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
-
Paragraph 0022; 0025; 0028; 0033, (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.
2-methyl-3-methoxybenzoyl chloride synthesizing process
-
, (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.