1975-50-4Relevant articles and documents
Preparation of 2-arylindole-4-carboxylic amide derivatives
Kuethe, Jeffrey T.,Davies, Ian W.
, p. 11381 - 11390 (2006)
A practical, highly efficient protocol has been developed for the synthesis of functionalized 2-arylindole-4-carboxylic amide derivatives. Commercially available methyl 2-methyl-3-nitrobenzoate gave substituted nitrostyrene benzoic acids by reaction with aromatic aldehydes in the presence of DBU in DMSO. Conversion of these products to the desired amides was followed by Pd-catalyzed reductive cyclization employing carbon monoxide as the terminal reductant to provide the 2-arylindole-4-carboxylic amide derivatives in excellent overall yield for the simple three-step sequence.
Method for co-production 2-methyl-6-nitrobenzoic acid and 3-nitro-2-methylbenzoic acid
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Paragraph 0036, (2020/10/14)
The invention discloses a method for co-production of 2-methyl-6-nitrobenzoic acid and 3-nitro-2-methylbenzoic acid. The method is characterized by comprising the following steps: (1) feeding 3-nitro-o-xylene and dilute nitric acid into an oxidation reaction kettle, carrying out heating, and conducting reacting under certain pressure by using oxygen as an oxidant; (2) after the reaction is finished, discharging an oxidation reaction solution to obtain a crude product; (3) washing the crude product with water, conducting esterifying, and performing distilling to recover a solvent after the reaction is finished, thereby obtaining an esterified concentrated solution; (4) adding alkali into the esterification concentrated solution to adjust a pH value, carrying out layering, and distilling anorganic layer under reduced pressure to recover 3-nitro-2-nitrobenzoic acid; and (5) extracting a water layer with an organic solvent, adjusting an pH value with an acid, and performing filtering anddrying to obtain the 2-methyl-6-nitrobenzoic acid. In a low-concentration nitric acid environment, 3-nitro-2-nitrobenzoic acid is produced and 2-methyl-6-nitrobenzoic acid is co-produced with oxygen used as an oxidizing agent, so the problems of low selectivity of 3-nitro-o-xylene in an oxidation process and high risks in a concentrated nitric acid oxidation process are solved.
CO-production method 3 - nitro -2 - methyl benzoic acid and 3 -nitrophthalic acid (by machine translation)
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Paragraph 0019; 0023; 0027; 0031; 0035; 0041; 0045-0047, (2020/07/15)
The method comprises the following steps: (3 -) in nitric acid, oxidizing -2 - nitro-3 - methylbenzoic acid to 1 nitro 3 - methylbenzoic acid under the presence of a catalyst and an initiator; and (3 -) filtering to obtain the -2 -nitro 2 methylbenzoic acid crude product after the reaction is completed by heating while carrying out the reaction to complete the reaction and completing a 3 - nitro -2 -2 - methylbenzoic acid crude product after the reaction is completed, and the obtained crude 3 - product -2 - is obtained by recrystallizing the 4 mother liquor in the mother 3 - 1 liquor step (3) after the reaction is complete and the reaction is complete and the 3 - process is completed by carrying out the reaction on the 3 - mother liquor in the presence of a 3 - catalyst and an initiator to obtain the 3 -nitrobenzoic acid crude product. The method solves the problems of large waste water waste salt amount, difficult aftertreatment and serious environmental pollution in the prior art. (by machine translation)
Preparation method of 3-nitro-2-methylbenzoic acid
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Paragraph 0023-0038, (2020/07/15)
The invention discloses a preparation method of 3-nitro-2-methylbenzoic acid. The preparation method is characterized by comprising the following steps: (1) oxidizing 3-nitro-o-xylene into 3-nitro-2-methylbenzoic acid in an acidic organic solvent in the presence of a catalyst and an initiator by using oxygen as an oxidant; (2) after the reaction is finished, cooling, crystallizing and filtering toobtain a 3-nitro-2-methylbenzoic acid crude product; (3) re-crystallizing the 3-nitro-2-methylbenzoic acid crude product to obtain 3-nitro-2-methylbenzoic acid; wherein the acidic organic solvent inthe step (1) is acetic acid, propionic acid or a mixture of acetic acid and propionic acid, and the acidic organic solvent contains 0-17% by mass of water. According to the method, an organic acid isused as a solvent, a reaction is carried out under an appropriate reactant concentration, a reaction solution after the reaction is subjected to cooling crystallization to obtain a crude product of 3-nitro-2-methylbenzoic acid, and the crude product is re-crystallized to obtain a product with a purity of 98% or above. The preparation method solves the problems of large amount of waste water and waste salt, difficult post-treatment and serious environmental pollution in the prior art.
