44 results about "3-nitrobenzoic acid" patented technology

The present invention relates to a kind of new preparation method of 2-methyl-3-nitrobenzoic acid, it is characterized in that carry out by following steps: add 3-nitro-o-xylene, organic solvent and catalyst in reactor, pass into oxygen Oxidation, the oxidation temperature is 90-100 °C, when the mass concentration of 3-nitro-o-xylene in the reactor is less than 1% as the reaction end point, the crude product is obtained by cooling and filtering, and the mother liquor is recovered and recycled; the crude product is sequentially subjected to conventional alkalization methods, The finished product of 2-methyl-3-nitrobenzoic acid is obtained by activated carbon decolorization and acidification. The method of the present invention replaces nitric acid oxidation 3-nitro-o-xylene with oxygen in the air to become 2-methyl-3-nitrobenzoic acid, and adopts oxygen to oxidize 3-nitro-o-xylene, reacts at normal pressure, and applies mechanically to the mother liquor. The yield is up to 80%, and the invention is a clean production method with little risk, little pollution and low cost of raw materials.

The invention discloses a method for preparing lenalidomide (3-(7-amino-3-oxo-1H-isoindole-2-base) piperidine-2,6-diketone). Two intermediates of the lenalidomide are 2-halomethyl-3-nitro-benzoic acid methyl ester and 3-aminopiperidine-2,6-diketone. The invention discloses methods for preparing the two intermediates and preparing the lenalidomide by using the two intermediates. The method has novel process, short procedures, high reaction yield, low production cost, and larger implementation value and social and economic benefits.

A method for the manufacture of dabigatran of formula VIII, in which the product of a reaction of 4-ethylamino-3-nitrobenzoic acid chloride with ethyl-3-(pyridin-2-ylamino)propanoate, is converted to the hydrochloride using a hydrogen chloride solution producing the compound of formula III-HCl, in which the nitro group is reduced by means of a reaction with sodium dithionite, and the resulting compound of formula IV is subjected to a reaction with [(4-cyanophenyl)amino]acetic acid and oxalic acid, the product of this reaction VI-oxal is then subjected to hydrolysis and a reaction with ammonium carbonate to produce the intermediate of formula VII-HCl, which is then converted to dabigatran by means of a reaction with hexyl chloroformate.

The invention discloses a synthetic method of N-methyl-4-(methyl amino)-3-nitrobenzamide. The method comprises the following steps: firstly, 4-chloro-3-nitrobenzoic acid and methylamine react to generate 4-methyl amino-3-nitrobenzoic acid; then 4-methyl amino-3-nitrobenzoic acid and thionyl chloride have an acylating chlorination reaction to generate 4-(methyl amino)-3-nitrobenzoyl chloride; and finally, 4-(methyl amino)-3-nitrobenzoyl chloride and methylamine react to obtain the N-methyl-4-(methyl amino)-3-nitrobenzamide. The synthetic method of the N-methyl-4-(methyl amino)-3-nitrobenzamide has the advantages that raw material source is wide, the price and the production cost are low, the synthetic process is simple, the operation is simple and convenient, short time is consumed, the product yield is very high, and the total yield of the final product can reach 97.5%.