.
- Heintz, Monique,Sock, Oumar,Saboureau, Christophe,Perichon, Jacques,Troupel, Michel
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p. 1631 - 1636
(2007/10/02)
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