2-methyl-3-methoxybenzoyl chloride synthesizing process
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, (2019/03/15)
The invention discloses a 2-methyl-3-methoxybenzoyl chloride synthesizing process. According to the present invention, low-cost o-xylene is used as a starting raw material, the product is synthesizedby using a conventional synthesis method comprising nitrification, esterification, reduction, diazotization, methylation, acyl chlorination and other steps, and the total yield is controlled at more than 65%; the esterification of the intermediate product improves the separation degree of the intermediate; the reaction solvent is added in the diazotization step, such that the process parameters are relatively easy to control, and the purity of the intermediate in the diazotization step is more than 96% so as to provide the guarantee for the quality of the subsequent product; and with the synthesis process, the product quality is stable and reliable, and the cost is low.
Clean production method to oxidize 3-nitro-o-xylene into 2-methyl-3-nitrobenzoic acid
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Paragraph 0024-0047, (2019/07/04)
The invention discloses a clean production method to oxidize 3-nitro-o-xylene into 2-methyl-3-nitrobenzoic acid. The clean production method comprises the steps of adding 3-nitro-o-xylene with an acidinto an organic solvent under the action of a catalyst, adding an oxidant, and stirring to allow reacting to obtain 2-methyl-3-nitrobenzoic acid, wherein the oxidant is hydrogen peroxide, and the catalyst is a transition metal compound. The hydrogen peroxide is used herein as a clean oxidant, so that the oxidants, such as potassium permanganate, causing high environmental pollution are avoided. The reaction system is mild; post-reaction treatment is simple and practical; reaction selectivity is good; few byproducts are produced; the target product is easy to purify; both the yield and purityare high; the cost is low; the clean production method has a good industrial application prospect.
Combined production method for substituted benzaldehyde, substituted benzyl alcohol and substituted benzoic acid
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Paragraph 0077; 0078, (2017/01/31)
The invention discloses a combined production method for substituted benzaldehyde, substituted benzyl alcohol and substituted benzoic acid. The method comprises the following steps: (1) oxidation: a step of continuously introducing substituted toluene, a catalyst and oxygen-contained gas into an oxidation reactor and carrying out reaction so as to obtain oxidation reaction liquid; (2) hydrolyzation: a step of allowing the oxidation reaction liquid to continuously enter a hydrolysis reactor, and continuously adding water into the hydrolysis reactor and carrying out reaction so as to obtain a hydrolysis reaction mixture; (3) liquid-liquid layering: a step of layering the hydrolysis reaction mixture so as to obtain an oil phase and an aqueous phase; and (4) separation of products: a step of subjecting the oil phase to distillation so as to respectively obtain incompletely-reacted substituted toluene, substituted benzyl alcohol and substituted benzaldehyde, and subjecting the aqueous phase to cooling, crystallizing and filtering so as to obtain filtrate and substituted benzoic acid. The combined production method provided by the invention has the advantages of high raw material conversion rate, few by-products, good selectivity of target products, greenness and environmental protection.
Regioselectivity nitration of aromatics with N2O5 in PEG-based dicationic ionic liquid
Wang, Peng-Cheng,Lu, Ming
supporting information; experimental part, p. 1452 - 1455 (2011/05/16)
Regioselective mononitration of simple aromatic compounds has been investigated with N2O5 as nitrating agent and a new PEG200-based dicationic acidic ionic liquid (PEG200-DAIL) as catalyst. The results of experiments show that this nitration system can significantly improve the para-selectivity of alkyl-benzenes and the ortho-selectivity of halogenated-benzenes. The PEG200-DAIL exhibits recyclable temperature-dependant phase behavior in CCl4 solvent, and it can be recycled without apparent loss of catalytic activity, and only 5% loss of weight is observed after six times recycling.
INHIBITORS OF STEAROYL-COA DESATURASE
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, (2009/06/27)
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.
Aromatic nitration using nitroguanidine and EGDN
Oxley, Jimmie C.,Smith, James L.,Moran, Jesse S.,Canino, Jonathan N.,Almog, Joseph
, p. 4449 - 4451 (2008/12/21)
Acid catalyzed nitration has been examined using a variety of novel nitration agents: guanidine nitrate (GN) and nitroguanidine (NQ) as well as the simple nitrate ester, ethylene glycol dinitrate (EGDN). Reactions with either activated or deactivated aromatic substrates proceed rapidly and in high yield. Regioselectivity was similar for all nitrating agents examined. The synthetic advantages of liquid EGDN include high solubility in organic solvents, strong nitration activity and ease of preparation.
