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.
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.
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.